Efficient handling of l4s traffic in non-3GPP access using a cellular system

Abstract

Multiple techniques for handling ECN traffic are disclosed. In DL, an egress node can indicate to an ingress node that the egress node supports a capability of decapsulation. The ingress node keeps ECN markings via encapsulation translation from an inner part to an outer part in response to the capability of decapsulation. If there is no capability of decapsulation, the ingress node handles congestion through conventional mechanism(s). The ingress node can receive an indication from a UE that the UE supports a capability of decapsulation, and marks packets toward the UE about congestion. The UE determines there is congestion due to packet marking, and informs an App via indication(s). UL is basically the opposite of DL and ECN traffic can be handled in both.

Description

[0001] EFFICIENT HANDLING OF L4S TRAFFIC IN NON-3GPP ACCESS USING A

[0002] CELLULAR SYSTEM

[0003] TECHNICAL FIELD

[0004] Examples of embodiments herein relate generally to network communications and, more specifically, relate to Low Latency Low Loss Scalable throughput (L4S) traffic through both a non-3GPP and a cellular system.

[0005] BACKGROUND

[0006] L4S, or Low Latency, Low Loss, Scalable Throughput, is a network technology standard aimed at enhancing internet traffic performance. L4S drastically reduces latency, a crucial factor for applications like online gaming, video conferencing, and telemedicine. This enhancement leads to smoother, more reliable real-time interactions. Furthermore, by implementing scalable throughput and advanced AQM (active queue management) techniques, L4S optimizes data flow, reducing congestion and packet loss even during high-traffic periods.

[0007] One feature of L4S is the Explicit Congestion Notification (ECN) protocol, which is used for communication between network elements and hosts. This allows for identifying L4S traffic, ensuring this traffic receives the intended low-latency, low-loss service. L4S also allows for addressing congestion, through marking packets with a congestion experienced (CE) codepoint. For a transport protocol to provide scalable congestion control, the protocol provides feedback of the extent of CE marking on the forward path. This allows congestion to be addressed.

[0008] There are still issues with applying L4S to parts of a cellular network.

[0009] BRIEF SUMMARY

[0010] This section is intended to include examples and is not intended to be limiting.

[0011] In an exemplary embodiment, a method is disclosed that includes for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between the user plane function and a user equipment, determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user plane function, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non- 3 GPP intermediate network entity from the user plane function comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets have encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user equipment supports decapsulation for explicit congestion notification; and performing one of the following: based on the user equipment supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user equipment over a second tunnel between the non-3GPP intermediate network entity and the user equipment, the one or more packets with the explicit congestion notification markings; or based on the user equipment not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0012] An additional exemplary embodiment includes a computer program, comprising instructions for performing the method of the previous paragraph, when the computer program is run on an apparatus. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing the instructions embodied therein for use with the apparatus. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the apparatus.

[0013] An exemplary apparatus includes one or more processors and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between the user plane function and a user equipment, determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user plane function, the indication to the user plane function that the non- 3 GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user plane function comprise at least encapsulated explicit congestion notification markings; determining, by the non- 3 GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets have encapsulated explicit congestion notification markings; determining, by the non- 3 GPP intermediate network entity, whether the user equipment supports decapsulation for explicit congestion notification; and performing one of the following: based on the user equipment supporting decapsulation and determining that congestion was experienced, sending, by the non- 3 GPP intermediate network entity to the user equipment over a second tunnel between the non- 3 GPP intermediate network entity and the user equipment, the one or more packets with the explicit congestion notification markings; or based on the user equipment not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0014] An exemplary computer program product includes a computer-readable storage medium bearing instructions that, when executed by an apparatus, cause the apparatus to perform at least the following: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between the user plane function and a user equipment, determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user plane function, the indication to the user plane function that the non- 3 GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user plane function comprise at least encapsulated explicit congestion notification markings; determining, by the non- 3 GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets have encapsulated explicit congestion notification markings; determining, by the non- 3 GPP intermediate network entity, whether the user equipment supports decapsulation for explicit congestion notification; and performing one of the following: based on the user equipment supporting decapsulation and determining that congestion was experienced, sending, by the non- 3 GPP intermediate network entity to the user equipment over a second tunnel between the non- 3 GPP intermediate network entity and the user equipment, the one or more packets with the explicit congestion notification markings; or based on the user equipment not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0015] In another exemplary embodiment, an apparatus comprises means for: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between the user plane function and a user equipment, determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user plane function, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non- 3 GPP intermediate network entity from the user plane function comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets have encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user equipment supports decapsulation for explicit congestion notification; and performing one of the following: based on the user equipment supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user equipment over a second tunnel between the non-3GPP intermediate network entity and the user equipment, the one or more packets with the explicit congestion notification markings; or based on the user equipment not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0016] In an exemplary embodiment, a method is disclosed that includes for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, determining, by the user plane function, whether the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function using explicit congestion notification markings in one or more packets received for forwarding to the non-3GPP intermediate network entity, that congestion was experienced; performing one of the following: based on a determination the non- 3 GPP intermediate network entity supports decapsulation for explicit congestion notification, sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings; or based on a determination the non-3GPP intermediate network entity does not support decapsulation for explicit congestion notification, addressing by the user plane function the congestion via one or more mechanisms.

[0017] An additional exemplary embodiment includes a computer program, comprising instructions for performing the method of the previous paragraph, when the computer program is run on an apparatus. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing the instructions embodied therein for use with the apparatus. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the apparatus.

[0018] An exemplary apparatus includes one or more processors and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, determining, by the user plane function, whether the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function using explicit congestion notification markings in one or more packets received for forwarding to the non-3GPP intermediate network entity, that congestion was experienced; performing one of the following: based on a determination the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification, sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings; or based on a determination the non-3GPP intermediate network entity does not support decapsulation for explicit congestion notification, addressing by the user plane function the congestion via one or more mechanisms.

[0019] An exemplary computer program product includes a computer-readable storage medium bearing instructions that, when executed by an apparatus, cause the apparatus to perform at least the following: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, determining, by the user plane function, whether the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function using explicit congestion notification markings in one or more packets received for forwarding to the non-3GPP intermediate network entity, that congestion was experienced; performing one of the following: based on a determination the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification, sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings; or based on a determination the non-3GPP intermediate network entity does not support decapsulation for explicit congestion notification, addressing by the user plane function the congestion via one or more mechanisms.

[0020] In another exemplary embodiment, an apparatus comprises means for: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, determining, by the user plane function, whether the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function using explicit congestion notification markings in one or more packets received for forwarding to the non-3GPP intermediate network entity, that congestion was experienced; performing one of the following: based on a determination the non- 3 GPP intermediate network entity supports decapsulation for explicit congestion notification, sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings; or based on a determination the non-3GPP intermediate network entity does not support decapsulation for explicit congestion notification, addressing by the user plane function the congestion via one or more mechanisms.

[0021] In an exemplary embodiment, a method is disclosed that includes for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending indication, by the user equipment to the non-3GPP intermediate network entity, that the user equipment supports decapsulation for explicit congestion notification; receiving, by the user equipment, one or more packets over a tunnel from the user equipment to the non-3GPP intermediate network entity, the one or more packets comprising at least explicit congestion notification markings; decapsulating, by the user equipment, the one or more packets; determining, by the user equipment using the decapsulated one or more packets, that congestion has occurred in the tunnel; and sending, by the user equipment toward an application to which the one or more packets are directed, indication that congestion has occurred. An additional exemplary embodiment includes a computer program, comprising instructions for performing the method of the previous paragraph, when the computer program is run on an apparatus. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing the instructions embodied therein for use with the apparatus. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the apparatus.

[0022] An exemplary apparatus includes one or more processors and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending indication, by the user equipment to the non-3GPP intermediate network entity, that the user equipment supports decapsulation for explicit congestion notification; receiving, by the user equipment, one or more packets over a tunnel from the user equipment to the non-3GPP intermediate network entity, the one or more packets comprising at least explicit congestion notification markings; decapsulating, by the user equipment, the one or more packets; determining, by the user equipment using the decapsulated one or more packets, that congestion has occurred in the tunnel; and sending, by the user equipment toward an application to which the one or more packets are directed, indication that congestion has occurred.

[0023] An exemplary computer program product includes a computer-readable storage medium bearing instructions that, when executed by an apparatus, cause the apparatus to perform at least the following: for a user equipment connected to a non-third generation partnership project (non- 3 GPP) intermediate network entity, sending indication, by the user equipment to the non-3GPP intermediate network entity, that the user equipment supports decapsulation for explicit congestion notification; receiving, by the user equipment, one or more packets over a tunnel from the user equipment to the non-3GPP intermediate network entity, the one or more packets comprising at least explicit congestion notification markings; decapsulating, by the user equipment, the one or more packets; determining, by the user equipment using the decapsulated one or more packets, that congestion has occurred in the tunnel; and sending, by the user equipment toward an application to which the one or more packets are directed, indication that congestion has occurred.

[0024] In another exemplary embodiment, an apparatus comprises means for: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending indication, by the user equipment to the non-3GPP intermediate network entity, that the user equipment supports decapsulation for explicit congestion notification; receiving, by the user equipment, one or more packets over a tunnel from the user equipment to the non-3GPP intermediate network entity, the one or more packets comprising at least explicit congestion notification markings; decapsulating, by the user equipment, the one or more packets; determining, by the user equipment using the decapsulated one or more packets, that congestion has occurred in the tunnel; and sending, by the user equipment toward an application to which the one or more packets are directed, indication that congestion has occurred.

[0025] In an exemplary embodiment, a method is disclosed that includes for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between a user equipment and a user plane function, determining by the non-3GPP intermediate network entity to send indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user equipment, the indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non- 3 GPP intermediate network entity from the user equipment comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets has encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user plane function supports decapsulation for explicit congestion notification; and performing one of the following: based on the user plane function supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user plane function over a second tunnel between the non-3GPP intermediate network entity and the user plane function, the one or more packets with the explicit congestion notification markings; or based on the user plane function not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0026] An additional exemplary embodiment includes a computer program, comprising instructions for performing the method of the previous paragraph, when the computer program is run on an apparatus. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing the instructions embodied therein for use with the apparatus. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the apparatus.

[0027] An exemplary apparatus includes one or more processors and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between a user equipment and a user plane function, determining by the non-3GPP intermediate network entity to send indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user equipment, the indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user equipment comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets has encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user plane function supports decapsulation for explicit congestion notification; and performing one of the following: based on the user plane function supporting decapsulation and determining that congestion was experienced, sending, by the non- 3 GPP intermediate network entity to the user plane function over a second tunnel between the non- 3 GPP intermediate network entity and the user plane function, the one or more packets with the explicit congestion notification markings; or based on the user plane function not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0028] An exemplary computer program product includes a computer-readable storage medium bearing instructions that, when executed by an apparatus, cause the apparatus to perform at least the following: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between a user equipment and a user plane function, determining by the non-3GPP intermediate network entity to send indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user equipment, the indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user equipment comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets has encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user plane function supports decapsulation for explicit congestion notification; and performing one of the following: based on the user plane function supporting decapsulation and determining that congestion was experienced, sending, by the non- 3 GPP intermediate network entity to the user plane function over a second tunnel between the non- 3 GPP intermediate network entity and the user plane function, the one or more packets with the explicit congestion notification markings; or based on the user plane function not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0029] In another exemplary embodiment, an apparatus comprises means for: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between a user equipment and a user plane function, determining by the non-3GPP intermediate network entity to send indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user equipment, the indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non- 3 GPP intermediate network entity from the user equipment comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets has encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user plane function supports decapsulation for explicit congestion notification; and performing one of the following: based on the user plane function supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user plane function over a second tunnel between the non-3GPP intermediate network entity and the user plane function, the one or more packets with the explicit congestion notification markings; or based on the user plane function not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0030] In an exemplary embodiment, a method is disclosed that includes for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending, by the user plane function to the non-3GPP intermediate network entity, indication that the user plane function supports decapsulation for explicit congestion notification; receiving, by the user plane function from the non-3GPP intermediate network entity, one or more packets having explicit congestion notification markings; performing, by the user plane function, decapsulation of the one or more packets to determine that the explicit congestion notification markings are in the one or more packets; and sending, by the user plane function toward a destination, the one or more packets with markings indicating congestion has occurred.

[0031] An additional exemplary embodiment includes a computer program, comprising instructions for performing the method of the previous paragraph, when the computer program is run on an apparatus. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing the instructions embodied therein for use with the apparatus. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the apparatus.

