Data plane forwarding enhancement methods for ubiquitous network producer mobility

Abstract

The present application relates to the technical field of data plane forwarding of named data network, in particular to a data plane forwarding enhancement method for ubiquitous network producer mobility. The method is used to solve the problems that interest packets are still transferred to the old path when the producer switches the access node in the ubiquitous network, the PIT back path is inconsistent, and the interest packets are discarded during the route convergence. A mobile binding table is established in the data plane. The old access node enters the proxy forwarding mode based on the local control interest packet. The recovery interest packet is generated for the unsatisfied interest entry. The recovery interest packet and the newly arrived interest packet are forwarded to the new access node according to the two-dimensional coordinate identification of the new access node. The new access node forwards the interest packet through the producer access link and returns the data packet based on the PIT record. Meanwhile, the previous hop node is triggered to re-express the backtracking interest packet through NACK, which is suitable for producer mobility scenarios such as low-orbit satellite networks.

Description

Technical Field

[0001] This invention relates to the field of data plane forwarding technology in named data networks, specifically to a data plane forwarding enhancement method for ubiquitous network producer mobility. Background Technology

[0002] Ubiquitous networks, such as low-Earth orbit satellite networks and integrated space-air-ground networks, are characterized by wide node distribution, rapid link changes, and frequent changes in access relationships. Named data networks use content names as the basis for forwarding, forward interest packets through the FIB, and utilize PIT to record the reverse path, enabling data packets to return along the requested path. In producer mobility scenarios, existing methods typically rely on route updates, mobility anchors, control plane notifications, or consumer retransmissions to restore communication, ensuring that interest packets sent by consumers reach the moved producer again.

[0003] However, when a producer switches from an old access node to a new access node, the forwarding plane may still contain forwarding states pointing to the old access node, causing interest packets to continue to arrive at the old path and resulting in invalid forwarding. Even if the interest packet can reach the new access node, the original PIT record and the new backhaul path may be inconsistent, causing data packet backhaul to be blocked. At the same time, during route convergence, interest packets are also prone to backtracking and misjudgment and dropping due to changes in the optimal outgoing interface, affecting the communication continuity during the producer's movement. Therefore, a data plane forwarding enhancement method for ubiquitous network producer mobility is needed to solve the above problems. Summary of the Invention

[0004] To address the above problems, this invention provides the following technical solution: a data plane forwarding enhancement method for ubiquitous network producer mobility, applied to the forwarding plane of a ubiquitous network based on named data networks, wherein the ubiquitous network includes a low-Earth orbit satellite network, and the forwarding nodes in the ubiquitous network forwarding plane maintain FIB and PIT, the method comprising: S1. Establish a mobility binding table in the data plane of the forwarding node. The mobility binding table is used to record the producer namespace prefix, the producer mobility working mode, the two-dimensional coordinate identifier of the new access node, and the valid information of the agent status. S2. Before the producer switches from the old access node to the new access node, the old access node receives and verifies the local control interest packet sent by the producer. After verification, the old access node updates the mobile binding table according to the producer namespace prefix, the two-dimensional coordinate identifier of the new access node, the switching effect information and the agent status validity information carried in the local control interest packet. S3. After the handover effective time determined according to the handover effective information is reached, the old access node switches the producer mobile working mode corresponding to the producer namespace prefix to the proxy forwarding mode, generates a recovery interest packet for the unsatisfied interest entries in the local PIT that match the producer namespace prefix, and forwards the recovery interest packet and the newly arrived interest packet that matches the producer namespace prefix to the new access node according to the two-dimensional coordinate identifier of the new access node. S4. The new access node forwards the received recovery interest packet or the newly arrived interest packet to the producer via the producer access link, and sends back the data packet returned by the producer based on the PIT record formed during the forwarding process. S5. During route convergence, intermediate forwarding nodes determine whether the optimal outgoing interface of the arriving interest packet coincides with the incoming interface based on the updated FIB. If they coincide, a NACK packet is returned to the previous hop forwarding node corresponding to the incoming interface, so that the previous hop forwarding node re-expresses the arriving interest packet based on the updated FIB.

[0005] Furthermore, the producer mobility working mode in the mobility binding table includes at least a normal forwarding mode and a proxy forwarding mode. The proxy status validity information includes the proxy status expiration time. The mobility binding table also records a recovery flag. The proxy status expiration time is used to limit the duration for which the old access node maintains the proxy forwarding mode. The recovery flag is used to identify whether the PIT unsatisfied interest entries corresponding to the producer namespace prefix have undergone restorative re-expression.

[0006] Furthermore, the local control interest packet carries a local scope prefix, a handover notification operation identifier, a producer namespace prefix, a new access node two-dimensional coordinate identifier, handover effective information, proxy status validity information, a timestamp field, an incrementing sequence number field, signature metadata, and a signature value. The local scope prefix is ​​used to restrict the forwarding of the local control interest packet within one hop. The timestamp field and the incrementing sequence number field are used together for deduplication and replay detection.

[0007] Furthermore, the old access node pre-stores a control public key identifier bound to the producer namespace prefix to verify the legitimacy of the local control interest packet, including: Verify the signature value based on the control public key identifier; A freshness check is performed based on the timestamp field and the incrementing sequence number field in the local control interest packet; When the signature verification and freshness check pass, the producer namespace prefix, the two-dimensional coordinate identifier of the new access node, the switching effect information, and the agent status validity information are written into the mobile binding table; otherwise, the local control interest packet is discarded.

[0008] Furthermore, the step of generating restorative interest packets for unsatisfied interest entries in the local PIT that match the producer namespace prefix, and forwarding the restorative interest packets to the new access node according to the two-dimensional coordinate identifier of the new access node, includes: Traverse the local PIT using the producer namespace prefix as the matching condition; PIT entries that have not received corresponding data packets and have not timed out are selected as the unsatisfied interest entries. A restorative interest package is generated based on the unmet interest items, and the restorative interest package is set with a nonce different from that of the original interest package corresponding to the unmet interest items; The restorative interest packet is forwarded to the new access node based on the two-dimensional coordinate identifier of the new access node; After completing the restorative interest packet re-expression corresponding to the producer namespace prefix, the restoration flag position corresponding to the producer namespace prefix in the mobile binding table is set to the restored state.

