Active queue management system

Abstract

There is herein described a method of active queue management for use in a telecommunications system comprising a Customer Premises Equipment (CPE) and a network access point, the network access point being adapted to transmit one or more data packets to the CPE, wherein the CPE comprises a plurality of packet queues, each of the plurality of packet queues being capable of holding data packets received from the network access point, the method comprising transmitting queue management information from the CPE to the network access point, where the queue management information enables the determination of a most suitable one of the plurality of packet queues for receiving a data packet, determining, using the transmitted queue management information, the most suitable one of the plurality of packet queues for receiving a data packet to be transmitted from the network access point to the CPE.

Description

[0001] Active Queue Management System

[0002] Active Queue Management (AQM) is typically performed on traffic in broadband networks. In particular, data packets transmitted from a network access point to customer premises equipment (CPE) are placed in queues prior to transmission. Which queue the packet is placed in depends on the priority that the particular customer places on different types of packet. In an example there are three queues: high, medium and low priority. Voice packets are placed in the high priority queue, data packets are placed in the medium priority queue, and video packets are placed in the low priority queue. The packets are transmitted in order of priority to the CPE. When the packets reach the CPE they are placed in corresponding queues (“peer queues”).

[0003] The parameters governing AQM vary from one customer to another. An HQoS (Hierarchical Quality of Service) profile containing the relevant parameters is established for each customer. These profiles are stored in a Subscriber Profile / Policy block on a RADIUS server and are updated periodically when a customer’s needs change. When updated, the server sends the updated parameters to the network access point, which updates its packet scheduling algorithm with the new parameters.

[0004] This system is inflexible and can result in a relatively poor quality of service.

[0005] It would be desirable to overcome and / or substantially mitigate some or all of the above- mentioned and / or other disadvantages of the prior art.

[0006] According to a first aspect of the invention there is provided a method of active queue management for use in a telecommunications system comprising a Customer Premises Equipment (CPE) and a network access point, the network access point being adapted to transmit one or more data packets to the CPE, wherein the CPE comprises a plurality of packet queues, each of the plurality of packet queues being capable of holding data packets received from the network access point, the method comprising: transmitting queue management information from the CPE to the network access point, where the queue management information enables the determination of a most suitable one of the plurality of packet queues for receiving a data packet, determining, using the transmitted queue management information, the most suitable one of the plurality of packet queues for receiving a data packet to be transmitted from the network access point to the CPE.

[0007] Embodiments of the invention enable an AQM method in which feedback is provided from the CPE to the network access point, enabling a higher quality of service to be provided.

[0008] The CPE may be adapted to transmit one or more data packets to the network access point. The network access point may comprise a plurality of packet queues, each of the plurality of packet queues being capable of holding data packets received from the CPE. The method may further comprise transmitting queue management information from the network access point to the CPE, where the queue management information enables the determination of a most suitable one of the plurality of packet queues for receiving a data packet. The method may further comprise determining, using the transmitted queue management information, the most suitable one of the plurality of packet queues for receiving a data packet to be transmitted from the CPE to the network access point.

[0009] The method may further comprise transmitting the data packet from the network access point to the determined one of the plurality of packet queues. The network access point may be a Broadband Network Gateway (BNG).

[0010] The step of transmitting queue management information may comprise encapsulating a data packet to impose an iOAM header shim on the data packet, where the iOAM header shim contains the queue management information. The method may further comprise transmitting the encapsulated data packet. The method may further comprise receiving the transmitted encapsulated data packet and may comprise de-encapsulating the data packet and extracting the queue management information.

[0011] The queue management information may comprise values for latency, jitter and buffer depth associated with one or more packet queues. The queue management information may be input into an AQM algorithm block. The AQM algorithm block may further receive subscriber information as an input. The subscriber information may be received by the network access point from an external server. The AQM algorithm block may process the queue management information and / or subscriber information and may output queue management parameters. The queue management parameters may relate to the classification and / or marking and / or policing and / or queue selection and / / or queue scheduling of one or more data packets to be transmitted to the CPE.

[0012] The step of determining, using the transmitted queue management information, an appropriate one of the plurality of packet queues as most suitable for receiving a data packet to be transmitted may be performed by each of the one or more policy registers.

[0013] According to a further aspect of the invention there is provided a method of active queue management for use in a telecommunications system comprising a Customer Premises Equipment (CPE) and a network access point, the CPE being adapted to transmit one or more data packets to the network access point, wherein the network access point comprises a plurality of packet queues, each of the plurality of packet queues being capable of holding data packets received from the CPE, the method comprising: transmitting queue management information from the network access point to the CPE, where the queue management information enables the determination of a most suitable one of the plurality of packet queues for receiving a data packet, determining, using the transmitted queue management information, the most suitable one of the plurality of packet queues for receiving a data packet to be transmitted from the CPE to the network access point.