[0032] An exemplary apparatus includes one or more processors and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending, by the user plane function to the non-3GPP intermediate network entity, indication that the user plane function supports decapsulation for explicit congestion notification; receiving, by the user plane function from the non-3GPP intermediate network entity, one or more packets having explicit congestion notification markings; performing, by the user plane function, decapsulation of the one or more packets to determine that the explicit congestion notification markings are in the one or more packets; and sending, by the user plane function toward a destination, the one or more packets with markings indicating congestion has occurred.

[0033] An exemplary computer program product includes a computer-readable storage medium bearing instructions that, when executed by an apparatus, cause the apparatus to perform at least the following: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending, by the user plane function to the non-3GPP intermediate network entity, indication that the user plane function supports decapsulation for explicit congestion notification; receiving, by the user plane function from the non-3GPP intermediate network entity, one or more packets having explicit congestion notification markings; performing, by the user plane function, decapsulation of the one or more packets to determine that the explicit congestion notification markings are in the one or more packets; and sending, by the user plane function toward a destination, the one or more packets with markings indicating congestion has occurred.

[0034] In another exemplary embodiment, an apparatus comprises means for: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending, by the user plane function to the non-3GPP intermediate network entity, indication that the user plane function supports decapsulation for explicit congestion notification; receiving, by the user plane function from the non-3GPP intermediate network entity, one or more packets having explicit congestion notification markings; performing, by the user plane function, decapsulation of the one or more packets to determine that the explicit congestion notification markings are in the one or more packets; and sending, by the user plane function toward a destination, the one or more packets with markings indicating congestion has occurred.

[0035] In an exemplary embodiment, a method is disclosed that includes for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, receiving indication, by the user equipment from the non-3GPP intermediate network entity, that the non- 3 GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user equipment, congestion has occurred for one or more packets; and sending, by the user equipment toward the non-3GPP intermediate network entity, the one or more packets that are marked with explicit congestion notification markings. An additional exemplary embodiment includes a computer program, comprising instructions for performing the method of the previous paragraph, when the computer program is run on an apparatus. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing the instructions embodied therein for use with the apparatus. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the apparatus.

[0036] An exemplary apparatus includes one or more processors and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, receiving indication, by the user equipment from the non-3GPP intermediate network entity, that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user equipment, congestion has occurred for one or more packets; and sending, by the user equipment toward the non-3GPP intermediate network entity, the one or more packets that are marked with explicit congestion notification markings.

[0037] An exemplary computer program product includes a computer-readable storage medium bearing instructions that, when executed by an apparatus, cause the apparatus to perform at least the following: for a user equipment connected to a non-third generation partnership project (non- 3 GPP) intermediate network entity, receiving indication, by the user equipment from the non- 3 GPP intermediate network entity, that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user equipment, congestion has occurred for one or more packets; and sending, by the user equipment toward the non-3GPP intermediate network entity, the one or more packets that are marked with explicit congestion notification markings.

[0038] In another exemplary embodiment, an apparatus comprises means for: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, receiving indication, by the user equipment from the non-3GPP intermediate network entity, that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user equipment, congestion has occurred for one or more packets; and sending, by the user equipment toward the non-3GPP intermediate network entity, the one or more packets that are marked with explicit congestion notification markings.

[0039] BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings use reference numerals, where the same reference numerals may be used to refer to like parts throughout, but parts having the same reference numeral can differ in operation and components. In the attached drawings:

[0041] FIG. 1 is a block diagram illustrating congestion scenarios in downlink;

[0042] FIG. 1A is block diagram illustrating congestion scenarios in downlink when implementing an exemplary embodiment herein;

[0043] FIG. 2 is a block diagram illustrating ECN-Decap capability indication exchange in a generic scenario with ingress and egress interfaces of a tunnel;

[0044] FIG. 3 is a block diagram illustrating ECN-Decap capability indication when NWu / NWt Network is congested in a specific n3GPP (un)trusted NW;

[0045] FIG. 4 is a block diagram illustrating ECN-Decap capability indication when N3 Network is congested in n3GPP transport NW;

[0046] FIG. 5 is a block diagram illustrating ECN-Decap capability indication in Uplink for L4S traffic; FIG. 6 is a signaling diagram illustrating a L4S mechanism for trusted / untrusted non-3GPP access, N3IN; and

[0047] FIG. 7 is a block diagram of one possible and non-limiting exemplary system in which the exemplary embodiments may be practiced.

[0048] DETAILED DESCRIPTION OF THE DRAWINGS

[0049] Abbreviations that may be found in the specification and / or the drawing figures are defined below, at the end of the detailed description section.

[0050] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. All of the embodiments described in this Detailed Description are exemplary embodiments provided to enable persons skilled in the art to make or use the examples.

[0051] When more than one drawing reference numeral, word, or acronym is used within this description and in general as used within this description, the may be interpreted as “or”, “and”, or “both”. As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or,” mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0052] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0053] It is noted that capital and lowercase words or phrases are considered to be the same herein. For instance, the words Slice and slice are the same, as are the phrases Network Repository Function and network repository function.

[0054] Any flow diagram or signaling diagram herein is considered to be a logic flow diagram, and illustrates the operation of an exemplary method, results of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and / or interconnected means for performing functions in accordance with an exemplary embodiment. Block diagrams (such as FIG. 7) also illustrate the operation of an exemplary method, results of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and / or interconnected means for performing functions in accordance with an exemplary embodiment. For methods, flow diagrams, and signaling diagrams, the orders of method steps, blocks in the flow, or signaling are not critical and instead are examples.

[0055] Technical context is now provided for areas related to the understanding of the examples. The examples relate to how information, particularly packets, travel through a network, partly via a cellular network, to parts of the network that are outside the cellular network, such as Wi-Fi, via a non-3GPP intermediate network node. This also involves a protocol stack, there the highest layer is typically the application layer, supporting applications like web browsers, video, extended reality, and the like, and the lowest layer is a physical layer (PHY) that performs the actual transmission and reception of information such as packets. The examples also apply L4S in a network that involves a cellular network, particularly a core network, and review of L4S concepts is helpful.

[0056] For instance, one applicable service is an L4S. An L4S service would allow network administrators to configure their routers to mark the packets as per CE (congestion experienced) if a configured policy threshold is exceeded. The L4S-Prague compatible transport / higher layers could then deduce the amount of congestion by the ratio of normal versus CE-marked packets and thus are able to reduce the sending rate accordingly. During normal operation, this method could completely avoid packet drops caused by congestion and retain high utilization and low latency.

[0057] Another relevant topic is ECN Marking for L4S traffic. ECN stands for Explicit Congestion Notification and this is implemented as an algorithm. This algorithm has only one responsibility: to inform the sender about congestion building at the routers. Hence, ECN is a congestion notification or congestion signaling algorithm and may use Congestion Experienced, CE, markings (e.g., code points) to inform of congestion. ECN informs the sender about congestion so that respective measures can be taken (e.g., reducing the application generated data and resulting sending rate) to avoid congestion. The algorithm, because the assumption is that congestion is widely interpreted as also receiving a higher packet rate for an application than wanted by a node policy, can be used to control the rate of the application to match the policy of that node, even if that node is not in a “congested” state.

[0058] There is a KI#3 of 3 GPP SA2 Study on XRM (Extended Reality and Media service) in Rel. 18. For this KI, to support Extended Reality (XR) in 3GPP networks, SA2 for Release 18 has studied mechanisms that enable codec / rate adaptation to meet requirements for services as described in 3 GPP TS 23.700-60, in KI 3. Two options are concluded in stage 2 conclusions for KI#3.

[0059] From the conclusions of TR 23.700-60, two ways the congestion information can be conveyed back to the application (for rate adaptation) are as follows.

[0060] 1) Option 1 (By enabling L4S): The 5G System may use ECN marking for the purpose of Low Latency, Low Loss and Scalable Throughput services L4S for uplink and / or downlink QoS Flows via one of the following two methods. A QoS Flow level explicit indication may be provided to PSA UPF to enable the ECN marking for the purpose of L4S. a) Methodi: To support L4S, NG-RAN performs ECN marking for uplink and downlink in IP layer of the received packets.

[0061] NOTE 1: The criteria for RAN to determine (e.g. its congestion level) when to perform the marking is up to RAN implementation. b) Method2: PSA UPF performs ECN marking for uplink and downlink IP layer of the received packets based on latest reported congestion information from NG-RAN via GTP- U header. When no congestion / congestion ends, the PSA UPF stops ECN marking.

[0062] 2) Option 2 (via API based exposure): The 5G System also may support API based exposure of congestion level information towards AF.

[0063] Another topic is 3GPP SA2 Rel 19 New Study on XRM. The new approved SID titled Study on Architecture enhancement for XRM Ph2 (SP-231198) includes the below non-3GPP aspects to be studied as part of Rel-19:

[0064] WT#3 Further enhancement to support XR based on non-3GPP access.

[0065] WT#3.1 Study how to support L4S for non-3GPP access networks and intermediate 5GS nodes (N3IWF, TNGF and W-AGF) to perform ECN marking for L4S.

[0066] - Support L4S in untrusted / trusted access (e.g. N3IWF, TNGF).

[0067] - Support L4S in wireline access (e.g. W-AGF).

[0068] More details about the control plane protocol stack are provided now. At the end of the registration procedure, a signaling IPsec SA is established between the UE and the N3IWF, after which the UE transports the NAS mobility and session management messages over the inner IP layer and the signaling IPsec SA. IPsec tunnel mode is employed for the signaling SA to protect and encrypt the original IP signaling packets and the port numbers used for communications of such IP packets.

[0069] Concerning the user plane (U-plane) protocol stack, the U-Plane protocol stack involves the protocols used in the UE, WLAN (e.g., an access point), N3IWF and UPF for transferring the UP traffic between the UE and data network. An IPsec tunnel mode is employed for the established Child SAs to protect and encrypt the original IP user data packets and the port numbers used for communications of such IP packets. With respect to inner and outer IP header handling, in case of non-3GPP interfaces such as N3IWF / TNGF, IP-to-IP layer protocol conversion may be required. The inner IP layer packets (e.g., header information) of the UPF needs to be encrypted / encapsulated into outer IP layer packets at N3IWF and the N3IWF needs to decry pt / decapsulate the header information. The encapsulation / decapsulation happens using IETF RFC 3819 : B. Briscoe and J. Kaippallimalil, “Guidelines for Adding Congestion Notification to Protocols that Encapsulate IP”, draft-ietf- tsvwg-ecn-encap-guidelines-22, 5 December 2023.

[0070] As per a Rel 19 Study work task, L4S-specific enhancements are to be made for non-3GPP access nodes such as N3IWF, TNGF, or W-AGF when there is congestion experienced in those intermediate nodes.

[0071] Note that, throughout the rest of the description herein, the term non-3GPP Intermediate Node (N3IN) is used to denote all three intermediate access nodes: N3IWF, TNGF and W-AGF. N3IWF, TNGF, and W-AGF are not typical access nodes. One can also use “non 3GG intermediate network entity” to designate these nodes. For instance, consider the N3IWF. Untrusted Wi-Fi (e.g., 802.11) access is considered, since the large majority of UEs have both a 3 GPP radio interface and a Wi-Fi interface. Untrusted refers to the fact that non-3GPP access (i.e., the Wi-Fi Access Point) is assumed to be not managed by the same operator of the 5G network: as an example, a hotspot into an airport, or a private home Wi-Fi router. For this reason, an end-to-end security association between UE and N3IWF is established, regardless of the one established in the access at layer 2. The N3IWF is in charge to “adapt” access and authentication protocols of the non-3GPP Wi-Fi section towards the 5GC, interfacing with the 5GC with the same role of the RAN (i.e., enabling N2 and N3). Meanwhile, TNGF provides trusted Wi-Fi. That is, in a scenario of trusted Wi-Fi, the access function is called Trusted Non-3GPP Access Network (TNAN). TNAN is split in two parts, the Trusted Non-3GPP Access Point Function (TNAP) and Trusted Non-3GPP Gateway Function (TNGF), which interfaces with the 5GC. Other types of access different from Wi-Fi have been defined, with particular reference to fixed access represented by domestic broadband modems. The same approach in line of principle could be extended to other fixed access technologies, including satellite-based ones. In this scenario, a new Wireline 5G Access network (W-5GAN) gateway function is defined in the core network. W-5GAN includes the Wireline Access Gateway Function (W-AGF), which is equivalent to TNGF for what concerns its functionalities and interfaces / relation with the CN. W-AGF is part of the landline core ISP infrastructure and connected to the core network, enabling N2 / N3 interfaces. This can as well access via 3GPP to the core network.