[0009] Furthermore, forwarding new arrival interest packets matching the producer namespace prefix to the new access node according to the two-dimensional coordinate identifier of the new access node includes: Query the mobile binding table at the old access node; When the name prefix of the newly arrived interest packet matches the producer namespace prefix, and the corresponding mobile binding entry is determined to be in the valid period of proxy forwarding mode according to the proxy status validity information, the forwarding of the newly arrived interest packet according to the old access node local delivery path is stopped. The PIT entry corresponding to the newly arrived interest packet is maintained according to the named data network forwarding process, and the next-hop forwarding interface is selected based on the two-dimensional coordinate identifier of the new access node.

[0010] Furthermore, the recovering interest packet or the newly arrived interest packet is an interest packet to be forwarded, and the two-dimensional coordinate identifier includes the orbital plane number and the satellite's number within the orbital plane. Forwarding the interest packet to be forwarded to the new access node according to the two-dimensional coordinate identifier of the new access node includes: Obtain the two-dimensional coordinate identifier of the current forwarding node, and compare the deviations between the two-dimensional coordinate identifier of the current forwarding node and the two-dimensional coordinate identifier of the newly accessed node in terms of orbital plane number and satellite in orbital plane number; When the orbital plane number in the two-dimensional coordinate identifier of the current forwarding node is not equal to the orbital plane number in the two-dimensional coordinate identifier of the new access node, the adjacent node that can make the orbital plane number move closer to the new access node is selected as the next hop. When the orbital plane number in the two-dimensional coordinate identifier of the current forwarding node is equal to the orbital plane number in the two-dimensional coordinate identifier of the new access node, and the satellite's orbital plane number in the two-dimensional coordinate identifier of the current forwarding node is not equal to the satellite's orbital plane number in the two-dimensional coordinate identifier of the new access node, the adjacent node that can make the satellite's orbital plane number move closer to the new access node is selected as the next hop. When the two-dimensional coordinate identifier of the current forwarding node is the same as that of the new access node, the interest packet to be forwarded is handed over to the new access node for producer access link forwarding processing.

[0011] Furthermore, the new access node forwards the received recovery interest packet or the newly arrived interest packet to the producer via the producer access link, and sends back the data packet returned by the producer based on the PIT record formed during the forwarding process, including: The new access node determines the corresponding producer access link based on the producer namespace prefix; The producer access link forwards the restorative interest packet or the newly arrived interest packet to the producer. The data packets returned by the producer are received, and the data packets are transmitted back hop by hop according to the PIT records formed during the forwarding process of the recovering interest packets or the newly arrived interest packets.

[0012] Furthermore, during route convergence, the intermediate forwarding node determines whether the optimal outgoing interface of the arriving interest packet coincides with the incoming interface based on the updated FIB. If they coincide, it returns a NACK packet to the previous hop forwarding node corresponding to the incoming interface, causing the previous hop forwarding node to rewrite the arriving interest packet based on the updated FIB, including: The intermediate forwarding node queries the updated FIB based on the name prefix of the arriving interest packet to determine the optimal outgoing interface of the arriving interest packet; When the optimal outgoing interface coincides with the incoming interface of the arriving interest packet, delete or invalidate the local PIT entry corresponding to the arriving interest packet. The intermediate forwarding node returns a NACK packet corresponding to the arriving interest packet to the previous hop forwarding node corresponding to the ingress interface; After receiving the NACK packet, the previous hop forwarding node reselects the outgoing interface based on the updated FIB and re-expresses the arriving interest packet.

[0013] Furthermore, after the proxy state expires, the old access node cleans up the mobile binding entries corresponding to the producer namespace prefix, including: Delete or invalidate the two-dimensional coordinate identifier of the new access node, the agent status expiration time, and the recovery flag corresponding to the producer namespace prefix; Restore the producer's mobile working mode from the proxy forwarding mode to the normal forwarding mode; This enables subsequent interest packets matching the producer's namespace prefix to be forwarded via the normal named data network according to the updated FIB.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This data plane forwarding enhancement method for ubiquitous network producer mobility establishes a mobility binding table in the data plane, recording the producer's namespace prefix, the new access node's two-dimensional coordinate identifier, and the agent's valid state information. This enables the old access node to promptly enter agent forwarding mode after producer handover, forwarding interest packets that would otherwise still reach the old path to the new access node, reducing interest packet idleness and loss caused by forwarding state lag. Furthermore, by generating restorative interest packets for unmet interest entries in the local PIT and re-expressing them to the new access node, requests that were suspended before the handover can re-establish forwarding states for the new access path, thus mitigating the problem of packet backhaul obstruction caused by inconsistencies between the original PIT records and the new backhaul path. Finally, by determining whether the optimal outgoing and incoming interfaces of interest packets overlap during route convergence and returning a NACK packet when they overlap to trigger the previous hop node to re-express the interest packet based on the updated FIB, this avoids interest packets being misjudged as loops and directly discarded during normal path adjustment, thereby improving forwarding continuity and data backhaul reliability during producer mobility. Attached Figure Description

