Dynamic traffic conditioning

• US 6,028,842 A
• Filed: 12/23/1996
• Issued: 02/22/2000
• Est. Priority Date: 12/23/1996
• Status: Expired due to Term

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Corporation
• Inventors: Kung, Hsiang-Tsung, Chapman, Alan Stanley John
• Primary Examiner(s): NGO, RICKY QUOC
• Application Number:
  US08/772,256
• Time in Patent Office: 1,156 Days
• Field of Search: 370/230, 370/235, 370/252, 370/389, 370/400, 370/401, 370/412, 370/465, 370/468, 370/437, 395/200.53, 395/200.54, 395/200.55, 395/200.56, 395/200.7, 709/223, 709/224, 709/226, 709/238, 709/249, 709/250
• US Class Current: 370/235
• CPC Class Codes: H04L 2012/5632 Bandwidth allocation
• CPC Class Codes: H04L 2012/5638 Services, e.g. multimedia, GOS, QOS
• CPC Class Codes: H04L 2012/564 Connection-oriented
• CPC Class Codes: H04L 2012/5645 Connectionless
• CPC Class Codes: H04L 2012/5651 Priority, marking, classes
• CPC Class Codes: H04L 2012/5667 IP over ATM
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

Multi-media networks will require that a data flow be given certain quality-of-service (QOS) for a network connection but pre-negotiation of this sort is foreign to the current data networking model. The real time traffic flow in the data network requires distinct limits on the tolerance to delay, and the variations in that delay. Interactive voice and video demand that the total delay does not exceed the threshold beyond which human interaction is unacceptably impaired. The present invention allows the network to discover the nature of the service for each traffic flow, classifies it dynamically, and exercises traffic conditioning by means of such techniques as admission control and scheduling when delivering the traffic downstream to support the service appropriately.

Claims

1. In a packet data network for multimedia traffic having one or more nodes, a method of dynamically conditioning at a node a digital flow of traffic comprising steps of:

continuously monitoring the digital flow of traffic at the node as to its real time flow characteristics; and

reclassifying locally at the node in real time the digital flow of traffic from one class into another among a plurality of classes according to preset criteria based on real time flow characteristics and on protocol types, said plurality of classes specifying respective levels of the quality of service with which to condition the digital flow of traffic for delivery downstream and the protocol types being TCP and UDP.

2. The method according to claim 1 wherein the step of reclassifying comprises a step of classifying into two default classes, TCP interactive and UDP low latency.

3. The method according to claim 2 comprising a further step of:

changing the TCP interactive class to one or the other of TCP bulk guaranteed and TCP bulk best effort.

4. The method according to claim 2 comprising a further step of:

changing the UDP low latency class to one or the other of UDP real time and UDP bulk best effort.

5. The method according to claim 3 comprising a further step of:

delivering downstream the digital flow of traffic according to the quality of service specified by said one of said plurality of classes.

6. The method according to claim 4 comprising a further step of:

delivering downstream the digital flow of traffic according to the quality of service specified by said one of said plurality of classes.

7. The method according to claim 5 wherein one of the preset criteria is the length of packets in the digital flow of traffic.

8. The method according to claim 6 wherein one of the preset criteria is the length of packets in the digital flow of traffic.

9. The method according to claim 5 wherein one of the preset criteria is the number of consecutive packets in the digital flow of traffic.

10. The method according to claim 6 wherein one of the preset criteria is the number of consecutive packets in the digital flow of traffic.

11. The method according to claim 1 wherein the quality of service is expressed by a plurality of parameters which include a priority level of delivery of the digital flow of traffic and a bandwidth assigned to the digital flow of traffic.

12. The method according to claim 1 comprising a further step of:

informing one or more downstream nodes the results of monitoring and classifying.

13. The method according to claim 12 wherein the step of informing comprises a step of:

propagating information relevant to the results in a packet which is inserted into the digital flow of traffic.

14. In a packet data network for multimedia traffic having one or more nodes, a method of dynamically conditioning at a source host a digital flow of traffic comprising steps of:

continuously monitoring the digital flow of traffic as to its real time flow characteristics at the source host from which the digital flow of traffic is generated; and

reclassifying, in real time locally at the source host, the digital flow of traffic from one class into another among a plurality of classes according to preset criteria based on real time flow characteristics and on protocol types, said plurality of classes specifying respective levels of the quality of service with which to condition the digital flow of traffic for delivery downstream and the protocol types being TCP and UDP.

15. The method according to claim 14 comprising a further step of:

delivering downstream the digital flow of traffic according to the quality of service specified by said one of said plurality of classes.

16. The method according to claim 15 comprising a further step of:

informing one or more downstream nodes the results of monitoring and classifying.

17. The method according to claim 16 wherein the step of informing comprises a step of:

propagating downstream information relevant to the results.

18. In a packet data network for multimedia traffic having one or more nodes, a method of dynamically conditioning at a node a digital flow of traffic comprising steps of:

continuously monitoring real time flow characteristics at the node to detect a real time digital traffic flow;

determining if the real time digital traffic flow can be admitted for delivery downstream, based on an available bandwidth for the real time digital traffic flow; and

reclassifying locally at the node the real time traffic flow from one class into a different class among a plurality of classes for conditioning according to preset criteria based on real time flow characteristics and on protocol types, said preset criteria specifying a level of the quality of service required by said different class for delivery downstream and the protocol types being TCP and UDP.

19. The method according to claim 18 wherein the step of continuously monitoring the digital flow of traffic further comprises a step of:

monitoring the characteristics of the growth of a queue at the node into which the digital flow of traffic is stored for delivery.

20. The method according to claim 18 wherein the step of continuously monitoring the digital flow of traffic comprises further a step of:

monitoring a history of interarrival times for packets of the digital flow of traffic.

21. The method according to claim 20 comprising further steps of:

recording a first count for the arrival times below a preset threshold;

recording a second count for the arrival times above the threshold; and

determining the digital flow of traffic as being a real time traffic flow unless the first count is more than the second count by a predetermined amount.

22. The method according to claim 18 wherein the quality of service is expressed by a plurality of parameters which include a priority level of delivery of the digital flow of traffic and a bandwidth assigned to the digital flow of traffic.

23. The method according to claim 18 comprising a further step of:

informing one or more downstream nodes the results of monitoring and classifying.

24. The method according to claim 23 wherein the step of informing comprises a step of:

propagating information relevant to the results in a packet which is inserted into the digital flow of traffic.