[0072] Whether a node is 3 GPP or non-3GPP can be determined via the Radio Access Technology (RAT) being used. The RAT type identifies the transmission technology used in the access network for both 3 GPP accesses and non-3GPP Accesses, for example, NR (3 GPP), NB-IOT (Narrowband Internet of things) (non-3GPP), Untrusted Non-3GPP (non-3GPP), Trusted Non-3GPP (non- 3GPP), Trusted IEEE 802.11 Non-3GPP access (non-3GPP), Wireline (non-3GPP), Wireline- Cable (non-3GPP), Wireline-BBF (broadband forum) (non-3GPP), and the like. Furthermore, a 3GPP RAT is defined by one or more 3GPP TSs, while a non-3GPP RAT is not. More specifically, the following types of non-3GPP access networks are defined: Untrusted non-3GPP access networks; Trusted non-3GPP access networks; and Wireline access networks. See 3 GPP TS 23.501, clause 4.2.8.0 and more generally clause 4.2.8.

[0073] When 5G traffic is transmitted via non-3GPP intermediate access nodes (such as N3IWF, TNGF, or W-AGF), two separate IP tunnels are created in the Downlink (DL) direction; (la) Between UPF and N3IN and (lb) Between N3IN and UE. Similarly for the Uplink (UL) traffic, two IP tunnels are created in the Uplink (UL) direction; (2a) Between UE and N3IN and (2b) Between N3IN and UPF.

[0074] In the DL, as per IETF RFC (see “Guidelines for Adding Congestion Notification to Protocols that Encapsulate IP”, cited above), the UPF 99-1 should first encapsulate the inner IP header ECN markings (and possibly other header information) to its outer header (tunnel IP header). When N3IN gets the IP header, the N3IN may or may not be able to decapsulate the encapsulated ECN markings. This is valid for both tunnels (tunnel la and lb) scenario, see FIG. 1. FIG. 1 is a block diagram illustrating congestion scenarios in downlink. This figure includes a UE 10, an N3IN 210, a UPF 99-1, and a source (Src) 220, all in a network (NW) 100. As shown in FIG. 1, congestion experienced 230 may happen in any of the queues, e.g., egress of the UPF (see congestion experienced 230-1) or in the N3 link (via tunnel la 145) (see congestion experienced 230-2) or at the egress of N3IN 230-3 (see congestion experienced 230-3). This example involves an inner part 110, where inner IP header, possibly with ECN markings, is used, and an outer part 120, with an outer IP header. It is noted that the inner part will also be referred to herein simply as “inner”, and the outer part will also be referred to herein simply as “outer”. Assume the IP layer 102 marks packets 105, where k% (k percent) of the packets are marked with ECN markings in the inner IP header, and k is a certain percentage such as 20 as one nonlimiting example. The UPF 99-1 performs encapsulation 130 to translate from the inner IP header to the outer IP header, which is used for the Tunnel la 145. There is also a transition at the N3IN 210 from tunnel la 145 to tunnel lb 155. Note that there is a Wi-Fi AP (access point) 160 in between the N3IN 210 and the UE 10, but this is not in the 3 GPP scenario, so is not considered here.

[0075] Therefore, in order to carry out the smooth transition (encapsulation / decapsulation) of the ECN markings between the tunnels 145, 155, the source of the tunnels (e.g., UPF for the first DL tunnel (la 145) and N3IN for the second tunnel (lb 155)) should ensure that the receiving ends (e.g., N3IN for the first tunnel (la 145) and UE for the second tunnel (lb 155)) of the tunnel are capable of decapsulating the ECN markings. In case N3IN is not capable of correctly ECN-Decap (ECN- decapsulating, shown as decapsulating 140) the outer CE marks into the inner IP.ECN header, the ECN marks will be lost. This typically results in fallback to a normal mechanism of dealing with congestion, which is illustrated by block 150, where if there is no decapsulating 140, the N3IN addresses congestion via normal mechanism(s) such as dropping packets. Hence, if this support is not ensured, then the upstream nodes that are involved (e.g., UPF, AF, and the like) in the ECN mechanism, may not be aware of this and assume that L4S mechanism is working fine, whereas in reality the L4S mechanism has been broken midway and the expected rate control may not be applied at the source in case of actual congestion. This will have further negative impacts on the network resources, QoS / QoE of the application, and the like. A similar issue can be there in the uplink direction.

[0076] Thus, there are problems associated with implementations that use the L4S mechanism.

[0077] The examples herein address at least these problems. Consider FIG. 1A, which is block diagram illustrating congestion scenarios in downlink when implementing an exemplary embodiment herein. In this example, in block 130-1, the UPF receives or does not receive an indication from the N3IN of ECN-decap support by the N3IN. In response to reception, the UPF 99-1 keeps markings via encap (encapsulating) translated to the outer part 120 or in response to no reception, the UPF 99-1 does not keep the markings when performing the encap translated to the outer part 120. In block 150-1, the N3IN 210 receives or does not receive an indication from UE of ECN- decap support; if support, the N3IN performs decap and marks the packets to the UE; if no ECN- decap support, the N3IN addresses congestion via conventional mechanism(s) (e.g., drop packets or forward the packets without, w / o, the ECN markings). In one example, the N3IN (which may be the same node but within different layers) gets a packet, reads its header and that packet is forwarded to the UE by putting another header on-top. One technique to mark the packets is to read marks from an incoming packet and copy and mark in the overlay header for those packets. Assuming the N3IN 210 supports ECN-decap support, the UPF then keeps the ECN markings via encapsulation of the outer IP header, the N3IN receives packets with the encapsulated ECN markings via encapsulation of the outer IP header. The N3IN after decapsulation and the N3IN (e.g., the ECN part of the same) marks the DL packets because of the received ECN-decapsulation support indication. The UE in block 170 determines because of the marked DL packets there is congestion, and informs the App (application 125) via one or more indication(s). The flow of packets is directed to the App 125 in DL. In block 180, the application (App) 125 receives indication(s) of congestion, and adjusts accordingly, e.g., App 125 feeds back to App 135, as one example. Other examples include the App 125 adjusting its requests to request less data.

[0078] In further detail, one example herein is to introduce support for an ECN Encapsulation / Decapsulation capability indicator between the UE and the network.

[0079] 1) The L4S-ID consists of two codepoints, both identify L4S packets. One value represents CE state and other represents non-CE state of the packet. The unique L4S-IDs for IP layer is IP.ECN=0x01 / mask=0x01 (mapping to ECT_l==L4S_ID==0x01 and CE=0x03 codepoints of ECN).

[0080] 2) For the downlink (and may be applicable for UL also) L4S QoS traffic, an L4S Id other than the IP.ECN codepoints is created and included in an outer header during encapsulation to distinguish L4S traffic in tunneled traffic, based the AF / application’s IP.ECN codepoints. This proxy-L4S.Id helps to differentiate L4S traffic from non-L4S traffic (possibly QoS flows comprise a mix of L4S and non-L4S traffic).

[0081] 3) For end-to-end handling of the L4S Id, each intermediate NFs and nodes should carry the codepoints in a consistent way (even when remapped to other values on the way, the meaning needs to be kept throughout the network and only transitions from L4S-ID / non-CE to L4S-ID / CE are allowed). Here, the term “consistent way” means each intermediate node should support the same L2 QoS codepoints, for example DSCP or PCP (802. Ip) or VLAN or DEI codepoints can be configured on each intermediate node, which would be an additional or alternative classifier / CE- 1 marker carrier across the network. Thus, this CE marking will be carried forwarded in a consistent way.

[0082] A number of exemplary embodiments are described now: Embodiment 1 - Downlink Encap-Decap Support Handling; Embodiment la - Downlink Encap-Decap Support Handling in Lower than IP layers (i.e., in L2 layer); and Embodiment 2 - Uplink Encap-Decap Support Handling. Embodiments are not limited to these.

[0083] Described first is Embodiment 1 - Downlink Encap-Decap (Encapsulation-Decapsulation) Support Handling. In this embodiment, an ingress node ensures that the corresponding egress node of a tunnel will propagate any congestion notification added to the outer header over the path.

[0084] If the egress node of the tunnel can support decapsulating the collected ECN-CE markings (e.g., CE codepoint) finally into the inner IP header (possibly via several intermediate steps and possibly by the same or subsequent nodes), the ingress node should encapsulate the ECN field information from inner IP to outer IP packets. Otherwise, the outer IP header ECN field may be set to 0x00 (not-ECT codepoint) by the ingress node. If the application is not supporting L4S, then the inner IP.ECN field will already have the value 0x00.

[0085] In the DL direction, N3IN indicates the ECN-Decap support to UPF / SMF. N3IN may indicate this support indication in GTP-U message to the UPF or in an N2 message to an SMF.

[0086] Similarly, the UE 10 should indicate the ECN-Decap support to N3IN in the IP Sec SA signaling.

[0087] For example, when there is a congestion in the N3IN itself (for instance in the NWu / NWt interface or in the processing CPU or internal application queues) and the N3IN can set the inner IP.ECN field directly to the CE codepoint, then no decap functionality of the UE is required, only application L4S support, which is visible from having the L4S-ID in the inner IP.ECN field. If the UE supports decapsulation, then the N3IN can set either the inner or the outer IP.ECN or both to the CE codepoint.

[0088] For example, consider FIG. 2, which is a block diagram illustrating ECN-Decap capability indication exchange in a generic scenario with ingress and egress interfaces of a tunnel. It is noted that the reference number 145 for the tunnel la is shown, as is the reference number 155 for the tunnel lb, but the tunnels are not shown in this or subsequent figures. This figure uses a source (Src) 220, an ingress node 330, an egress node 340, and a destination 350. When there is a congestion in NWu / NWt access (where NWu (untrusted) / NWt (trusted) are the interfaces for the non 3 GPP access (WLAN / Wi-Fi, for example)), the network as shown in FIG. 2, can address this via the ECN-Decap support info: {ECN_decap = Yes / No} (see reference 360) from UE (e.g., the Dest 350), which will be known by N3IN (e.g., the egress node 340). In this example, the UE supports decapsulation (e.g., the Dest 350), N3IN (as egress node 340) sets outer IP.ECN as L4S- ID (the information copied from inner IP.ECN field: L4S-ID). The congestion in the NWu / NWt itself, can in this case be reported via setting the outer IP.ECN as CE (as the inner is not accessible due to encryption). The decapsulation capability of the UE will ensure that this CE mark will become visible to the application by copying the CE to the inner IP.ECN field. Block 380 indicates that ECN-encap is performed by the ingress 330 if the ECN-decap from the egress 340 is true. That is, in block 390, in response to the UE indicating it supports ECN-decap, egress 340 indicates (360) it supports ECN-decap to ingress 330. In block 391, in response to the egress indicating it supports ECN-decap (e.g., ECN-decap = true), ingress 330 keeps ECN markings via encap translation from inner to outer.

[0089] Similarly, congestion in the N3 transport network can be handled when L4S capability is made visible when the N3IN is L4S decapsulation capable as shown in FIG. 3. This example includes UE 10, an N3IN 210 (e.g., one of N3IWF or TNGF), UPF 99-1 and DN 91. Internal UPF congestion or in the interface towards its N3 link (see congestion experienced 230) can be handled by the UPF 99-1 directly in the inner IP.ECN and / or also in the outer IP.ECN field if knowing the ECN-Decap support of N3IN. In this example, the UE sends an indication 410-1 indicating the UE 10 is ECN-decap capable to the N3IN 210, and the N3IN 210 sends an indication 410-2 indicating the N3IN 210 is ECN-decap capable to the UE 10.

[0090] This allows the UE 10 to perform block 470, where the UE sends ECN-decap capable to N3IN, and the UE can perform block 170 (the UE determines there’s congestion due to packet marking, informs App via indication(s)). The N3IN in block 450 receives indication from UE of ECN- decap support; performs the decap (in response to ECN-decap support = true in 380-1); and also sends indication of ECN-decap support to UPF. The UPF in block 491, in response to the egress indicating it supports ECN-decap (e.g., ECN-decap = true in 380-2), the UPF keeps the ECN markings via encap translation from inner to outer. It is noted that the interface 493 between the N3IN 210 and the UE 10 in FIG. 3 is the NWu / NWt interface and the N3 network 495 is shown as (e.g., part of) the 3 GPP network. FIG. 4 illustrates where this interface 494 is a NR-Uu interface, where the NR-Uu interface is typically for 3 GPP access (between RAN and UE), but here it is being used for a non-3GPP access interface. That is, FIG. 4 is a block diagram illustrating ECN-Decap capability indication when N3 network 495 is congested (corresponding to the congestion experienced 230) in n3GPP (non-3GPP) transport NW, shown at least via the NR-Uu 494. In block 450-1, the N3IN 210 sends indication of ECN- decap support to UPF; and performs decap. In block 491-1, in response to the N3IN indicating it supports ECN-decap (e.g., ECN-decap = true in 380), UPF keeps ECN markings via encap translation from inner to outer.