[0015] Figure 1 A schematic diagram of the overall process of the data plane forwarding enhancement method for ubiquitous network producer mobility provided by the present invention; Figure 2 A schematic diagram illustrating the retransmission of interest packets and data packet return in a consumer mobile switching scenario; Figure 3 A schematic diagram illustrating the loss of interest packets and failure of data packet return paths in a producer mobility switching scenario; Figure 4 This is a schematic diagram of the forwarding path of interest packets in transit under the condition that the next hop remains unchanged before the FIB update. Figure 5 This diagram illustrates the forwarding path of in-transit interest packets in the case of next-hop redirection and next-hop backtracking after FIB update. Figure 6 A schematic diagram illustrating same-orbit and cross-orbit switching scenarios for producers in a low-Earth orbit satellite network; Figure 7 A schematic diagram illustrating a scenario where producers switch over long distances across a reverse gap in a low-Earth orbit satellite network. Figure 8 The graph shows the average interest packet retrieval latency per second under the native NDN mechanism in a satellite orbit switching scenario. Figure 9 A graph showing the latency variation of single interest packet retrieval under the native NDN mechanism in a satellite orbit switching scenario; Figure 10 The graph shows the average interest packet retrieval latency per second under the native NDN mechanism in a satellite cross-orbit access handover scenario. Figure 11 A graph showing the latency variation of single interest packet retrieval in a satellite cross-orbit access handover scenario using the native NDN mechanism; Figure 12 The graph shows the average interest packet retrieval latency per second for the native NDN mechanism in a long-distance satellite switching scenario across a reverse gap. Figure 13 A graph showing the latency variation of single interest packet retrieval in a long-distance satellite switching scenario across a reverse gap using the native NDN mechanism; Figure 14 The graph shows the average interest packet retrieval latency per second under the NACK-triggered mechanism in a long-distance switching scenario across a satellite reverse gap. Figure 15 A graph showing the latency variation of single interest packet retrieval under the NACK-triggered mechanism in a long-distance switching scenario across a satellite reverse gap; Figure 16 This is a graph showing the average interest packet retrieval latency per second in a long-distance switching scenario across a satellite reversal gap, according to the present invention. Figure 17 This is a graph showing the latency variation of single interest packet retrieval in a long-distance switching scenario across a satellite cross-reverse gap, according to the present invention. Figure 18 A comparison chart showing the changes in PIT occupancy rates under different forwarding mechanisms in a long-distance switching scenario where satellites cross reverse gaps. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Please see Figure 1 This implementation is applied to the forwarding plane of a ubiquitous network based on named data networks, which may include low-Earth orbit (LEO) satellite networks. Satellite nodes in the LEO satellite network operate the NDN forwarding plane as forwarding nodes. Each forwarding node maintains a File Interface Board (FIB) and a Point of Interest (PIT). The FIB is used to select the next-hop forwarding interface based on the name prefix, and the PIT is used to record the ingress interface, egress interface, and unmet status of interest packets so that the data packets can return hop by hop along the reverse path established by the interest packets. Figure 2 This demonstrates a scenario where communication can be restored using the NDN request-response mechanism even after retransmission of interest packets in a mobile consumer environment. Figure 3 This illustrates the problem that after a producer moves, the original packets of interest continue to point to the old access node, and the packets cannot be transmitted back normally along the new path. This shows that this implementation mainly addresses the data plane enhancement for old path failure, PIT state inconsistency, and packet of interest backtracking during route convergence caused by producer movement.

[0019] This invention provides a data plane forwarding enhancement method for ubiquitous network producer mobility, applied to the forwarding plane of a ubiquitous network based on named data networks, wherein the ubiquitous network includes a low-Earth orbit satellite network, and the forwarding nodes in the ubiquitous network forwarding plane maintain FIB and PIT. The method includes: S1. Establish a mobility binding table in the data plane of the forwarding node. The mobility binding table is used to record the producer namespace prefix, the producer mobility working mode, the two-dimensional coordinate identifier of the new access node, and the valid information of the agent status. Specifically, a mobility binding table is added to the data plane of each low-Earth orbit satellite forwarding node. This table can be deployed alongside the FIB and PIT in the forwarding status maintenance module of the forwarding node. The producer namespace prefix identifies the range of names of content or services provided by the moved producer. For example, prefixes like / texts / intro and / producer / service indicate the range of interest packets the producer can respond to. The producer mobility working mode indicates whether the forwarding node currently processes the producer namespace prefix according to normal NDN forwarding logic, or whether it needs to act as an old access node to perform proxy forwarding. The new access node's two-dimensional coordinate identifier indicates the location of the access satellite after the producer's movement, allowing the old access node to forward interest packets to the new access node without waiting for full network routing convergence. Proxy status validity information limits the valid range of proxy forwarding, preventing old access nodes from retaining expired mobility status for extended periods, thus affecting subsequent normal forwarding.

[0020] Furthermore, in one embodiment provided in this application, the producer mobile working mode in the mobile binding table includes at least a normal forwarding mode and a proxy forwarding mode. The proxy status validity information includes a proxy status expiration time. The mobile binding table also records a recovery flag bit. The proxy status expiration time is used to limit the duration for which the old access node maintains the proxy forwarding mode. The recovery flag bit is used to identify whether the PIT unsatisfied interest entries corresponding to the producer namespace prefix have undergone restorative re-expression.

[0021] Specifically, normal forwarding mode means that the forwarding node does not assume the producer's mobile proxy function, and interest packets matching the producer's namespace prefix are still forwarded normally via FIB using NDN. Proxy forwarding mode means that the old access node temporarily assumes the proxy anchor function after the producer leaves, performing targeted forwarding of interest packets matching the producer's namespace prefix. The proxy state expiration time can be notified to the old access node by the producer before the switchover, or it can be generated by the old access node based on its local routing convergence cycle. Before this time expires, the old access node retains the mobile binding entries and handles restorative forwarding; after this time expires, the old access node releases the relevant mobile state. The recovery flag is used to record whether the old access node has performed restorative re-expression for unmet interest entries in its local PIT. If the recovery flag indicates that recovery has been achieved, the old access node can avoid repeatedly generating restorative interest packets for the same producer's namespace prefix, thereby reducing duplicate requests and PIT state bloat.

[0022] S2. Before a producer switches from an old access node to a new access node, the old access node receives and verifies the local control interest packet sent by the producer. After successful verification, the old access node updates the mobile binding table based on the producer namespace prefix, the new access node's two-dimensional coordinate identifier, the switchover activation information, and the agent status validity information carried in the local control interest packet.

[0023] Specifically, before a producer switches from an old access node to a new access node, the producer sends a Local Control Interest Packet (RCIP) to the old access node through the still-connected access link. This RIP is not distributed across the network as a regular content request; instead, it is received and processed by the old access node within its local scope. Upon receiving the RIP, the old access node first identifies the handover notification operation identifier and extracts the producer's namespace prefix, the new access node's two-dimensional coordinates, the handover activation information, and the proxy status validity information. The handover activation information indicates when the old access node switches from normal forwarding mode to proxy forwarding mode; the new access node's two-dimensional coordinates indicate the target location for subsequent proxy forwarding; and the proxy status validity information determines the boundaries for the old access node to maintain its proxy forwarding state.

[0024] Furthermore, in one embodiment provided in this application, the local control interest packet carries a local scope prefix, a handover notification operation identifier, a producer namespace prefix, a new access node two-dimensional coordinate identifier, handover effective information, proxy status validity information, a timestamp field, an incrementing sequence number field, signature metadata, and a signature value. The local scope prefix is ​​used to restrict the forwarding of the local control interest packet within one hop. The timestamp field and the incrementing sequence number field are used together for deduplication and replay detection.