[0014] The network access point may be adapted to transmit one or more data packets to the CPE. The CPE may comprise a plurality of packet queues, each of the plurality of packet queues being capable of holding data packets received from the network access point. The method may further comprise transmitting queue management information from the CPE to the network access point, where the queue management information enables the determination of a most suitable one of the plurality of packet queues for receiving a data packet. The method may further comprise determining, using the transmitted queue management information, the most suitable one of the plurality of packet queues for receiving a data packet to be transmitted from the network access point to the CPE.

[0015] It is to be understood that the features above given in relation to the first aspect of the invention are also applicable to the second aspect of the invention. An embodiment of the invention will now be described in detail, for illustration only, with reference to the appended drawings, in which:

[0016] Fig 1 is a schematic view of an arrangement according to the prior art;

[0017] Fig 2 is a flow chart showing a method according to an embodiment of the invention;

[0018] Fig 3 is a schematic view of an arrangement according to an embodiment of the invention;

[0019] Fig 4 is a flow chart showing a method according to a further embodiment of the invention.

[0020] Fig 1 is a schematic view of an arrangement according to the prior art. In particular, there is Customer Premises Equipment (CPE) 1 which is connected by optical fibre (not shown) to an Optical Line Terminal (OLT). The OLT is omitted from Fig 1 for clarity. The OLT connects by optical fibre to a Broadband Network Gateway (BNG) 2. The BNG 2 is a network access point. The CPE 1 contains an AQM algorithm block 4 which is connected to m queues 5. The m queues 5 comprise packets that have been received by, and packets that are to be transmitted by, the CPE 1.

[0021] The BNG 2 contains an AQM algorithm block 6 which is connected to n queues 7. The n queues 7 comprise packets that have been received by, and packets that are to be transmitted by, the BNG 2.

[0022] A RADIUS server 8 is also provided. The RADIUS server 8 contains a Subscriber Profile / Policy block 3. The Subscriber Profile / Policy block 3 connects to the AQM algorithm block 4 in the CPE 1 and to the AQM algorithm block 6 in the BNG 2.

[0023] Fig 2 is a flow chart showing a method in accordance with the prior art. In particular, at step s21 , the AQM algorithm block 6 at Broadband Network Gateway (BNG) 6 receives subscriber information associated with a Customer Premises Equipment (CPE) 1 from a Subscriber Profile / Policy block 3 at RADIUS server 8.

[0024] At step s22, the AQM algorithm block 6 processes the subscriber information. At step s23, the AQM algorithm block 6 outputs parameters pertinent to the processes of classification, marking, policing, queue selection and queue scheduling carried out at the BNG 2.

[0025] At step s24, the AQM algorithm block 6 writes the output parameters to the scheduling algorithms and other queue-management functions of the BNG 2.

[0026] At step s25, using the output parameters, the queue-management functions of the BNG 2 perform queue management of packets sent from the BNG 2 to the CPE 1.

[0027] At step s26, the subscriber information held at the Subscriber Profile / Policy block 3 at RADIUS server 8 is modified. This occurs periodically. Once it has occurred the process returns to step s21 , i.e. the AQM algorithm block 6 at Broadband Network Gateway (BNG) 6 receives the modified subscriber information associated with the Customer Premises Equipment (CPE) 1 from the Subscriber Profile / Policy block 3. The process continues using the modified subscriber information.

[0028] This is an example of an open-loop queue management system. In this system the BNG does not receive feedback from the CPE, nor does the CPE receive feedback from the BNG.

[0029] Fig 3 is a schematic view of an arrangement according to an embodiment of the invention. In particular, there is a Customer Premises Equipment (CPE) 21 which is connected by optical fibre (not shown) to an Optical Line Terminal (OLT). The OLT is omitted for clarity. The OLT connects by optical fibre to a Broadband Network Gateway (BNG) 22. The CPE 21 contains an AQM algorithm block 24 which is connected to m queues 25. The m queues 25 comprise packets that have been received by, and packets that are to be transmitted by, the CPE 21.

[0030] The BNG 22 contains an AQM algorithm block 26 which is connected to n queues 27. The n queues 27 comprise packets that have been received by, and packets that are to be transmitted by, the BNG 22. A RADIUS server 28 is also provided. The RADIUS server 28 contains a Subscriber Profile / Policy block 23. The Subscriber Profile / Policy block 23 connects to the AQM algorithm block 24 in the CPE 21 and to the AQM algorithm block 26 in the BNG 22.

[0031] Fig 4 is a flow chart showing a method in accordance with an embodiment of the invention. In particular, at step s41 , at Customer Premises Equipment (CPE) 21 a packet is encapsulated with an iOAM header shim containing latency, jitter, buffer depth and other parameters.

[0032] At step s42, the packet is transmitted from the CPE 21 to a Broadband Network Gateway (BNG) 22.