[0091] Another example concerns Embodiment la - Downlink Encap-Decap Support Handling in Lower than IP layers (i.e., in L2 layer). If a tunneling protocol is not over IP or if the transport or access NW does not support IP, Layer2 (e.g., of WLAN or Ethernet) QoS mechanisms can be used to classify L4S traffic (e.g., with the ECN markings). Codepoints for L4S-ID and CE are operator defined / configurable for VLAN or PCP (802.1p-bit) and optionally for DEI values in the underlying NW configuration. Additionally, extra DSCP codepoints can be configured which would be useful for operators and would be another potentially additional or alternative classifier / CE-marker carrier. For instance, consider the following:

[0092] 1) There should be a static configuration (operator configurable mapping or implementation specific) in an intermediate transport node to map the IP.ECN L4S ID (which includes also CE) to a L2.PCP codepoint, and when receiving packets that a L2.PCP == CE (remarked from L2.PCP == L4S ID to L2.PCP == CE by an intermediate NW node) to set that L2.PCP == CE into the IP.ECN. In a similar way, L2.VLAN codepoints also can be used in this mapping. Alternatively, a single L4S-ID value can be used if the L2.DEI is used for indicating non-CE or CE.

[0093] 2) Similarly, the IP.ECN L4S ID (which includes also CE) can be mapped to an IP. DSCP codepoint in an IP tunneled network, and when receiving packets that an IP. DSCP == CE (remarked from IP.DSCP == L4S ID to IP. DSCP == CE by an intermediate NW node) can set that into the IP.ECN.

[0094] In an alternative method, the egress node announces its ECN-Decapsulation functionality along with the supported L2 QoS fields in the {ECN-Decap-capability-set} via user-plane signaling (e.g. , during N3 GTP-U tunnel establishment). For instance, ECN-Decap capability set can be {ECN decap = Yes; DSCP (PCP / 802. Ip DEI) mapping to CE == Yes}. If the ingress node knows that the transport egress nodes can support ECN Decap and L2 / L3 QoS codepoints corresponds to CE, then the ingress node should encapsulate the ECN field information from inner IP to outer IP packets, which are received by the egress node. In this way, CE codepoint(s) cannot be lost, and the CE codepoint(s) will be preserved E2E. That is, the same L2 QoS codepoints, for example DSCP or PCP (802. Ip) or VLAN or DEI codepoints, are sent by the ingress node 330 and received by the egress node 340.

[0095] In another alternative method, the ingress node needs to verify the E2E ECN CE preservation capability using its configured L4S-CE codepoint, by setting this codepoint on an initial establishment packet. A capable egress node will verify if this initial packet contains the L4S-CE codepoint configured locally in this egress node and if it can guarantee the propagation towards the inner IP.ECN field (possibly via mapping to other codepoints which result to IP.ECN update by further nodes on the path), the egress node will send a CE-received-acknowledgement-reply- indication to the ingress node. The ingress node activates the encap functionality only when the CE-received-acknowledgement-reply-indication is received. In this way, remapping in intermediate nodes (for example over different administrator domains on domain edges) can be supported that remap the L4S-CE codepoint from one codepoint / header to another, which cannot be checked with the capability check which assumes that the same E2E codepoints are used and preserved. Additionally, this method verifies that the E2E traversal is effectively functioning.

[0096] It should be noted that if a L2 NW can be dimensioned to be non-blocking for L4S, only a single 802. Ip codepoint can be used to identify L4S traffic and to classify it in a higher priority queue. In this way L4S traffic leaves enough capacity for lower priority services, and we get a low latency, loss and jitter L4S service on the full transport or access pipe (zero queuing latency).

[0097] Another example is Embodiment 2 - Uplink Encap-Decap Support Handling. This part concerns FIG. 5, which is a block diagram illustrating ECN-Decap capability indication in Uplink for L4S traffic. In this example, the UPF 99-1 sends an indication 410-1 indicating the UPF 99-1 is ECNdecap capable to the N3IN 210, and the N3IN 210 sends an indication 410-2 indicating the N3IN 210 is ECN-decap capable to the UPF 99-1. There is congestion experienced 230 between the UE 10 and N3IN 210. In further detail, in block 510, the UE receives ECN-decap support from the N3IN, and (in response) the UE performs ECN markings via encap translated to outer. That is, the UE may mark the CE bits in response to the UE receiving the decap capability indication from the N3IN and a determination that congestion has occurred for packet(s). Otherwise, the UE may report back to upper layers or drop packets, and / or perform other mechanism(s). In block 530, if the N3IN has ECN-decap support, the N3IN keeps ECN markings (e.g., via marking packets toward the UPF or keeping encap translated from inner to outer). It is noted that if there no ECN-decap support, the N3IN may address congestion via conventional mechanism(s) (e.g., drop packets or forward the packets without, w / o, the ECN markings). It is noted other mechanisms are possible, such as those mechanisms defined in IETF (RFC 9331, 6040 for details), such as AQM (Active Queue Management), fair queue model, and the like. The mechanisms may be combined. The UPF in block 560 sends indication of ECN-decap support to N3IN; and performs decap and marks UL packets to the DN. If there is no ECN-decap support, the UPF may address congestion via conventional mechanism(s). The DN in block 570 determines there is congestion due to packet marking, and informs the App 135 via indication(s). The App 135 in block 580 receives indication of congestion, adjusts accordingly, e.g., App 135 feeds back to App 125. Other options are possible, such as the App 135 throttling the data rate or sending lower quality video, among many other options.

[0098] For upstream L4S traffic the N3IN and / or UPF should inform the SMF (not shown) of its ECN- Decapsulation capabilities during initialization. Subsequently, the UE and / or the N3IN should to be informed of the respective N3IN and / or UPF’s ECN-Decapsulation capabilities by the SMF. Consider the following:

[0099] 1) The UPF should indicate the ECN-Decap support to N3IN for uplink L4S traffic flow.

[0100] 2) Similarly, N3IN should indicate the ECN-Decap support to UE for uplink L4S traffic flow.

[0101] Another example is Embodiment 2a - Uplink Encap-Decap Support Handling in Lower than IP layers. This embodiment is similar to Embodiment la except that this is for uplink.

[0102] A further example concerns downlink and is described in reference to FIG. 6, which is a signaling diagram illustrating an L4S mechanism for trusted / untrusted non-3GPP access, N3IN. FIG. 6 is valid for any N3IN such as N3IWF, TNGF or W-AGF besides the UE - W-AGF interface, which does not establish an IPSec tunnel. Note that an implicit trigger 610 is illustrated, and an explicit trigger 620 is illustrated. These might not both be used. The involved entities are the UE 10, a non- 3 GPP AP 160, the N3IN 210, UPF 99-1, AMF 99-2, SMF 99-3, and other control plane / user plane (CP / UP) functions 650.

[0103] The signaling is as follows. The prerequisite is that there is signaling for IPsec SA for NAS signaling between the UE 10, non-3GPP AP 160, and the N3IN 210.

[0104] 1. The UE has registered with 5GC over non-3GPP access via N3IN (e.g., via N3IWF or TNGF or W-AGF). The UE should send a PDU Session Establishment Request message to AMF as specified in step 1 of clause 4.3.2.2.1 of TS 23.502. This message should be sent to N3IN via the IPsec SA for NAS signaling (established as specified in clause 4.12.2 of 3GPP TS 23.502) and the N3IN should transparently forward the message to AMF in the 5GC.

[0105] 2a. Steps 2-11 specified in clause 4.3.2.2.1 of 3GPP TS 23.502 are executed according to the PDU Session Establishment procedure over 3GPP access. In the case of home-routed roaming, steps 2- 14 specified in clause 3GPP TS 23.502 4.3.2.2.2 are executed according to the PDU Session Establishment procedure over 3GPP access.

[0106] Along with the QoS related parameters, UPF’s L4S indication should be sent from SMF to AMF. This forms part of the implicit trigger 610.

[0107] 2b. The AMF should send a N2 PDU Session Request message to N3IWF to establish the access resources for this PDU Session. AMF should include UPF’s L4S indication in the N2 message to N3IN. This forms part of the implicit trigger 610.

[0108] 3. Creation of IPSec SAs for L4S specific flow.

[0109] 4a. The N3IN send to the UE an IKE Create Child SA request according to the IKEv2 specification in (IETF) RFC 7296 to establish the first IPsec Child SA for the L4S specific PDU Session. Along with the existing parameters (4a of Figure 4.12.5-1 of 3GPP TS 23.502), N3IN should include its L4S indication in the request.

[0110] One option is an explicit trigger 620, where the SMF indicates N3IN (using N2) to notify ECN- Decap-Support for the UPF-N3IN DL tunnel, and the SMF indicates UE (using NAS) to notify ECN-Decap-Support the N3IN-UE DL tunnel. 4b. If the UE accepts the new IPsec Child SA, the UE sends an IKE Create Child SA response according to the IKEv2 specification in RFC 7296. The UE should send the ECN-Decap-Support indication in the response message.

[0111] 5. After all IPsec Child SAs are established, the N3IN should forward to UE via the signaling IPsec SA (see clause 4.12.2.2 of 3GPP TS 23.502) the PDU Session Establishment Accept message received in step 2b.

[0112] 6. The N3IN should send to UPF its ECN-Decap-Support indication for the tunnel packets received from UPF either in.

[0113] Steps 6a, 6b: The ECN-Decap-Support indication should be sent to UPF via AMF to SMF (using Nsmf_PDUSessionUpdateSMContext) and then SMF to UPF (N4 message) or

[0114] Step 6: directly from N3IN to UPF Using GTP-U header information.

[0115] Note: The trigger to send the ECN-Decap-Support Indication (from UE to N3IN in step 4 and / or from N3IN to SMF / UPF in step 6) can happen in two ways:

[0116] (i) Implicit: As soon as UE (step 4a) or N3IN (step 2b) receives the L4S indication for the N3IN- to-UE tunnel and / or the UPF-to-N3IN tunnels, respectively, they can send the ECN-Decap- Support Indication (for the UE, step 4b, and for the N3IN step 6a, which also goes via 6b);

[0117] (ii) Explicit (shown partly in dotted box and step 6 in FIG. 6): The SMF 99-3 may send (620) explicit instruction to egress node (e.g., UE or N3IN) to send ECN-Decap-Support to the ingress node. For example, SMF can instruct N3IN to send report to UPF (for UPF-to-N3IN tunnel) and it can send NAS instruction to UE to send ECN-Decap-Support to N3IN (for the N3IN-to-UE tunnel). The explicit indication flows through step 6 from the N3IN to the UPF.

[0118] 7. Step 7 of Figure 4.12.5-1 of TS 23.502.

[0119] 8a. Step 8 of Figure 4.12.5-1 of TS 23.502 with following enhancements (see block 630): If UPF has received ECN-Decap-Support = Yes, it should create a rule to encapsulate the ECN markings (if received) from inner to outer IP layer.

[0120] If ECN-Decap-Support = No, then i) Do not encapsulate the ECN markings (if received) from inner to outer IP layer, (ii) use classic congestion control mechanism (e.g., drop packets in case of congestion).

[0121] 8b. Step 8 of Figure 4.12.5-1 of TS 23.502 with following enhancements (see block 640):

[0122] If N3IN has received ECN-Decap-Support = Yes, the N3IN should create a rule to encapsulate the ECN markings (if received) from inner to outer IP layer.

[0123] If ECN-Decap-Support = No, then i) do not encapsulate the ECN markings (if received) from inner to outer IP layer, (ii) use classic congestion control mechanism (e.g., drop packets in case of congestion)

[0124] Uplink is described now. Everything is similar to what is in FIG. 6, except the following:

[0125] 1) The L4S traffic is in UL direction.

[0126] 2) ECN-Decap-Support Indication for the UL L4S QoS flow should be sent from N3IN to the UE (UE should perform UL congestion handling ECN rule accordingly) in the IKE Create Child SA request. Similarly, UPF should send the ECN-Decap-Support Indication to N3IN (N3IN should perform UL congestion handling ECN rule accordingly) in either GTP-U header information or via SMF and AMF using N4 and N2 signaling, respectively.

[0127] Turning to FIG. 7, this figure shows a block diagram of one possible and non-limiting example of a cellular network 1 that is connected to a user equipment (UE) 10. In FIG. 7, a user equipment (UE) 10 is in communication via link 79 with the N3IN 210. The UE 10, N3IN 210, core network 90, and data network 91 are assumed to be part of a network 100, which is both 3GPP (e.g., the core network 90 of the cellular network 1) and non-3GPP (at least the N3IN 210). Not shown is a non-3GPP AP between the UE 10 and the N3IN 210. A UE 10 is a wired or wireless communication device, such as a mobile device, that is configured to access the N3IN 210. The UE 10 is illustrated with one or more antennas 28. The UE 10 includes one or more processors 13, one or more memories 15, and other circuitry 16. The other circuitry 16 includes one or more receivers (Rx(s)) 17 and one or more transmiters (Tx(s)) 18. A program 12 is used to cause the UE 10 to perform the operations described herein. For a UE 10, the other circuitry 16 could include circuitry such as for user interface elements (not shown) like a display. The program 12 may be implemented via instructions stored in memory / memories 15 and executed by processor(s) 13, or by hardware such being implemented as part of the processor(s) or other hardware elements, or both.