[0025] Specifically, the local scope prefix can use a name component to limit the local forwarding scope, ensuring that the control interest packet is only valid within the one-hop link between the producer and the old access node, preventing handover control information from being propagated to other satellite nodes by ordinary forwarding strategies. The handover notification operation identifier is used by the old access node to distinguish whether the interest packet is a mobility control request or a content request. The timestamp field reflects the generation time of the control interest packet, and the incrementing sequence number field reflects the order in which the producer continuously sends control interest packets. The old access node can combine the processed timestamp and incrementing sequence number into its local cache, and discard subsequent identical or outdated control interest packets to avoid replay attacks or repeated updates to the mobility binding table. The signature metadata describes the signature algorithm, key identifier, or auxiliary information required for signature verification, and the signature value ensures that the local control interest packet was indeed generated by the corresponding producer or authorized entity.

[0026] Furthermore, in one embodiment provided in this application, the old access node pre-stores a control public key identifier bound to the producer namespace prefix, and performs legality verification on the local control interest packet, including: verifying the signature value according to the control public key identifier; performing a freshness check according to the timestamp field and the incrementing sequence number field in the local control interest packet; when the signature verification passes and the freshness check passes, writing the producer namespace prefix, the new access node's two-dimensional coordinate identifier, the handover effective information, and the agent status validity information into the mobile binding table; otherwise, discarding the local control interest packet.

[0027] Specifically, during the producer's access period, the old access node establishes a binding relationship between the producer's namespace prefix and the control public key identifier. Upon receiving a local control interest packet, the old access node first looks up the corresponding control public key identifier based on the producer's namespace prefix and uses this identifier to verify whether the signature value matches the content of the control interest packet. If the signature verification fails, it indicates that the control interest packet may have been forged, tampered with, or originated from an unauthorized entity, and the old access node does not update the mobility binding table. If the signature verification passes, the old access node continues to perform a freshness check based on the timestamp and incrementing sequence number fields to determine whether the control interest packet is within the allowed time window and whether the incrementing sequence number is greater than the processed sequence number. Only when both signature verification and freshness check pass will the old access node write the producer's namespace prefix, the new access node's two-dimensional coordinate identifier, the handover activation information, and the proxy status validity information into the mobility binding table, thus forming the status basis for subsequent proxy forwarding and restorative re-expression.

[0028] S3. After the handover effective time determined according to the handover effective information is reached, the old access node switches the producer mobility working mode corresponding to the producer namespace prefix to the proxy forwarding mode, generates a recovery interest packet for the unsatisfied interest entries in the local PIT that match the producer namespace prefix, and forwards the recovery interest packet and the newly arrived interest packet matching the producer namespace prefix to the new access node according to the two-dimensional coordinate identifier of the new access node.

[0029] Specifically, the old access node initiates local handover timing or status monitoring based on the handover activation information. After the handover activation time arrives, the original access link between the producer and the old access node may have been disconnected or is about to be disconnected, such as... Figure 3 As shown, if interest packets are still forwarded along the old path, they will reach the old access node, which can no longer deliver to the producer, resulting in packet loss or timeout. Therefore, after the handover takes effect, the old access node switches the working mode corresponding to the producer namespace prefix from normal forwarding mode to proxy forwarding mode. At this time, the old access node processes both interest entries that were pending in the local PIT before the handover but not yet satisfied, and newly arriving interest packets that match the producer namespace prefix after the handover.

[0030] For interest entries that were suspended before the handover, the old access node treats them as requests whose reverse path may be compromised. Instead of waiting for timeout retransmissions from the consumer side, the old access node proactively generates a recovery interest packet in the data plane and forwards it to the new access node based on the new access node's two-dimensional coordinates in the mobility binding table. During the forwarding of the recovery interest packet, PIT records are re-established at nodes along the route, enabling data packets returned by the producer to be transmitted back along the new PIT reverse path. For new interest packets arriving at the old access node after the handover, the old access node no longer attempts to deliver them through the now-defunct local producer access link. Instead, it forwards them to the new access node according to the new access node's two-dimensional coordinates, allowing the old access node to act as a proxy anchor during the routing convergence window.

[0031] Furthermore, in one embodiment provided by this application, the step of generating a recovery interest packet for unsatisfied interest entries in the local PIT that match the producer namespace prefix, and forwarding the recovery interest packet to the new access node according to the two-dimensional coordinate identifier of the new access node, includes: traversing the local PIT using the producer namespace prefix as the matching condition; filtering PIT entries that have not received corresponding data packets and have not timed out as the unsatisfied interest entries; generating a recovery interest packet based on the unsatisfied interest entries, and setting the recovery interest packet with a Nonce different from that of the original interest packet corresponding to the unsatisfied interest entry; forwarding the recovery interest packet to the new access node according to the two-dimensional coordinate identifier of the new access node; and after completing the re-expression of the recovery interest packet corresponding to the producer namespace prefix, setting the recovery flag position in the mobile binding table corresponding to the producer namespace prefix to the recovered state.

[0032] Specifically, the old access node traverses its local PIT using the producer namespace prefix as a filter, selecting only entries for which no corresponding data packets have been received and which have not exceeded their PIT validity period. PIT entries for which data packets have already been received do not need to be restored, and expired PIT entries can be deleted by the normal PIT cleanup mechanism. For the filtered unsatisfied interest entries, the old access node copies their name prefix and necessary selector information to generate a recovery interest packet, while setting a new Nonce. This ensures that the recovery interest packet and the original interest packet are identified as new requests during NDN loop detection, preventing nodes along the path from mistakenly identifying duplicate interest packets due to identical Nonces. After the recovery interest packet is sent, forwarding nodes along the path maintain new PIT entries based on their ingress and egress interfaces. Data packets returned by the producer can be hop-by-hop back to the old access node along the new PIT record formed by the recovery interest packet, and then the old access node back to the consumer side based on the original PIT record. After the recovery interest packet is re-expressed, the old access node sets the recovery flag to the restored state to avoid repeated scanning and re-expression of the same producer namespace prefix during the proxy state validity period.

[0033] Furthermore, in one embodiment provided in this application, forwarding the newly arriving interest packet matching the producer namespace prefix to the new access node according to the two-dimensional coordinate identifier of the new access node includes: querying the mobility binding table at the old access node; when the name prefix of the newly arriving interest packet matches the producer namespace prefix, and the corresponding mobility binding table entry is determined to be in the valid period of proxy forwarding mode according to the proxy status validity information, stopping the forwarding of the newly arriving interest packet according to the local delivery path of the old access node; maintaining the PIT entry corresponding to the newly arriving interest packet according to the named data network forwarding process, and selecting the next-hop forwarding interface according to the two-dimensional coordinate identifier of the new access node.

