Refined Assured Forwarding Framework for Differentiated Services Architecture

• US 20080080382A1
• Filed: 09/28/2007
• Published: 04/03/2008
• Est. Priority Date: 09/28/2006
• Status: Abandoned Application

• Current Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Original Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Inventors: Sluss, James, Dahshan, Mostafa, Verma, Pramode
• Application Number:
  US11/864,311
• Publication Number:
  US 20080080382A1
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04L 45/302 Route determination based on requested QoS
• CPC Class Codes: H04L 45/56 Routing software
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2408 for supporting different services, e.g. a differentiated services [DiffServ] type of service
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/6215 Individual queue per QOS, rate or priority
• CPC Class Codes: H04L 47/623 Weighted service order

Abstract

The DiffServ architecture is an increasingly preferred approach for providing varying levels of Quality of Service in an IP network. This discovery presents a new framework for improving the performance of the DiffServ architecture where heterogeneous traffic flows share the same aggregate class. The new framework requires minimal modification to existing DiffServ routers by adding a second layer of classification of flows based on their average packet sizes and using Weighted Fair Queueing for flow scheduling. The efficiency of the new framework is demonstrated by simulation results for delay, packet delivery, throughput, and packet loss, under different traffic scenarios.

Claims

1. A method of controlling the order of packets forwarded by an edge router, the method comprising the steps of:

receiving packets from a network;

assigning the packets into an assured forwarding class; and

separating the packets of the assured forwarding class into subclasses such that the packets in each subclass have a comparable characteristic.

2. The method of claim 1, wherein in the step of separating, the comparable characteristic is the length of the packets.

3. The method of claim 2, wherein the length of the packets is defined further as the number of bytes in the packet.

4. The method of claim 1, further comprising the step of:

forwarding the packets within the subclasses such that more packets are forwarded from one subclass relative to another subclass.

5. The method of claim 4, wherein in the step of separating, the comparable characteristic is the length of the packets.

6. The method of claim 5, wherein the packets include bytes and also wherein equal numbers of bytes are forwarded from each subclass whereby a subclass having shorter packets forwards a larger number of packets.

12. The method of claim 11, wherein the packets include bytes and also wherein the conditioner is adapted to forward equal numbers of bytes from each subclass whereby a subclass having shorter packets forwards a larger number of packets.

Note:

claims 13-24 are similar to claim 1, except there are at least two assured forwarding classes.

7. An edge router to control the order of processing packets, comprising:

an input port adapted to receive packets from a first network;

an AF classifier adaped to assign the packets into an assured forwarding class; and

an RAF refiner/subclassifier adapted to assign the packets into subclasses such that the packets in each subclass have a comparable characteristic.

8. The edge router of claim 7, wherein the comparable characteristic is the length of the packets.

9. The edge router of claim 8, wherein the length of the packets is defined further as the average packet length.

10. The edge router of claim 7, further comprising:

a conditioner adapted to forward the packets within the subclasses such that more packets are forwarded from one subclass relative to another subclass.

11. The method of claim 10, the comparable characteristic is the length of the packets.

13. A method of controlling the order of packets forwarded by an edge router, the method comprising the steps of:

receiving packets from a network;

assigning the packets into a plurality of assured forwarding classes where the assured forwarding classes have different levels of service; and

for at least two of the assured forwarding classes;

separating the packets of the assured forwarding class into subclasses such that the packets in each subclass have a comparable characteristic.

14. The method of claim 13, wherein in the step of separating, the comparable characteristic is the length of the packets.

15. The method of claim 14, wherein the length of the packets is defined further as the average packet length.

16. The method of claim 13, further comprising the step of:

forwarding the packets within the subclasses for the at least two AF classes such that more packets within one subclass of an AF class are forwarded relative to another subclass within the same AF class.

17. The method of claim 16, wherein in the step of separating, the comparable characteristic is the length of the packets.

18. The method of claim 17, wherein the packets include bytes and also wherein equal numbers of bytes are forwarded from each subclass whereby a subclass having shorter packets forwards a larger number of packets.

19. An edge router to control the order of processing packets, comprising:

an input port adapted to receive packets from a first network;

an AF classifier adaped to assign the packets into at least two assured forwarding classes; and

an RAF refiner/subclassifier adapted to assign the packets into subclasses for each of the at least two assured forwarding classes such that the packets in each subclass within an assured forwarding class have a comparable characteristic.

20. The edge router of claim 19, wherein the comparable characteristic is the length of the packets.

21. The edge router of claim 20, wherein the length of the packets is defined further as the average packet length.

22. The edge router of claim 19, further comprising:

a conditioner adapted to forward the packets within the subclasses such that more packets are forwarded from one subclass of an assured forwarding class relative to another subclass within the same assured forwarding class.

23. The method of claim 22, the comparable characteristic is the length of the packets.

24. The method of claim 23, wherein the packets include bytes and also wherein the conditioner is adapted to forward equal numbers of bytes from each subclass whereby a subclass having shorter packets forwards a larger number of packets.