[0128] The N3IN 210, as a network element of the cellular network 1, provides the UE 10 access (and therefore may be referred to as an access node) to cellular network 1 and subsequently to the data network 91 via the core network 90 (e.g., via a user plane function (UPF) of the core network 90). The N3IN 210 includes one or more processors 73, one or more memories 75, and other circuitry 76. The other circuitry 76 includes one or more receivers (Rx(s)) 77 and one or more transmiters (Tx(s)) 78. A program 72 is used to cause the N3IN 210 to perform the operations described herein. The program 72 may be implemented via instructions stored in memory / memories 75 and executed by processor(s) 73, or by hardware such being implemented as part of the processor(s) or other hardware elements, or both.

[0129] The cellular network 1 includes a core network 90, that may include core network functionality, and which provide connectivity via a link or links 81 with a data network 91, such as a telephone network and / or a data communications network (e.g., the Internet). The core network 90 includes one or more processors 93, one or more memories 95, and other circuitry 96. The other circuitry 96 includes one or more receivers (Rx(s)) 97 and one or more transmitters (Tx(s)) 98. A program 92 is used to cause the core network 90 to perform the operations described herein. The program 92 may be implemented via instructions stored in memory / memories 95 and executed by processor(s) 93, or by hardware such being implemented as part of the processor(s) or other hardware elements, or both.

[0130] Core network 90 functionality for 5G may include access and mobility management functionality that is provided by a network function 99 such as an access and mobility management function (AMF), session management functionality that is provided by a network function such as a session management function (SMF). Core network functionality for access and mobility management in an LTE (Long Term Evolution) network may be provided by an MME (Mobility Management Entity) and / or SGW (Serving Gateway) functionality, which routes data to the data network. Many others are possible, as illustrated by the examples in FIG. 7: UPF 99-1; AMF 99-2; SMF 99-3; MME; SGW; GMLC (Gateway Mobile Location Center); LMF (Location Management Eunction); UDM (Unified Data Management) / UDR (Unified Data Repository); NRF (Network Repository Function); and / or E-SMLC (Evolved Serving Mobile Location Center). These are merely exemplary core network functionality that may be provided by the core network 90, and note that both 5G and LTE core network functionality might be provided by the core network 90. The N3IN 210 is coupled via a link 31 to the core network 90.

[0131] In the data network 91, there is a computer-readable medium 94. The computer-readable medium 94 contains instructions that, when downloaded and installed into the memories 15, 75, or 95 of the corresponding UE 10, N3IN 210, and / or core network element(s) 90, and executed by processor(s) 13, 73, or 93, cause the respective device to perform corresponding actions described herein. The computer-readable medium 94 may be implemented in other forms, such as via a compact disc or memory stick.

[0132] The core network 90 could be a 5GC (5G core network). The core network 90 can implement or comprise multiple network functions (NF(s)) 99, and the program 92 may comprise one or more of the NFs 99. A 5G core network may use hardware such as memory and processors and a virtualization layer. It could be a single standalone computing system, a distributed computing system, or a cloud computing system. The NFs 99, as network elements, of the core network could be containers or virtual machines running on the hardware of the computing system(s) making up the core network 90.

[0133] Block 2 illustrates that the core network 90 has a set of resources including 92, 93, 95, and 96. The individual NFs 99, such as the UPF 99-1, or the AMF 99-2, or the SMF 99-3, can be implemented via a corresponding subset 2’ of resources comprising 92’, 93’, 95’, and 96’. Regardless of how the individual NFs 99 are implemented, such as via a virtualization layer on top of the subset 2’ of resources, the NFs 99 are implemented via circuitry like the processors 93’, memories 95’, and other circuitry 96’, and the virtualization layer can be part or all of the program 92’.

[0134] The UPF is a network function that plays a role in data transfer. It interconnects the Data Network (DN) in the 5G architecture. The UPF 99-1 is also responsible for packet routing and forwarding, packet inspections, QoS (Quality of Service) handling, and an anchor point for intra and inter-RAT mobility. The AMF 99-2 receives all connection and session related information from the User Equipment (UE) (using the N1 / N2 reference points), and is responsible for handling connection and mobility management tasks. The SMF 99-3 is a 5G core component that performs a fundamental role in the 5G Service-Based Architecture (SBA). The SMF is primarily responsible for interacting with the decoupled data plane, creating, updating and removing Protocol Data Unit (PDU) sessions and managing session context with the User Plane Function (UPF).

[0135] The programs 12, 72, and 92 contain instructions (as part of a corresponding program 12, 72, and 92) stored by corresponding one or more memories 15, 75, or 95. These instructions, when executed by the corresponding one or more processors 13, 73, or 93, cause the corresponding apparatus 10, 210, or 90, to perform the operations described herein. The computer readable memories 15, 75, or 95 are circuitry and may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, firmware, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The computer readable memories 15, 75, and 95 may be means for performing storage functions. The processors 13, 73, and 93, are circuitry and may be of any type suitable to the local technical environment. For example, these processors may include one or more of general -purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), processors based on a multi-core processor architecture, and may also include specialized circuits such as field-programmable gate arrays (FPGAs), application specific circuits (ASICs), signal processing devices and other devices, or combinations of these devices, as non-limiting examples. The processors 13, 73, and 93 are circuitry that can be programmed to perform functions via software, firmware or the like (including microcode), but are not solely software. The processors 13, 73, and 93 may be means for causing their respective apparatus to perform functions, such as those described herein. Particularly, for any apparatus having means to perform functions described herein, the means may include at least one processor, and at least one memory storing instructions that, when executed by at least one processor, cause the performance of the apparatus.

[0136] The receivers 17, 77, and 97, and the transmitters 18, 78, and 98 may implement wired or wireless interfaces. The receivers and transmitters may be grouped together as transceivers.

[0137] The cellular network 1 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as either external, combining many networks, or parts of networks, into a virtual unit, or internal, providing network-like functionality to software containers on a single system. Note that the virtualized entities (such as network functions 99) that result from the network virtualization are still implemented, at some level, using hardware such as processors 73 and / or 93 and memories 75 and / or 95, and also such virtualized entities create technical effects.

[0138] In general, the various embodiments of the user equipment 10 can include, but are not limited to, cellular telephones (such as smart phones, mobile phones, cellular phones, voice over Internet Protocol (IP) (VoIP) phones, and / or wireless local loop phones), tablets, portable computers, vehicles or vehicle-mounted devices for, e.g., wireless V2X (vehicle-to-everything) communication, image capture devices such as digital cameras, gaming devices, music storage and playback appliances, Internet appliances (including Internet of Things, loT, devices), loT devices with sensors and / or actuators for, e.g., automation applications, as well as portable units or terminals that incorporate combinations of such functions, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), Universal Serial Bus (USB) dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. That is, the UE 10 could be any end device that may be capable of wireless communication. By way of example rather than limitation, the UE may also be referred to as a communication device, terminal device (MT), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT).

[0139] The following are additional examples.

[0140] Example 1. A method, comprising: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between the user plane function and a user equipment, determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non- 3 GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user plane function, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user plane function comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets have encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user equipment supports decapsulation for explicit congestion notification; and performing one of the following: based on the user equipment supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user equipment over a second tunnel between the non-3GPP intermediate network entity and the user equipment, the one or more packets with the explicit congestion notification markings; or based on the user equipment not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0141] Example 2. The method according to example 1, wherein: determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises: determining by the non-3GPP intermediate network entity to send the indication implicitly based on receiving L4S (Low Latency Low Loss Scalable throughput) indication from the user plane function; and the sending the indication comprises sending, in response to receiving the L4S indication and by the non-3GPP intermediate network entity, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification.

[0142] Example 3. The method according to example 1, wherein: determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises: receiving, by the non-3GPP intermediate network entity, explicit indication by a 5G network function to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; and the sending the indication comprises sending, in response to receiving the explicit indication, sending the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification. Example 4. The method according to example 2 or 3, wherein the sending, in response to receiving the L4S (Low Latency Low Loss Scalable throughput) indication and by the non-3GPP intermediate network entity, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification is performed either via session management function to the user plane function or directly to the user plane function using GTP-U header information.

[0143] Example 5. The method according to any of examples 1 to 4, wherein: the determining whether the user equipment supports decapsulation for explicit congestion notification determines the user equipment supports decapsulation based on receiving by the non-3GPP intermediate network entity an indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification; and the sending the one or more packets with the explicit congestion notification markings is performed in response to the indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification.

[0144] Example 6. The method according to example 5, wherein the sending the one or more packets with the explicit congestion notification markings using Layer 2 quality of service mechanisms to classify L4S (Low Latency Low Loss Scalable throughput) traffic having the explicit congestion notification markings.

[0145] Example 7. The method according to example 5 or 6, wherein: the sending the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises sending an indication along with indication of supported L2 quality of service fields via user-plane signaling; and the method further comprises receiving, by the non-3GPP intermediate network entity, explicit congestion notification field information having L2 quality of service fields in the flow that match the supported L2 quality of service fields.

[0146] Example 8. The method according to any of examples 1 to 4, wherein: the determining whether the user equipment supports decapsulation for explicit congestion notification determines the user equipment does not support decapsulation in response to the non-3GPP intermediate network entity not receiving an indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification; and addressing, by the non-3GPP intermediate network entity, the congestion via one or more mechanisms. Example 9. The method according to example 8, wherein the one or more mechanisms comprise dropping one or more packets to address the congestion.

[0147] Example 10. The method according to example 8, wherein the one or more mechanisms comprise sending, by the non-3GPP intermediate network entity to the user equipment over the second tunnel, the one or more packets without the explicit congestion notification markings.

[0148] Example 11. The method according to any of examples 1 to 10, wherein the non-3GPP intermediate network entity comprises one of the following: a N3IWF; a TNGF; or a W-AGF.

[0149] Example 12. A method, comprising: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, determining, by the user plane function, whether the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function using explicit congestion notification markings in one or more packets received for forwarding to the non-3GPP intermediate network entity, that congestion was experienced; performing one of the following: based on a determination the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification, sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings; or based on a determination the non-3GPP intermediate network entity does not support decapsulation for explicit congestion notification, addressing by the user plane function the congestion via one or more mechanisms.

[0150] Example 13. The method according to example 12, further comprising, based on the determination the user plane function does not support decapsulation for explicit congestion notification, addressing, by the user plane function, the congestion via one or more mechanisms.

[0151] Example 14. The method according to example 13, wherein the one or more mechanisms comprises dropping the one or more packets to address the congestion.

[0152] Example 15. The method according to example 13, wherein the one or more mechanisms comprises sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets without the explicit congestion notification markings. Example 16. The method according to example 12, wherein: the method further comprises receiving, by the user plane function, indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function, the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification based on the receiving the indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; and sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings.

[0153] Example 17. The method according to example 16, wherein the receiving the indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises receiving the indication that the non- 3 GPP intermediate network entity supports decapsulation for explicit congestion notification for the non-3GPP intermediate network entity from the non-3GPP intermediate network entity or from an session management function.

[0154] Example 18. The method according to any of examples 12 to 17, wherein the non-3GPP intermediate network entity comprises one of the following: a N3IWF; a TNGF; or a W-AGF.

[0155] Example 19. A method, comprising: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending indication, by the user equipment to the non-3GPP intermediate network entity, that the user equipment supports decapsulation for explicit congestion notification; receiving, by the user equipment, one or more packets over a tunnel from the user equipment to the non-3GPP intermediate network entity, the one or more packets comprising at least explicit congestion notification markings; decapsulating, by the user equipment, the one or more packets; determining, by the user equipment using the decapsulated one or more packets, that congestion has occurred in the tunnel; and sending, by the user equipment toward an application to which the one or more packets are directed, indication that congestion has occurred.