[0034] Specifically, upon receiving a newly arrived interest packet, the old access node first checks whether the packet name matches the producer namespace prefix in the mobility binding table using the longest prefix matching method. If it doesn't match, the interest packet is unrelated to the current producer mobility event and is still forwarded normally according to the FIB. If it matches, it continues to determine whether the proxy forwarding mode is still valid based on the proxy status validity information. When the proxy forwarding mode is valid, the old access node stops delivering interest packets to the old local producer access link to prevent the interest packet from being sent to an unreachable producer access direction; at the same time, the old access node still maintains the PIT entry corresponding to the newly arrived interest packet according to the NDN mechanism so that subsequent data packets can be returned along the original request direction. The next-hop forwarding interface is jointly determined by the two-dimensional coordinate identifier of the new access node and the two-dimensional coordinate identifier of the current forwarding node, enabling the interest packet to move towards the new access node without relying on the not yet fully converged network-wide FIB.

[0035] Furthermore, in one embodiment provided in this application, the recoverable interest packet or the newly arrived interest packet is an interest packet to be forwarded, and the two-dimensional coordinate identifier includes an orbital plane number and a satellite's position within the orbital plane. Forwarding the interest packet to be forwarded to the new access node according to the new access node's two-dimensional coordinate identifier includes: obtaining the current forwarding node's two-dimensional coordinate identifier and comparing the deviations between the current forwarding node's two-dimensional coordinate identifier and the new access node's two-dimensional coordinate identifier in terms of the orbital plane number and the satellite's position within the orbital plane; when the orbital plane number in the current forwarding node's two-dimensional coordinate identifier is not equal to the orbital plane number in the new access node's two-dimensional coordinate identifier, selecting a method that enables... The neighboring node whose orbital plane number is closer to the new access node is selected as the next hop; when the orbital plane number in the two-dimensional coordinate identifier of the current forwarding node is equal to the orbital plane number in the two-dimensional coordinate identifier of the new access node, and the satellite's orbital plane number in the two-dimensional coordinate identifier of the current forwarding node is not equal to the satellite's orbital plane number in the two-dimensional coordinate identifier of the new access node, the neighboring node that can make the satellite's orbital plane number closer to the new access node is selected as the next hop; when the two-dimensional coordinate identifier of the current forwarding node is the same as the two-dimensional coordinate identifier of the new access node, the interest packet to be forwarded is handed over to the new access node for producer access link forwarding processing.

[0036] Specifically, such as Figure 6 and Figure 7 As shown, low-Earth orbit (LEO) satellite networks can describe satellite node locations using orbital planes and satellite indices within those planes. The orbital plane number in the two-dimensional coordinate identifier distinguishes the orbital plane to which a satellite belongs, while the satellite's indices within the orbital plane distinguish adjacent satellites within the same orbital plane. When an older access node or intermediate forwarding node forwards a packet of interest, it first reads its own two-dimensional coordinate identifier and the new access node's two-dimensional coordinate identifier, comparing their deviations in two dimensions. If the orbital plane numbers are different, it indicates that the packet of interest still needs to move across orbital planes, and the forwarding node prioritizes selecting an adjacent satellite whose orbital plane number is close to the new access node's orbital plane number as the next hop. If the orbital plane numbers are the same but the indices within the orbital plane are different, it indicates that the packet of interest has already entered the target orbital plane, and the forwarding node selects an adjacent satellite whose indices within the orbital plane are close to the new access node's indices as the next hop. If the current forwarding node's two-dimensional coordinate identifier is the same as the new access node's two-dimensional coordinate identifier, it indicates that the packet of interest has reached the new access node. In this case, inter-satellite forwarding is no longer performed; instead, the new access node performs local forwarding processing for the producer access link. By forwarding the aforementioned two-dimensional coordinates, the old access node can guide the recovery interest packets and newly arriving interest packets to the access direction after the producer has moved, even before the FIB has been fully updated.

[0037] Furthermore, in one embodiment provided in this application, after the proxy state expiration time arrives, the old access node cleans up the mobile binding table entry corresponding to the producer namespace prefix, including: deleting or invalidating the two-dimensional coordinate identifier of the new access node, the proxy state expiration time, and the recovery flag bit corresponding to the producer namespace prefix; restoring the producer's mobile working mode from proxy forwarding mode to normal forwarding mode; and enabling subsequent interest packets matching the producer namespace prefix to be forwarded normally via the named data network according to the updated FIB.

[0038] Specifically, the expiration of the proxy state usually indicates that the entire network's FIB has completed or is nearing convergence, and subsequent interest packets can rely on the updated FIB to reach the new access node. After the proxy state expires, the old access node deletes or invalidates the new access node's two-dimensional coordinate identifier, proxy state expiration time, and recovery flag in the mobility binding entry corresponding to the producer namespace prefix, and restores the producer mobility working mode to normal forwarding mode. If it subsequently receives interest packets matching the same producer namespace prefix, the old access node will no longer process them according to the proxy forwarding logic, but will instead perform normal NDN forwarding according to the updated FIB. This cleanup process ensures that the proxy anchor function is only effective during the handover and route convergence window, preventing the old access node from retaining a temporary mobility state for an extended period.

[0039] S4. The new access node forwards the received recovery interest packet or the newly arrived interest packet to the producer via the producer access link, and sends back the data packet returned by the producer based on the PIT record formed during the forwarding process.

[0040] Specifically, upon receiving a recovering interest packet or a newly arrived interest packet, the new access node determines that the corresponding producer has already connected to it via the local producer access link based on the producer namespace prefix in the interest packet name. The new access node forwards the interest packet to the producer and simultaneously records the ingress and egress interface relationships of the interest packet in its local PIT. Upon receiving the interest packet, the producer generates a corresponding data packet, which carries a name matching the interest packet name and returns it to the new access node. Because recovering and newly arrived interest packets have already established PIT records along the way during forwarding to the new access node, the data packet can be relayed hop-by-hop back to the old access node or the consumer side along these PIT records. Figure 3 As shown, without this new PIT path, the data packet may attempt to return along the new path without a suspended state but be dropped by the intermediate node; this implementation forms a new reverse path through restorative interest packets and proxy forwarding, so that the data packets returned by the producer have a matching PIT state.

[0041] Furthermore, in one embodiment provided in this application, the new access node forwards the received recovery interest packet or the newly arrived interest packet to the producer via the producer access link, and sends back the data packet returned by the producer based on the PIT record formed during the forwarding process. This includes: the new access node determining the corresponding producer access link according to the producer namespace prefix; forwarding the recovery interest packet or the newly arrived interest packet to the producer via the producer access link; receiving the data packet returned by the producer, and sending back the data packet hop-by-hop according to the PIT record formed during the forwarding process of the recovery interest packet or the newly arrived interest packet.