[0033] At step s43, the packet is de-encapsulated and the information in the iOAM is read by an AQM algorithm block 26 located at the BNG 22.

[0034] At step s44, the AQM algorithm block 26 at the BNG 22 receives subscriber information associated with the CPE 21 from a RADIUS server 28.

[0035] At step s45, the AQM algorithm block 26 processes the iOAM information and subscriber information.

[0036] At step s46, the AQM algorithm block 26 outputs parameters pertinent to the processes of classification, marking, policing, queue selection and queue scheduling carried out at the BNG 22.

[0037] At step s47, the AQM algorithm block 26 writes the output parameters to the scheduling algorithms and other queue-management functions of the BNG 22.

[0038] At step s48, using the output parameters, the queue-management functions of the BNG perform queue management of packets sent from the BNG 22 to the CPE 21 , selecting the most suitable queue from queues Q1-Qn 27 in which to place the packets. In one example, queue Q3 is selected for a particular packet.

[0039] At step s49, at the BNG 22, the packet is encapsulated with an iOAM header shim containing latency, jitter, buffer depth and other parameters. At step s50, the packet is placed in Q3 of the BNG 22 and then transmitted to Q’3 at CPE 21. Q’3 is the peer queue of Q3.

[0040] At step s51 , the packet is de-encapsulated and the information in the iOAM is read by an AQM’ algorithm block 24 located at the CPE 21.

[0041] At step s52, the AQM’ algorithm block 24 at the CPE 21 receives subscriber information associated with the CPE 21 from a RADIUS server 28.

[0042] At step s53, the AQM’ algorithm block 24 processes the iOAM information and subscriber information.

[0043] At step s54, the AQM’ algorithm block 24 outputs parameters pertinent to the processes of classification, marking, policing, queue selection and queue scheduling carried out at the CPE 21.

[0044] At step s55, the AQM algorithm block 24 writes the output parameters to the scheduling algorithms and other queue-management functions of the CPE 21 .

[0045] At step s56, using the output parameters, the queue-management functions of the CPE 21 perform queue management of packets sent from the CPE 21 to the BNG 22, selecting the most suitable queue in which to place the packet prior to its transmission to BNG 22. The process then returns to step s41.

Claims

Claims1. A method of active queue management for use in a telecommunications system comprising a Customer Premises Equipment (CPE) and a network access point, the network access point being adapted to transmit one or more data packets to the CPE, wherein the CPE comprises a plurality of packet queues, each of the plurality of packet queues being capable of holding data packets received from the network access point, the method comprising: transmitting queue management information from the CPE to the network access point, where the queue management information enables the determination of a most suitable one of the plurality of packet queues for receiving a data packet, determining, using the transmitted queue management information, the most suitable one of the plurality of packet queues for receiving a data packet to be transmitted from the network access point to the CPE.

2. A method of active queue management for use in a telecommunications system comprising a Customer Premises Equipment (CPE) and a network access point, the CPE being adapted to transmit one or more data packets to the network access point, wherein the network access point comprises a plurality of packet queues, each of the plurality of packet queues being capable of holding data packets received from the CPE, the method comprising: transmitting queue management information from the network access point to the CPE, where the queue management information enables the determination of a most suitable one of the plurality of packet queues for receiving a data packet, determining, using the transmitted queue management information, the most suitable one of the plurality of packet queues for receiving a data packet to be transmitted from the CPE to the network access point.

3. A method as claimed in claim 1 or claim 2, wherein the method further comprises transmitting the data packet from the network access point to the determined most suitable one of the plurality of packet queues.

4. A method as claimed in any preceding claim, wherein the network access point is a Broadband Network Gateway.

5. A method as claimed in any preceding claim, wherein the queue management information comprises values for latency, jitter and buffer depth associated with one or more packet queues.

6. A method as claimed in any preceding claim, wherein the step of transmitting queue management information comprises encapsulating a data packet to impose an iOAM header shim on the data packet, where the iOAM header shim contains the queue management information.

7. A method as claimed in claim 6, wherein the method further comprises transmitting the encapsulated data packet.

8. A method as claimed in any preceding claim, wherein the method further comprises receiving and de-encapsulating the transmitted data packet and extracting the queue management information.

9. A method as claimed in any preceding claim, wherein the queue management information from the received data packet is processed to produce queue management parameters relating to the classification and / or marking and / or policing and / or queue selection and / or queue scheduling of one or more data packets to be transmitted.

10. A method as claimed in any preceding claim, wherein the step of determining, using the transmitted queue management information, an appropriate one of the plurality of packet queues as most suitable for receiving a data packet to be transmitted is performed by each of one or more policy registers.

11. A computer-readable carrier medium comprising a computer program, which, when the computer program is executed by a computer, causes the computer to carry out the steps of any one of the preceding claims.

12. A computer programmed to carry out the steps of any of claim 1 to claim 10.

Images