[0156] Example 20. A method, comprising: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between a user equipment and a user plane function, determining by the non-3GPP intermediate network entity to send indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user equipment, the indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user equipment comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets has encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user plane function supports decapsulation for explicit congestion notification; and performing one of the following: based on the user plane function supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user plane function over a second tunnel between the non-3GPP intermediate network entity and the user plane function, the one or more packets with the explicit congestion notification markings; or based on the user plane function not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0157] Example 21. A method, comprising: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending, by the user plane function to the non-3GPP intermediate network entity, indication that the user plane function supports decapsulation for explicit congestion notification; receiving, by the user plane function from the non-3GPP intermediate network entity, one or more packets having explicit congestion notification markings; performing, by the user plane function, decapsulation of the one or more packets to determine that the explicit congestion notification markings are in the one or more packets; and sending, by the user plane function toward a destination, the one or more packets with markings indicating congestion has occurred.

[0158] Example 22. A method, comprising: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, receiving indication, by the user equipment from the non-3GPP intermediate network entity, that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user equipment, congestion has occurred for one or more packets; and sending, by the user equipment toward the non-3GPP intermediate network entity, the one or more packets that are marked with explicit congestion notification markings.

[0159] Example 23. An apparatus, comprising means for: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between the user plane function and a user equipment, determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user plane function, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non- 3 GPP intermediate network entity from the user plane function comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets have encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user equipment supports decapsulation for explicit congestion notification; and performing one of the following: based on the user equipment supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user equipment over a second tunnel between the non-3GPP intermediate network entity and the user equipment, the one or more packets with the explicit congestion notification markings; or based on the user equipment not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0160] Example 24. The apparatus according to example 23, wherein: determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises: determining by the non-3GPP intermediate network entity to send the indication implicitly based on receiving L4S (Low Latency Low Loss Scalable throughput) indication from the user plane function; and the sending the indication comprises sending, in response to receiving the L4S indication and by the non-3GPP intermediate network entity, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification.

[0161] Example 25. The apparatus according to example 23, wherein: determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises: receiving, by the non-3GPP intermediate network entity, explicit indication by a 5G network function to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; and the sending the indication comprises sending, in response to receiving the explicit indication, sending the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification.

[0162] Example 26. The apparatus according to example 24 or 25, wherein the sending, in response to receiving the L4S (Low Latency Low Loss Scalable throughput) indication and by the non-3GPP intermediate network entity, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification is performed either via session management function to the user plane function or directly to the user plane function using GTP-U header information.

[0163] Example 27. The apparatus according to any of examples 23 to 26, wherein: the determining whether the user equipment supports decapsulation for explicit congestion notification determines the user equipment supports decapsulation based on receiving by the non-3GPP intermediate network entity an indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification; and the sending the one or more packets with the explicit congestion notification markings is performed in response to the indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification.

[0164] Example 28. The apparatus according to example 27, wherein the sending the one or more packets with the explicit congestion notification markings using Layer 2 quality of service mechanisms to classify L4S (Low Latency Low Loss Scalable throughput) traffic having the explicit congestion notification markings. Example 29. The apparatus according to example 27 or 28, wherein: the sending the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises sending an indication along with indication of supported L2 quality of service fields via user-plane signaling; and the means are further configured for receiving, by the non-3GPP intermediate network entity, explicit congestion notification field information having L2 quality of service fields in the flow that match the supported L2 quality of service fields.

[0165] Example 30. The apparatus according to any of examples 23 to 26, wherein: the determining whether the user equipment supports decapsulation for explicit congestion notification determines the user equipment does not support decapsulation in response to the non-3GPP intermediate network entity not receiving an indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification; and addressing, by the non-3GPP intermediate network entity, the congestion via one or more mechanisms.

[0166] Example 31. The apparatus according to example 30, wherein the one or more mechanisms comprise dropping one or more packets to address the congestion.

[0167] Example 32. The apparatus according to example 30, wherein the one or more mechanisms comprise sending, by the non-3GPP intermediate network entity to the user equipment over the second tunnel, the one or more packets without the explicit congestion notification markings.

[0168] Example 33. The apparatus according to any of examples 23 to 32, wherein the non-3GPP intermediate network entity comprises one of the following: a N3IWF; a TNGF; or a W-AGF.

[0169] Example 34. An apparatus, comprising means for: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, determining, by the user plane function, whether the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function using explicit congestion notification markings in one or more packets received for forwarding to the non-3GPP intermediate network entity, that congestion was experienced; performing one of the following: based on a determination the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification, sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings; or based on a determination the non-3GPP intermediate network entity does not support decapsulation for explicit congestion notification, addressing by the user plane function the congestion via one or more mechanisms.

[0170] Example 35. The apparatus according to example 34, wherein the means are further configured for, based on the determination the user plane function does not support decapsulation for explicit congestion notification, addressing, by the user plane function, the congestion via one or more mechanisms.

[0171] Example 36. The apparatus according to example 35, wherein the one or more mechanisms comprises dropping the one or more packets to address the congestion.

[0172] Example 37. The apparatus according to example 35, wherein the one or more mechanisms comprises sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets without the explicit congestion notification markings.

[0173] Example 38. The apparatus according to example 34, wherein: the means are further configured for receiving, by the user plane function, indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function, the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification based on the receiving the indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; and sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings.

[0174] Example 39. The apparatus according to example 38, wherein the receiving the indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises receiving the indication that the non- 3 GPP intermediate network entity supports decapsulation for explicit congestion notification for the non-3GPP intermediate network entity from the non-3GPP intermediate network entity or from an session management function. Example 40. The apparatus according to any of examples 34 to 39, wherein the non-3GPP intermediate network entity comprises one of the following: a N3IWF; a TNGF; or a W-AGF.

[0175] Example 41. An apparatus, comprising means for: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending indication, by the user equipment to the non-3GPP intermediate network entity, that the user equipment supports decapsulation for explicit congestion notification; receiving, by the user equipment, one or more packets over a tunnel from the user equipment to the non-3GPP intermediate network entity, the one or more packets comprising at least explicit congestion notification markings; decapsulating, by the user equipment, the one or more packets; determining, by the user equipment using the decapsulated one or more packets, that congestion has occurred in the tunnel; and sending, by the user equipment toward an application to which the one or more packets are directed, indication that congestion has occurred.

[0176] Example 42. An apparatus, comprising means for: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between a user equipment and a user plane function, determining by the non-3GPP intermediate network entity to send indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user equipment, the indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user equipment comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets has encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user plane function supports decapsulation for explicit congestion notification; and performing one of the following: based on the user plane function supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user plane function over a second tunnel between the non-3GPP intermediate network entity and the user plane function, the one or more packets with the explicit congestion notification markings; or based on the user plane function not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0177] Example 43. An apparatus, comprising means for: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending, by the user plane function to the non-3GPP intermediate network entity, indication that the user plane function supports decapsulation for explicit congestion notification; receiving, by the user plane function from the non-3GPP intermediate network entity, one or more packets having explicit congestion notification markings; performing, by the user plane function, decapsulation of the one or more packets to determine that the explicit congestion notification markings are in the one or more packets; and sending, by the user plane function toward a destination, the one or more packets with markings indicating congestion has occurred.

[0178] Example 44. An apparatus, comprising means for: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, receiving indication, by the user equipment from the non-3GPP intermediate network entity, that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user equipment, congestion has occurred for one or more packets; and sending, by the user equipment toward the non-3GPP intermediate network entity, the one or more packets that are marked with explicit congestion notification markings.

[0179] Example 45. The apparatus of any preceding apparatus example, wherein the means comprises: at least one processor; and at least one memory storing instructions that, when executed by at least one processor, cause the performance of the apparatus.

[0180] Example 46. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between the user plane function and a user equipment, determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user plane function, the indication to the user plane function that the non- 3 GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user plane function comprise at least encapsulated explicit congestion notification markings; determining, by the non- 3 GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets have encapsulated explicit congestion notification markings; determining, by the non- 3 GPP intermediate network entity, whether the user equipment supports decapsulation for explicit congestion notification; and performing one of the following: based on the user equipment supporting decapsulation and determining that congestion was experienced, sending, by the non- 3 GPP intermediate network entity to the user equipment over a second tunnel between the non- 3 GPP intermediate network entity and the user equipment, the one or more packets with the explicit congestion notification markings; or based on the user equipment not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0181] Example 47. The apparatus according to example 46, wherein: determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises: determining by the non-3GPP intermediate network entity to send the indication implicitly based on receiving L4S (Low Latency Low Loss Scalable throughput) indication from the user plane function; and the sending the indication comprises sending, in response to receiving the L4S indication and by the non-3GPP intermediate network entity, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification.

[0182] Example 48. The apparatus according to example 46, wherein: determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises: receiving, by the non-3GPP intermediate network entity, explicit indication by a 5G network function to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; and the sending the indication comprises sending, in response to receiving the explicit indication, sending the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification. Example 49. The apparatus according to example 47 or 48, wherein the sending, in response to receiving the L4S (Low Latency Low Loss Scalable throughput) indication and by the non-3GPP intermediate network entity, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification is performed either via session management function to the user plane function or directly to the user plane function using GTP-U header information.

[0183] Example 50. The apparatus according to any of examples 46 to 49, wherein: the determining whether the user equipment supports decapsulation for explicit congestion notification determines the user equipment supports decapsulation based on receiving by the non-3GPP intermediate network entity an indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification; and the sending the one or more packets with the explicit congestion notification markings is performed in response to the indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification.

[0184] Example 51. The apparatus according to example 50, wherein the sending the one or more packets with the explicit congestion notification markings using Layer 2 quality of service mechanisms to classify L4S (Low Latency Low Loss Scalable throughput) traffic having the explicit congestion notification markings.

[0185] Example 52. The apparatus according to example 50 or 51, wherein: the sending the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises sending an indication along with indication of supported L2 quality of service fields via user-plane signaling; and the one or more memories further store instructions that, when executed by the one or more processors, cause the apparatus at least to perform receiving, by the non-3GPP intermediate network entity, explicit congestion notification field information having L2 quality of service fields in the flow that match the supported L2 quality of service fields.

[0186] Example 53. The apparatus according to any of examples 46 to 49, wherein: the determining whether the user equipment supports decapsulation for explicit congestion notification determines the user equipment does not support decapsulation in response to the non-3GPP intermediate network entity not receiving an indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification; and addressing, by the non-3GPP intermediate network entity, the congestion via one or more mechanisms.

[0187] Example 54. The apparatus according to example 53, wherein the one or more mechanisms comprise dropping one or more packets to address the congestion.

[0188] Example 55. The apparatus according to example 53, wherein the one or more mechanisms comprise sending, by the non-3GPP intermediate network entity to the user equipment over the second tunnel, the one or more packets without the explicit congestion notification markings.

[0189] Example 56. The apparatus according to any of examples 46 to 55, wherein the non-3GPP intermediate network entity comprises one of the following: a N3IWF; a TNGF; or a W-AGF.

[0190] Example 57. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, determining, by the user plane function, whether the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function using explicit congestion notification markings in one or more packets received for forwarding to the non-3GPP intermediate network entity, that congestion was experienced; performing one of the following: based on a determination the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification, sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings; or based on a determination the non-3GPP intermediate network entity does not support decapsulation for explicit congestion notification, addressing by the user plane function the congestion via one or more mechanisms.

[0191] Example 58. The apparatus according to example 57, wherein the one or more memories further store instructions that, when executed by the one or more processors, cause the apparatus at least to perform, based on the determination the user plane function does not support decapsulation for explicit congestion notification, addressing, by the user plane function, the congestion via one or more mechanisms. Example 59. The apparatus according to example 58, wherein the one or more mechanisms comprises dropping the one or more packets to address the congestion.

[0192] Example 60. The apparatus according to example 58, wherein the one or more mechanisms comprises sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets without the explicit congestion notification markings.

[0193] Example 61. The apparatus according to example 57, wherein: the one or more memories further store instructions that, when executed by the one or more processors, cause the apparatus at least to perform receiving, by the user plane function, indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function, the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification based on the receiving the indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; and sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings.

[0194] Example 62. The apparatus according to example 61, wherein the receiving the indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises receiving the indication that the non- 3 GPP intermediate network entity supports decapsulation for explicit congestion notification for the non-3GPP intermediate network entity from the non-3GPP intermediate network entity or from an session management function.

[0195] Example 63. The apparatus according to any of examples 57 to 62, wherein the non-3GPP intermediate network entity comprises one of the following: a N3IWF; a TNGF; or a W-AGF.

[0196] Example 64. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a user equipment connected to a non-third generation partnership project (non- 3 GPP) intermediate network entity, sending indication, by the user equipment to the non-3GPP intermediate network entity, that the user equipment supports decapsulation for explicit congestion notification; receiving, by the user equipment, one or more packets over a tunnel from the user equipment to the non-3GPP intermediate network entity, the one or more packets comprising at least explicit congestion notification markings; decapsulating, by the user equipment, the one or more packets; determining, by the user equipment using the decapsulated one or more packets, that congestion has occurred in the tunnel; and sending, by the user equipment toward an application to which the one or more packets are directed, indication that congestion has occurred.