[0042] Specifically, a new access node can confirm the producer access link corresponding to the producer's namespace prefix through access management status, producer registration information, or local link status. If a recoverable interest packet arrives at the new access node, the new access node forwards it to the producer as a request to re-establish the reverse path; if a newly arriving interest packet arrives at the new access node, the new access node forwards it to the producer according to the normal NDN interest packet processing procedure. After the data packet returned by the producer arrives at the new access node, the new access node first looks up the PIT entry based on the data packet name. After finding a matching entry, it transmits the data packet back along the ingress interface recorded in the PIT and deletes or updates the satisfied PIT status. Nodes along the way process each hop in the same way until the data packet returns to the consumer side or the original request ingress direction saved by the old access node. This process ensures that after the interest packet is forwarded by the old access node to the new access node, the data packet can be transmitted back along the PIT record established during the actual forwarding.

[0043] S5. During route convergence, intermediate forwarding nodes determine whether the optimal outgoing interface of the arriving interest packet coincides with the incoming interface based on the updated FIB. If they coincide, a NACK packet is returned to the previous hop forwarding node corresponding to the incoming interface, so that the previous hop forwarding node re-expresses the arriving interest packet based on the updated FIB.

[0044] Specifically, such as Figure 4 and Figure 5As shown, during route convergence, FIB updates may cause in-transit interest packets to face three different forwarding states: The first is next-hop unchanged, meaning the optimal outgoing interface specified by the updated FIB remains consistent with the original forwarding direction, and the interest packet can continue to be forwarded along the original path; the second is next-hop redirection, meaning the optimal outgoing interface specified by the updated FIB is different from the old outgoing interface and not equal to the interest packet's incoming interface, and the interest packet can be redirected to a new next hop; the third is next-hop backtracking, meaning the optimal outgoing interface specified by the updated FIB is exactly equal to the interest packet's incoming interface. If the interest packet is directly sent back to the previous hop node corresponding to the incoming interface according to ordinary NDN forwarding logic, the previous hop node may identify the interest packet as a duplicate interest packet or a loop interest packet and discard it. To avoid this misjudgment, when an intermediate forwarding node finds that the optimal outgoing interface coincides with the incoming interface, it does not directly send the interest packet back along the incoming interface, but generates a NACK packet and returns it to the previous hop forwarding node, allowing the previous hop forwarding node to reselect the outgoing interface and re-express the interest packet after its own FIB has been updated.

[0045] Furthermore, in one embodiment provided in this application, during route convergence, the intermediate forwarding node determines whether the optimal outgoing interface of the arriving interest packet coincides with the incoming interface based on the updated FIB. If they coincide, the intermediate forwarding node returns a NACK packet to the previous hop forwarding node corresponding to the incoming interface, so that the previous hop forwarding node re-expresses the arriving interest packet based on the updated FIB. This includes: the intermediate forwarding node queries the updated FIB based on the name prefix of the arriving interest packet to determine the optimal outgoing interface of the arriving interest packet; when the optimal outgoing interface coincides with the incoming interface of the arriving interest packet, the intermediate forwarding node deletes or invalidates the local PIT entry corresponding to the arriving interest packet; the intermediate forwarding node returns a NACK packet corresponding to the arriving interest packet to the previous hop forwarding node corresponding to the incoming interface; after receiving the NACK packet, the previous hop forwarding node reselects an outgoing interface based on the updated FIB and re-expresses the arriving interest packet.

[0046] Specifically, after receiving an arriving interest packet, the intermediate forwarding node queries the updated FIB using the interest packet name prefix and obtains the optimal outgoing interface. If the optimal outgoing interface differs from the incoming interface, the intermediate forwarding node continues to forward the interest packet according to the normal NDN forwarding procedure. If the optimal outgoing interface is the same as the incoming interface, the interest packet is at risk of backtracking. The intermediate forwarding node deletes or invalidates the local PIT entry corresponding to the interest packet to prevent subsequent data packets from returning in an incorrect suspended state and to prevent the same interest packet from forming a long-term unmet state locally. Subsequently, the intermediate forwarding node returns a NACK packet to the previous hop forwarding node corresponding to the incoming interface. After receiving the NACK packet, the previous hop forwarding node no longer simply waits for the consumer to time out and retransmit, but instead reselects an outgoing interface based on its updated FIB and re-expresses the interest packet. If the re-selected outgoing interface still triggers a backtracking judgment in subsequent nodes, the above NACK return and re-expression process can continue until the interest packet is guided to a path that can be forwarded toward the producer or a new access node. In this way, interest packets that might have been misjudged as loops during route convergence can be re-expressed and continue to be transmitted. It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0047] Simulation experiment results description: Combination Figures 8 to 18 The experimental results of this implementation method are explained. Figures 8 to 13 The results show that, under the native NDN mechanism, the latency and packet loss of interest packet retrieval during producer movement are significantly affected by route convergence. Figure 8 and Figure 9 In the scenario of satellite orbit switching, after the producer disconnects from the original access satellite, the native NDN mechanism needs to wait for route convergence. Before route convergence is completed, a large number of interest packets still follow the old route information to reach the failed access point, resulting in the loss of interest packets. After the route is updated, the interest packets in transit mainly exhibit two states: the next hop remains unchanged and the next hop is redirected. Among them, the redirected interest packets incur additional retrieval delays because they detour to the new access point. Figure 10 and Figure 11For satellite cross-orbit access handover scenarios, the overall trend is similar to that of intra-orbit handover. After the route update, the main characteristics remain the same: the next hop remains unchanged, and the next hop is redirected. The cross-orbit redirection path causes the retrieval latency of some interest packets to be higher than the stable latency after the route is fully converged. In the simulation results of one embodiment, the intra-orbit handover scenario recorded an interest packet retrieval latency of approximately 199ms from 439.62s to 439.66s and approximately 159ms from 439.66s to 439.71s; the cross-orbit handover scenario recorded an interest packet retrieval latency of approximately 221ms from 327.91s to 327.965s and approximately 269ms from 327.966s to 328s.

[0048] Figure 12 and Figure 13 This simulation describes the retrieval latency changes in a long-distance handover scenario involving satellites crossing a reverse gap, corresponding to the native NDN mechanism. In this scenario, the producer moves from the original access satellite SAT-C to the new access satellite SAT-D, and the handover involves a reverse gap region where the satellites on both sides move in opposite directions, increasing both the inter-satellite path span and the number of topology hops. Simulation results show that the producer disconnects from the original access satellite SAT-C at 250.9s and the route finally converges at 331s. Between 310.92s and 310.965s, some in-transit interest packets experience next-hop backtracking after FIB updates, and are mistakenly identified as duplicate interest packets or forwarding loops by downstream nodes and discarded, resulting in continuous loss of interest packets during this period. Interest packets between 310.966s and 310.975s require a detour to reach SAT-D due to next-hop redirection, resulting in a retrieval latency of approximately 202ms. Interest packets between 310.976s and 311s have an unchanged next hop, resulting in a retrieval latency of approximately 117ms. The results indicate that in the scenario of long-distance handover in the reverse gap, the native NDN mechanism not only suffers from packet loss during the routing convergence window, but also from misjudgment and dropping caused by the backtracking of interest packets at the moment of FIB update.

[0049] Figure 14 and Figure 15The retrieval latency variation of the NACK-triggered mechanism in a long-distance handover scenario across a satellite cross-reverse gap is shown. Compared to the native NDN mechanism, the NACK-triggered mechanism can provide feedback correction for the interest backtracking problem. When an intermediate node detects a path flip or forwarding failure, it guides the previous hop node to re-express the interest packet through NACK, allowing the interest packets that were originally lost due to backtracking between 310.92s and 310.965s to be re-forwarded, with a retrieval latency of approximately 292ms. This result indicates that the NACK-triggered mechanism can alleviate the instantaneous packet loss caused by backtracking. However, it mainly addresses the backtracking problem at the moment of route update and does not provide proxy protection for failed path forwarding during the longer route convergence process. Therefore, during route convergence, a large number of packet losses similar to those of the native NDN mechanism still occur.

[0050] Figure 16 and Figure 17 This invention addresses the retrieval latency variation in a long-distance handover scenario across a satellite cross-reverse gap. Compared to the native NDN mechanism and the NACK-triggered mechanism, this invention establishes a mobility binding table in the old access node's data plane and puts the old access node into proxy forwarding mode after producer handover, enabling interest packets arriving at the old access node during route convergence to be forwarded to the new access node. Simultaneously, the old access node generates restorative interest packets for unsatisfied interest entries in its local PIT and re-expresses them to the new access node, allowing pending requests before handover to re-establish PIT records for the new access path. Simulation results show that... Figure 16 Of the corresponding changes in average retrieval latency, except for a small number of lost interest packets due to the lack of a new path between SAT-C and SAT-D in time, the interest packet retrieval latency remained relatively stable at approximately 292ms from 251.1s to 310.92s. Figure 17 In the corresponding single-interest packet retrieval latency variation, interest packets sent between 310.92s and 310.965s were all successfully forwarded, with a retrieval latency of approximately 292ms. This result demonstrates that the present invention can simultaneously cover the failed path forwarding problem during route convergence and the interest backtracking problem at the moment of FIB update.

[0051] Figure 18This paper addresses the changes in PIT occupancy rates under different forwarding mechanisms in long-distance handover scenarios involving satellites crossing reverse gaps. In the native NDN mechanism, a large number of interest packets flow to failed paths during route convergence and cannot receive packet return, causing unmet PIT entries to accumulate continuously. This results in a PIT occupancy rate increasing from a steady-state 20% to 60%, leading to significant state pollution and resource congestion. While the NACK-triggered mechanism can correct some packet loss caused by interest backtracking, it still struggles to promptly clear suspended PIT states on failed paths during route convergence due to the lack of proxy forwarding by old access nodes and proactive re-expression mechanisms. This invention, through the combined effects of proxy anchor forwarding, restorative interest packet re-expression, and NACK reverse backtracking processing, stabilizes the PIT occupancy rate at approximately 22% during convergence, reducing resource consumption by approximately 63.3% compared to the native NDN mechanism and approximately 60.7% compared to the NACK-triggered mechanism. The experimental results correspond to the mobile binding table, proxy forwarding, PIT restorative re-expression, and anti-backtracking processing in the aforementioned implementation process, demonstrating that the present invention reduces PIT accumulation on failed paths and improves the continuity of data plane forwarding in producer mobility scenarios.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A data plane forwarding enhancement method for ubiquitous network producer mobility, characterized in that, The method, applied to a ubiquitous network forwarding plane based on named data networks, wherein the ubiquitous network includes a low-Earth orbit satellite network, and the forwarding nodes in the ubiquitous network forwarding plane maintain FIB and PIT, includes: S1. Establish a mobility binding table in the data plane of the forwarding node. The mobility binding table is used to record the producer namespace prefix, the producer mobility working mode, the two-dimensional coordinate identifier of the new access node, and the valid information of the agent status. S2. Before the producer switches from the old access node to the new access node, the old access node receives and verifies the local control interest packet sent by the producer. After verification, the old access node updates the mobile binding table according to the producer namespace prefix, the two-dimensional coordinate identifier of the new access node, the switching effect information and the agent status validity information carried in the local control interest packet. S3. After the handover effective time determined according to the handover effective information is reached, the old access node switches the producer mobile working mode corresponding to the producer namespace prefix to the proxy forwarding mode, generates a recovery interest packet for the unsatisfied interest entries in the local PIT that match the producer namespace prefix, and forwards the recovery interest packet and the newly arrived interest packet that matches the producer namespace prefix to the new access node according to the two-dimensional coordinate identifier of the new access node. S4. The new access node forwards the received recovery interest packet or the newly arrived interest packet to the producer via the producer access link, and sends back the data packet returned by the producer based on the PIT record formed during the forwarding process. S5. During route convergence, intermediate forwarding nodes determine whether the optimal outgoing interface of the arriving interest packet coincides with the incoming interface based on the updated FIB. If they coincide, a NACK packet is returned to the previous hop forwarding node corresponding to the incoming interface, so that the previous hop forwarding node re-expresses the arriving interest packet based on the updated FIB.

2. The data plane forwarding enhancement method for ubiquitous network producer mobility according to claim 1, characterized in that, The producer mobility working modes in the mobility binding table include at least normal forwarding mode and proxy forwarding mode. The proxy status validity information includes the proxy status expiration time. The mobility binding table also records a recovery flag. The proxy status expiration time is used to limit the duration for which the old access node maintains the proxy forwarding mode. The recovery flag is used to identify whether the PIT unsatisfied interest entries corresponding to the producer namespace prefix have undergone restorative re-expression.