[0197] Example 65. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between a user equipment and a user plane function, determining by the non-3GPP intermediate network entity to send indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user equipment, the indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user equipment comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets has encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user plane function supports decapsulation for explicit congestion notification; and performing one of the following: based on the user plane function supporting decapsulation and determining that congestion was experienced, sending, by the non- 3 GPP intermediate network entity to the user plane function over a second tunnel between the non- 3 GPP intermediate network entity and the user plane function, the one or more packets with the explicit congestion notification markings; or based on the user plane function not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

[0198] Example 66. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending, by the user plane function to the non-3GPP intermediate network entity, indication that the user plane function supports decapsulation for explicit congestion notification; receiving, by the user plane function from the non-3GPP intermediate network entity, one or more packets having explicit congestion notification markings; performing, by the user plane function, decapsulation of the one or more packets to determine that the explicit congestion notification markings are in the one or more packets; and sending, by the user plane function toward a destination, the one or more packets with markings indicating congestion has occurred.

[0199] Example 67. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a user equipment connected to a non-third generation partnership project (non- 3 GPP) intermediate network entity, receiving indication, by the user equipment from the non- 3 GPP intermediate network entity, that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user equipment, congestion has occurred for one or more packets; and sending, by the user equipment toward the non-3GPP intermediate network entity, the one or more packets that are marked with explicit congestion notification markings.

[0200] Example 68. A computer program, comprising instructions for performing the methods of any of examples 1 to 22, when the computer program is run on an apparatus.

[0201] Example 69. The computer program according to example 68, wherein the computer program is a computer program product comprising a computer-readable medium bearing instructions embodied therein for use with the apparatus.

[0202] Example 70. The computer program according to example 68, wherein the computer program is directly loadable into an internal memory of the apparatus.

[0203] As used in this application, the term “circuitry” may refer to one or more or all of the following:

[0204] (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and

[0205] (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

[0206] (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0207] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0208] Embodiments herein may be implemented in software (executed by one or more processors), hardware (e.g., an application specific integrated circuit), or a combination of software and hardware. In an example embodiment, the software (e.g., application logic, an instruction set) is maintained on any one of various conventional computer-readable media. In the context of this document, a “computer-readable medium” may be any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer, with one example of a computer described and depicted, e.g., in FIG. 7. A computer-readable medium may comprise a computer- readable storage medium (e.g., memories 15, 75, and 95 or other device) that may be any media or means that can contain, store, and / or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer. A computer-readable storage medium does not comprise propagating signals, and therefore may be considered to be non-transitory. The term “non-transitory”, as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM, random access memory, versus ROM, read-only memory).

[0209] If desired, the different functions discussed herein may be performed in a different order and / or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined. Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments and / or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

[0210] It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims.

[0211] The following abbreviations that may be found in the specification and / or the drawing figures are defined as follows:

[0212] 3 GPP third generation partnership project

[0213] 5G fifth generation

[0214] AF application function

[0215] AMF access and mobility management function

[0216] AP access point

[0217] API application programming interface

[0218] App application

[0219] CE Congestion Experienced

[0220] CP / UP control plane / user plane

[0221] Decap decapsulation or decapsulating

[0222] DEI Discard Eligibility Indicator

[0223] DSCP differentiated services code point

[0224] E2E end-to-end

[0225] Encap encapsulation or encapsulating

[0226] ECN Explicit Congestion Notification

[0227] E-SMLC evolved serving mobile location center eNB (or eNodeB) evolved Node B (e.g., an LTE base station)

[0228] GMLC Gateway Mobile Location Center

[0229] GPRS General Packet Radio Service gNB (or gNodeB) base station for 5G / NR

[0230] GRE Generic Routing Encapsulation

[0231] GTP-U GPRS Tunneling Protocol in User Plane ID or Id identifier

[0232] IETF Internet Engineering Task Force

[0233] I / F interface

[0234] IK Internet Key Exchange Protocol

[0235] IP internet protocol

[0236] IPSec or IPsec Internet Protocol Security

[0237] KI key issue

[0238] L2 layer 2

[0239] L4S Low Latency Low Loss Scalable throughput

[0240] LMF Location Management Function

[0241] LIE long term evolution

[0242] MAC medium access control

[0243] MME mobility management entity

[0244] NAS Non-access stratum

[0245] N3IWF Non-3GPP Inter-Working Function

[0246] N3IN non-3GPP Intermediate access node: N3IWF, TNGF or W-AGF

[0247] NF network function ng or NG next generation

[0248] NR new radio

[0249] NRF Network Repository Function

[0250] N / W or NW network

[0251] NWt a trusted reference point between the UE and TNGF

[0252] NWu an untrusted reference point between the UE and N3IWF

[0253] PCP priority code point

[0254] PHY physical layer

[0255] PSA PDU (protocol data unit) Session Anchor

[0256] QoE quality of experience

[0257] QoS quality of service

[0258] RAN radio access network

[0259] Rel. release

[0260] RFC Request For Comment

[0261] Rx receiver

[0262] SA security association SA2 3GPP TSG SA WG2, 3GPP Technical Specification Group Service and System Aspects, working group 2

[0263] SGW serving gateway

[0264] SMF session management function TCP transmission control protocol

[0265] TNGF Trusted Non-3GPP Gateway Function

[0266] TRP transmission-reception point

[0267] Tx transmitter

[0268] UDM unified data management LDP User datagram protocol

[0269] UDR unified data repository

[0270] UE user equipment (e.g., a wireless, typically mobile device)

[0271] UPF user plane function

[0272] VLAN virtual local area network W-AGF Wireline Access Gateway Function

[0273] WLAN wireless local area network XR extended reality XRM Extended Reality and Media service

Claims

Claims:

1. A method, comprising: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between the user plane function and a user equipment, determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user plane function, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user plane function comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets have encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user equipment supports decapsulation for explicit congestion notification; and performing one of the following: based on the user equipment supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user equipment over a second tunnel between the non- 3 GPP intermediate network entity and the user equipment, the one or more packets with the explicit congestion notification markings; or based on the user equipment not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

2. The method according to claim 1, wherein: determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises: determining by the non-3GPP intermediate network entity to send the indication implicitly based on receiving L4S (Low Latency Low Loss Scalable throughput) indication from the user plane function; and the sending the indication comprises sending, in response to receiving the L4S indication and by the non-3GPP intermediate network entity, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification.

3. The method according to claim 1, wherein: determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises: receiving, by the non-3GPP intermediate network entity, explicit indication by a 5G network function to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; and the sending the indication comprises sending, in response to receiving the explicit indication, sending the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification.

4. The method according to claim 2 or 3, wherein the sending, in response to receiving the L4S (Low Latency Low Loss Scalable throughput) indication and by the non-3GPP intermediate network entity, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification is performed either via session management function to the user plane function or directly to the user plane function using GTP-U header information.

5. The method according to any of claims 1 to 4, wherein: the determining whether the user equipment supports decapsulation for explicit congestion notification determines the user equipment supports decapsulation based on receiving by the non-3GPP intermediate network entity an indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification; and the sending the one or more packets with the explicit congestion notification markings is performed in response to the indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification.

6. The method according to claim 5, wherein the sending the one or more packets with the explicit congestion notification markings using Layer 2 quality of service mechanisms to classify L4S (Low Latency Low Loss Scalable throughput) traffic having the explicit congestion notification markings.

7. The method according to claim 5 or 6, wherein: the sending the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises sending an indication along with indication of supported L2 quality of service fields via user-plane signaling; and the method further comprises receiving, by the non-3GPP intermediate network entity, explicit congestion notification field information having L2 quality of service fields in the flow that match the supported L2 quality of service fields.

8. The method according to any of claims 1 to 4, wherein: the determining whether the user equipment supports decapsulation for explicit congestion notification determines the user equipment does not support decapsulation in response to the non-3GPP intermediate network entity not receiving an indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification; and addressing, by the non-3GPP intermediate network entity, the congestion via one or more mechanisms.

9. The method according to claim 8, wherein the one or more mechanisms comprise dropping one or more packets to address the congestion.

10. The method according to claim 8, wherein the one or more mechanisms comprise sending, by the non-3GPP intermediate network entity to the user equipment over the second tunnel, the one or more packets without the explicit congestion notification markings.

11. The method according to any of claims 1 to 10, wherein the non-3GPP intermediate network entity comprises one of the following: a N3IWF; a TNGF; or a W-AGF.

12. A method, comprising: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, determining, by the user plane function, whether the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function using explicit congestion notification markings in one or more packets received for forwarding to the non-3GPP intermediate network entity, that congestion was experienced; performing one of the following: based on a determination the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification, sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings; or based on a determination the non-3GPP intermediate network entity does not support decapsulation for explicit congestion notification, addressing by the user plane function the congestion via one or more mechanisms.

13. The method according to claim 12, further comprising, based on the determination the user plane function does not support decapsulation for explicit congestion notification, addressing, by the user plane function, the congestion via one or more mechanisms.

14. The method according to claim 13, wherein the one or more mechanisms comprises dropping the one or more packets to address the congestion.

15. The method according to claim 13, wherein the one or more mechanisms comprises sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets without the explicit congestion notification markings.

16. The method according to claim 12, wherein: the method further comprises receiving, by the user plane function, indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function, the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification based on the receiving the indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; and sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings.

17. The method according to claim 16, wherein the receiving the indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises receiving the indication that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification for the non-3GPP intermediate network entity from the non-3GPP intermediate network entity or from an session management function.

18. The method according to any of claims 12 to 17, wherein the non-3GPP intermediate network entity comprises one of the following: a N3IWF; a TNGF; or a W-AGF.

19. A method, comprising: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending indication, by the user equipment to the non- 3 GPP intermediate network entity, that the user equipment supports decapsulation for explicit congestion notification; receiving, by the user equipment, one or more packets over a tunnel from the user equipment to the non-3GPP intermediate network entity, the one or more packets comprising at least explicit congestion notification markings;decapsulating, by the user equipment, the one or more packets; determining, by the user equipment using the decapsulated one or more packets, that congestion has occurred in the tunnel; and sending, by the user equipment toward an application to which the one or more packets are directed, indication that congestion has occurred.

20. A method, comprising: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between a user equipment and a user plane function, determining by the non-3GPP intermediate network entity to send indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user equipment, the indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user equipment comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets has encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user plane function supports decapsulation for explicit congestion notification; and performing one of the following: based on the user plane function supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user plane function over a second tunnel between the non-3GPP intermediate network entity and the user plane function, the one or more packets with the explicit congestion notification markings; orbased on the user plane function not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

21. A method, comprising: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending, by the user plane function to the non-3GPP intermediate network entity, indication that the user plane function supports decapsulation for explicit congestion notification; receiving, by the user plane function from the non-3GPP intermediate network entity, one or more packets having explicit congestion notification markings; performing, by the user plane function, decapsulation of the one or more packets to determine that the explicit congestion notification markings are in the one or more packets; and sending, by the user plane function toward a destination, the one or more packets with markings indicating congestion has occurred.

22. A method, comprising: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, receiving indication, by the user equipment from the non-3GPP intermediate network entity, that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user equipment, congestion has occurred for one or more packets; and sending, by the user equipment toward the non-3GPP intermediate network entity, the one or more packets that are marked with explicit congestion notification markings.

23. An apparatus, comprising means for: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between the user plane function and a user equipment, determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification;sending, by the non-3GPP intermediate network entity to the user plane function, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user plane function comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets have encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user equipment supports decapsulation for explicit congestion notification; and performing one of the following: based on the user equipment supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user equipment over a second tunnel between the non- 3 GPP intermediate network entity and the user equipment, the one or more packets with the explicit congestion notification markings; or based on the user equipment not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

24. The apparatus according to claim 23, wherein: determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises: determining by the non-3GPP intermediate network entity to send the indication implicitly based on receiving L4S (Low Latency Low Loss Scalable throughput) indication from the user plane function; and the sending the indication comprises sending, in response to receiving the L4S indication and by the non-3GPP intermediate network entity, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification.

25. The apparatus according to claim 23, wherein: determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises: receiving, by the non-3GPP intermediate network entity, explicit indication by a 5G network function to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; and the sending the indication comprises sending, in response to receiving the explicit indication, sending the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification.

26. The apparatus according to claim 24 or 25, wherein the sending, in response to receiving the L4S (Low Latency Low Loss Scalable throughput) indication and by the non-3GPP intermediate network entity, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification is performed either via session management function to the user plane function or directly to the user plane function using GTP-U header information.