3. The data plane forwarding enhancement method for ubiquitous network producer mobility according to claim 1, characterized in that, The local control interest packet carries a local scope prefix, a handover notification operation identifier, a producer namespace prefix, a new access node two-dimensional coordinate identifier, handover effective information, proxy status validity information, a timestamp field, an incrementing sequence number field, signature metadata, and a signature value. The local scope prefix is ​​used to restrict the forwarding of the local control interest packet within one hop. The timestamp field and the incrementing sequence number field are used together for deduplication and replay detection.

4. The data plane forwarding enhancement method for ubiquitous network producer mobility according to claim 3, characterized in that, The old access node pre-stores a control public key identifier bound to the producer namespace prefix, and performs legality verification on the local control interest packet, including: Verify the signature value based on the control public key identifier; A freshness check is performed based on the timestamp field and the incrementing sequence number field in the local control interest packet; When the signature verification and freshness check pass, the producer namespace prefix, the two-dimensional coordinate identifier of the new access node, the switching effect information, and the agent status validity information are written into the mobile binding table; otherwise, the local control interest packet is discarded.

5. The data plane forwarding enhancement method for ubiquitous network producer mobility according to claim 2, characterized in that, The step of generating a recovery interest packet for unsatisfied interest entries in the local PIT that match the producer namespace prefix, and forwarding the recovery interest packet to the new access node according to the two-dimensional coordinate identifier of the new access node, includes: Traverse the local PIT using the producer namespace prefix as the matching condition; PIT entries that have not received corresponding data packets and have not timed out are selected as the unsatisfied interest entries. A restorative interest package is generated based on the unmet interest items, and the restorative interest package is set with a nonce different from that of the original interest package corresponding to the unmet interest items; The restorative interest packet is forwarded to the new access node based on the two-dimensional coordinate identifier of the new access node; After completing the restorative interest packet re-expression corresponding to the producer namespace prefix, the restorative flag position corresponding to the producer namespace prefix in the mobile binding table is set to the restored state.

6. The data plane forwarding enhancement method for ubiquitous network producer mobility according to claim 1, characterized in that, The new arrival interest packets matching the producer namespace prefix are forwarded to the new access node according to the two-dimensional coordinate identifier of the new access node, including: Query the mobile binding table at the old access node; When the name prefix of the newly arrived interest packet matches the prefix of the producer namespace, and the corresponding mobile binding entry is determined to be in the valid period of proxy forwarding mode according to the proxy status validity information, the forwarding of the newly arrived interest packet according to the old access node local delivery path is stopped. The PIT entry corresponding to the newly arrived interest packet is maintained according to the named data network forwarding process, and the next-hop forwarding interface is selected based on the two-dimensional coordinate identifier of the new access node.

7. The data plane forwarding enhancement method for ubiquitous network producer mobility according to claim 1, characterized in that, The recovering interest packet or the newly arriving interest packet is an interest packet to be forwarded. The two-dimensional coordinate identifier includes the orbital plane number and the satellite's number within the orbital plane. Forwarding the interest packet to be forwarded to the new access node according to the two-dimensional coordinate identifier of the new access node includes: Obtain the two-dimensional coordinate identifier of the current forwarding node, and compare the deviations between the two-dimensional coordinate identifier of the current forwarding node and the two-dimensional coordinate identifier of the newly accessed node in terms of orbital plane sequence number and satellite sequence number within the orbital plane; When the orbital plane number in the two-dimensional coordinate identifier of the current forwarding node is not equal to the orbital plane number in the two-dimensional coordinate identifier of the new access node, the adjacent node that can make the orbital plane number move closer to the new access node is selected as the next hop. When the orbital plane number in the two-dimensional coordinate identifier of the current forwarding node is equal to the orbital plane number in the two-dimensional coordinate identifier of the new access node, and the satellite's orbital plane number in the two-dimensional coordinate identifier of the current forwarding node is not equal to the satellite's orbital plane number in the two-dimensional coordinate identifier of the new access node, the adjacent node that can make the satellite's orbital plane number move closer to the new access node is selected as the next hop. When the two-dimensional coordinate identifier of the current forwarding node is the same as that of the new access node, the interest packet to be forwarded is handed over to the new access node for producer access link forwarding processing.

8. The data plane forwarding enhancement method for ubiquitous network producer mobility according to claim 1, characterized in that, The new access node forwards the received recovery interest packet or the newly arrived interest packet to the producer via the producer access link, and sends back the data packet returned by the producer based on the PIT record formed during the forwarding process, including: The new access node determines the corresponding producer access link based on the producer namespace prefix; The producer access link forwards the restorative interest packet or the newly arrived interest packet to the producer. The data packets returned by the producer are received, and the data packets are transmitted back hop by hop according to the PIT records formed during the forwarding process of the recovering interest packets or the newly arrived interest packets.

9. The data plane forwarding enhancement method for ubiquitous network producer mobility according to claim 1, characterized in that, During route convergence, intermediate forwarding nodes determine whether the optimal outgoing interface of the arriving interest packet coincides with the incoming interface based on the updated FIB. If they coincide, a NACK packet is returned to the previous hop forwarding node corresponding to the incoming interface, causing the previous hop forwarding node to rewrite the arriving interest packet based on the updated FIB. This includes: The intermediate forwarding node queries the updated FIB based on the name prefix of the arriving interest packet to determine the optimal outgoing interface of the arriving interest packet; When the optimal outgoing interface coincides with the incoming interface of the arriving interest packet, delete or invalidate the local PIT entry corresponding to the arriving interest packet. The intermediate forwarding node returns a NACK packet corresponding to the arriving interest packet to the previous hop forwarding node corresponding to the ingress interface; After receiving the NACK packet, the previous hop forwarding node reselects the outgoing interface based on the updated FIB and re-expresses the arriving interest packet.

10. The data plane forwarding enhancement method for ubiquitous network producer mobility according to claim 2, characterized in that, After the proxy state expires, the old access node cleans up the mobile binding entries corresponding to the producer namespace prefix, including: Delete or invalidate the two-dimensional coordinate identifier of the new access node, the agent status expiration time, and the recovery flag corresponding to the producer namespace prefix; Restore the producer's mobile working mode from the proxy forwarding mode to the normal forwarding mode; This enables subsequent interest packets matching the producer's namespace prefix to be forwarded via the normal named data network according to the updated FIB.

Images