27. The apparatus according to any of claims 23 to 26, wherein: the determining whether the user equipment supports decapsulation for explicit congestion notification determines the user equipment supports decapsulation based on receiving by the non-3GPP intermediate network entity an indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification; and the sending the one or more packets with the explicit congestion notification markings is performed in response to the indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification.

28. The apparatus according to claim 27, wherein the sending the one or more packets with the explicit congestion notification markings using Layer 2 quality of service mechanisms toclassify L4S (Low Latency Low Loss Scalable throughput) traffic having the explicit congestion notification markings.

29. The apparatus according to claim 27 or 28, wherein: the sending the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises sending an indication along with indication of supported L2 quality of service fields via user-plane signaling; and the means are further configured for receiving, by the non-3GPP intermediate network entity, explicit congestion notification field information having L2 quality of service fields in the flow that match the supported L2 quality of service fields.

30. The apparatus according to any of claims 23 to 26, wherein: the determining whether the user equipment supports decapsulation for explicit congestion notification determines the user equipment does not support decapsulation in response to the non-3GPP intermediate network entity not receiving an indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification; and addressing, by the non-3GPP intermediate network entity, the congestion via one or more mechanisms.

31. The apparatus according to claim 30, wherein the one or more mechanisms comprise dropping one or more packets to address the congestion.

32. The apparatus according to claim 30, wherein the one or more mechanisms comprise sending, by the non-3GPP intermediate network entity to the user equipment over the second tunnel, the one or more packets without the explicit congestion notification markings.

33. The apparatus according to any of claims 23 to 32, wherein the non-3GPP intermediate network entity comprises one of the following: a N3IWF; a TNGF; or a W-AGF.

34. An apparatus, comprising means for: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, determining, by the user plane function, whether the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function using explicit congestion notification markings in one or more packets received for forwarding to the non-3GPP intermediate network entity, that congestion was experienced; performing one of the following: based on a determination the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification, sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings; or based on a determination the non-3GPP intermediate network entity does not support decapsulation for explicit congestion notification, addressing by the user plane function the congestion via one or more mechanisms.

35. The apparatus according to claim 34, wherein the means are further configured for , based on the determination the user plane function does not support decapsulation for explicit congestion notification, addressing, by the user plane function, the congestion via one or more mechanisms.

36. The apparatus according to claim 35, wherein the one or more mechanisms comprises dropping the one or more packets to address the congestion.

37. The apparatus according to claim 35, wherein the one or more mechanisms comprises sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets without the explicit congestion notification markings.

38. The apparatus according to claim 34, wherein: the means are further configured for receiving, by the user plane function, indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification;determining, by the user plane function, the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification based on the receiving the indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; and sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings.

39. The apparatus according to claim 38, wherein the receiving the indication from the non- 3 GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises receiving the indication that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification for the non-3GPP intermediate network entity from the non-3GPP intermediate network entity or from an session management function.

40. The apparatus according to any of claims 34 to 39, wherein the non-3GPP intermediate network entity comprises one of the following: a N3IWF; a TNGF; or a W-AGF.

41. An apparatus, comprising means for: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending indication, by the user equipment to the non- 3 GPP intermediate network entity, that the user equipment supports decapsulation for explicit congestion notification; receiving, by the user equipment, one or more packets over a tunnel from the user equipment to the non-3GPP intermediate network entity, the one or more packets comprising at least explicit congestion notification markings; decapsulating, by the user equipment, the one or more packets; determining, by the user equipment using the decapsulated one or more packets, that congestion has occurred in the tunnel; and sending, by the user equipment toward an application to which the one or more packets are directed, indication that congestion has occurred.

42. An apparatus, comprising means for: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between a user equipment and a user plane function, determining by the non-3GPP intermediate network entity to send indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user equipment, the indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user equipment comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets has encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user plane function supports decapsulation for explicit congestion notification; and performing one of the following: based on the user plane function supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user plane function over a second tunnel between the non-3GPP intermediate network entity and the user plane function, the one or more packets with the explicit congestion notification markings; or based on the user plane function not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

43. An apparatus, comprising means for: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending, by the userplane function to the non-3GPP intermediate network entity, indication that the user plane function supports decapsulation for explicit congestion notification; receiving, by the user plane function from the non-3GPP intermediate network entity, one or more packets having explicit congestion notification markings; performing, by the user plane function, decapsulation of the one or more packets to determine that the explicit congestion notification markings are in the one or more packets; and sending, by the user plane function toward a destination, the one or more packets with markings indicating congestion has occurred.

44. An apparatus, comprising means for: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, receiving indication, by the user equipment from the non-3GPP intermediate network entity, that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user equipment, congestion has occurred for one or more packets; and sending, by the user equipment toward the non-3GPP intermediate network entity, the one or more packets that are marked with explicit congestion notification markings.

45. The apparatus of any preceding apparatus claim, wherein the means comprises: at least one processor; and at least one memory storing instructions that, when executed by at least one processor, cause the performance of the apparatus.

46. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between the user plane function and a user equipment, determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification;sending, by the non-3GPP intermediate network entity to the user plane function, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user plane function comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets have encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user equipment supports decapsulation for explicit congestion notification; and performing one of the following: based on the user equipment supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user equipment over a second tunnel between the non- 3 GPP intermediate network entity and the user equipment, the one or more packets with the explicit congestion notification markings; or based on the user equipment not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

47. The apparatus according to claim 46, wherein: determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises: determining by the non-3GPP intermediate network entity to send the indication implicitly based on receiving L4S (Low Latency Low Loss Scalable throughput) indication from the user plane function; and the sending the indication comprises sending, in response to receiving the L4S indication and by the non-3GPP intermediate network entity, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification.

48. The apparatus according to claim 46, wherein: determining by the non-3GPP intermediate network entity to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises: receiving, by the non-3GPP intermediate network entity, explicit indication by a 5G network function to send indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; and the sending the indication comprises sending, in response to receiving the explicit indication, sending the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification.

49. The apparatus according to claim 47 or 48, wherein the sending, in response to receiving the L4S (Low Latency Low Loss Scalable throughput) indication and by the non-3GPP intermediate network entity, the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification is performed either via session management function to the user plane function or directly to the user plane function using GTP-U header information.

50. The apparatus according to any of claims 46 to 49, wherein: the determining whether the user equipment supports decapsulation for explicit congestion notification determines the user equipment supports decapsulation based on receiving by the non-3GPP intermediate network entity an indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification; and the sending the one or more packets with the explicit congestion notification markings is performed in response to the indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification.

51. The apparatus according to claim 50, wherein the sending the one or more packets with the explicit congestion notification markings using Layer 2 quality of service mechanisms toclassify L4S (Low Latency Low Loss Scalable throughput) traffic having the explicit congestion notification markings.

52. The apparatus according to claim 50 or 51, wherein: the sending the indication to the user plane function that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises sending an indication along with indication of supported L2 quality of service fields via user-plane signaling; and the one or more memories further store instructions that, when executed by the one or more processors, cause the apparatus at least to perform receiving, by the non-3GPP intermediate network entity, explicit congestion notification field information having L2 quality of service fields in the flow that match the supported L2 quality of service fields.

53. The apparatus according to any of claims 46 to 49, wherein: the determining whether the user equipment supports decapsulation for explicit congestion notification determines the user equipment does not support decapsulation in response to the non-3GPP intermediate network entity not receiving an indication from the user equipment that the user equipment supports decapsulation for explicit congestion notification; and addressing, by the non-3GPP intermediate network entity, the congestion via one or more mechanisms.

54. The apparatus according to claim 53, wherein the one or more mechanisms comprise dropping one or more packets to address the congestion.

55. The apparatus according to claim 53, wherein the one or more mechanisms comprise sending, by the non-3GPP intermediate network entity to the user equipment over the second tunnel, the one or more packets without the explicit congestion notification markings.

56. The apparatus according to any of claims 46 to 55, wherein the non-3GPP intermediate network entity comprises one of the following: a N3IWF; a TNGF; or a W-AGF.

57. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, determining, by the user plane function, whether the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function using explicit congestion notification markings in one or more packets received for forwarding to the non-3GPP intermediate network entity, that congestion was experienced; performing one of the following: based on a determination the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification, sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings; or based on a determination the non-3GPP intermediate network entity does not support decapsulation for explicit congestion notification, addressing by the user plane function the congestion via one or more mechanisms.

58. The apparatus according to claim 57, wherein the one or more memories further store instructions that, when executed by the one or more processors, cause the apparatus at least to perform, based on the determination the user plane function does not support decapsulation for explicit congestion notification, addressing, by the user plane function, the congestion via one or more mechanisms.

59. The apparatus according to claim 58, wherein the one or more mechanisms comprises dropping the one or more packets to address the congestion.

60. The apparatus according to claim 58, wherein the one or more mechanisms comprises sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets without the explicit congestion notification markings.

61. The apparatus according to claim 57, wherein: the one or more memories further store instructions that, when executed by the one or more processors, cause the apparatus at least to perform receiving, by the user plane function, indication from the non-3GPP intermediate network entity that the non- 3 GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user plane function, the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification based on the receiving the indication from the non-3GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; and sending, by the user plane function toward the non-3GPP intermediate network entity, the one or more packets with the explicit congestion notification markings.

62. The apparatus according to claim 61, wherein the receiving the indication from the non- 3 GPP intermediate network entity that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification comprises receiving the indication that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification for the non-3GPP intermediate network entity from the non-3GPP intermediate network entity or from an session management function.

63. The apparatus according to any of claims 57 to 62, wherein the non-3GPP intermediate network entity comprises one of the following: a N3IWF; a TNGF; or a W-AGF.

64. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending indication, by the user equipment to the non- 3 GPP intermediate network entity, that the user equipment supports decapsulation for explicit congestion notification;receiving, by the user equipment, one or more packets over a tunnel from the user equipment to the non-3GPP intermediate network entity, the one or more packets comprising at least explicit congestion notification markings; decapsulating, by the user equipment, the one or more packets; determining, by the user equipment using the decapsulated one or more packets, that congestion has occurred in the tunnel; and sending, by the user equipment toward an application to which the one or more packets are directed, indication that congestion has occurred.

65. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a non-third generation partnership project (non-3GPP) intermediate network entity connected to a user plane function in a cellular network and located for a flow in a network between a user equipment and a user plane function, determining by the non-3GPP intermediate network entity to send indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; sending, by the non-3GPP intermediate network entity to the user equipment, the indication to the user equipment that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the non-3GPP intermediate network entity, that one or more packets received over a first tunnel between the non-3GPP intermediate network entity from the user equipment comprise at least encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity using the encapsulated explicit congestion notification markings, that congestion was experienced in the network because at least one of the one or more packets has encapsulated explicit congestion notification markings; determining, by the non-3GPP intermediate network entity, whether the user plane function supports decapsulation for explicit congestion notification; and performing one of the following:based on the user plane function supporting decapsulation and determining that congestion was experienced, sending, by the non-3GPP intermediate network entity to the user plane function over a second tunnel between the non-3GPP intermediate network entity and the user plane function, the one or more packets with the explicit congestion notification markings; or based on the user plane function not supporting decapsulation and determining that congestion was experienced, addressing the congestion using one or more mechanisms.

66. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a user plane function in a cellular network and connected to a non-third generation partnership project (non-3GPP) intermediate network entity, sending, by the user plane function to the non-3GPP intermediate network entity, indication that the user plane function supports decapsulation for explicit congestion notification; receiving, by the user plane function from the non-3GPP intermediate network entity, one or more packets having explicit congestion notification markings; performing, by the user plane function, decapsulation of the one or more packets to determine that the explicit congestion notification markings are in the one or more packets; and sending, by the user plane function toward a destination, the one or more packets with markings indicating congestion has occurred.

67. An apparatus, comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the apparatus at least to perform: for a user equipment connected to a non-third generation partnership project (non-3GPP) intermediate network entity, receiving indication, by the user equipment from the non-3GPP intermediate network entity, that the non-3GPP intermediate network entity supports decapsulation for explicit congestion notification; determining, by the user equipment, congestion has occurred for one or more packets; andsending, by the user equipment toward the non-3GPP intermediate network entity, the one or more packets that are marked with explicit congestion notification markings.

68. A computer program, comprising instructions for performing the methods of any of claims 1 to 22, when the computer program is run on an apparatus.

69. The computer program according to claim 68, wherein the computer program is a computer program product comprising a computer-readable medium bearing instructions embodied therein for use with the apparatus.

70. The computer program according to claim 68, wherein the computer program is directly loadable into an internal memory of the apparatus.

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