Arrangement and method relating to packet flow control

• US 6,212,162 B1
• Filed: 05/07/1998
• Issued: 04/03/2001
• Est. Priority Date: 11/09/1995
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Horlin, Dan
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): Tran, Maikhanh
• Application Number:
  US09/073,821
• Time in Patent Office: 1,062 Days
• Field of Search: 370/412, 370/414, 370/415, 370/416, 370/417, 370/418, 370/229, 370/230-231, 370/232, 370/236, 370/468, 370/395, 370/398
• US Class Current: 370/229
• CPC Class Codes: H04L 12/5602 Bandwidth control in ATM Networks, e.g. leaky bucket
• CPC Class Codes: H04L 2012/5632 Bandwidth allocation
• CPC Class Codes: H04L 2012/5651 Priority, marking, classes
• CPC Class Codes: H04L 49/205 Quality of Service based
• CPC Class Codes: H04L 49/25 Routing or path finding in a switch fabric
• CPC Class Codes: H04L 49/30 Peripheral units, e.g. input or output ports
• CPC Class Codes: H04L 49/3081 ATM peripheral units, e.g. policing, insertion or extraction
• CPC Class Codes: H04L 49/50 Overload detection or protection within a single switching element

Abstract

An arrangement and a method control the flow of signals including a number of information packets in a communications network, e.g. an ATM-network. The arrangement includes a device for separating the signals in the first traffic signals and second traffic signals. The first traffic signals are signals that have a higher proportion of guaranteed resources, i.e. bandwidth, than the second traffic signals. The first traffic signals are also given a lower priority than the second traffic signals. The first and second traffic signals are handled separately.

Claims

1. An arrangement for controlling the flow of signals comprising a number of information packets in a communications network, said arrangement comprising

means for separating the signals in at least first traffic signals and second traffic signals, wherein the first traffic signals are signals having a higher proportion of guaranteed resources than the second traffic signals,

means for handling the flow control of at least one of the first and second traffic signals separately from the flow control of the other traffic signal(s), wherein the first traffic signals are given a lower priority than the second traffic signals, and

means for monitoring the cellrate of said second signals.

2. The arrangement of claim 1, wherein the first traffic signals are signals having a significant proportion of guaranteed bandwidth.

3. The arrangement of claim 1, wherein a traffic stream comprising traffic signals having a lower proportion of packets that are guaranteed resources have a higher priority.

4. The arrangement of claim 3, further comprising a buffering arrangement in which packets can be arranged in at least one queue.

5. The arrangement of claim 4, wherein the buffering arrangement at least comprises a first buffering area in which low priority packets can be stored.

6. The arrangement of claim 5, wherein packets originating from terminals having different QoS are arranged in a number of different queues, at least depending on QoS, in the buffering arrangement.

7. The arrangement of claim 6, wherein a queue arranging means arranges the packets of the traffic streams in the buffering arrangement depending on at least QoS and on proportion of guaranteed bandwidth and wherein packets can be arranged in different buffering areas even if they have the same QoS.

8. The arrangement of claim 4, further comprising monitoring means for measuring the cellrate of signals having a high priority and

means for monitoring the queue status in buffer areas for signals having a lower priority, thus providing first and second flow control signals to be used for flow controlling purposes.

9. The arrangement of claim 1, wherein cell credit flow control is combined with cellrate flow control for maximizing the use of link capacity without causing link congestion.

10. The arrangement of claim 6, wherein the buffering arrangement and the queue arranging means are implemented at the input unit and the corresponding input buffering means of a switch core.

11. The arrangement of claim 1, wherein the signals comprise asynchronous transfer mode (ATM) cells, the arrangement thus operating in ATM-mode.

12. The arrangement of claim 11, wherein at least some of the signals are available bit rate (ABR) signals.

13. The arrangement of claim 1, further comprising a virtual flow controlling element arranged internally in a network comprising a virtual source end system and a virtual destination end system.

14. A switching arrangement for switching information packets incoming to at least one inlet unit on a number of input links through a switch core on to a number of output links, said arrangement comprising:

means for separating incoming packets into at least a first and second traffic stream, wherein the first traffic stream comprises a higher proportion of packets guaranteed resources than the second traffic stream, the flow control of at least one of said traffic streams being handled separately from the other traffic stream(s), the packets of said first traffic stream are given a lower priority than the second traffic signals, and

means for monitoring the cellrate of said second traffic stream.

15. The arrangement of claim 14, wherein the first traffic stream comprises signals having a significant proportion of guaranteed bandwidth.

16. The arrangement of claim 14, wherein traffic streams comprising signals having a higher proportion of packets that are guaranteed resources have a lower priority whereas the traffic stream having the lowest proportion packets guaranteed bandwidth is given the highest priority.

17. The arrangement of claim 14, wherein the packets incoming from terminals having different QoS are arranged in different queues, at least depending on QoS, in an input buffering unit by queue arranging means, said queue arranging means furthermore arranging the packets of the traffic streams in the buffering arrangement depending on the proportion of guaranteed bandwidth.

18. The arrangement of claim 17, wherein signals of the same QoS are arranged in different queues depending on whether having a significant portion of guaranteed bandwidth or not.

19. The arrangement of claim 18, wherein the buffering handling of said first and second traffic streams is separate and/or different and wherein a first buffering area of the input buffering unit is used for buffering traffic signals having a lower priority.

20. The arrangement of claim 19, wherein first flow control signals relating to cellrate measurement on signals having a high priority and second flow control signals relating to queue status in buffers for signals given a lower priority are provided to the destination arrangement, and they are used for flow controlling purposes with the use of resource management cells sent by said destination arrangement to the sending arrangements.

21. The arrangement of claim 15, wherein it operates in asynchronous transfer mode (ATM) and at least some signals comprise available bit rate (ABR) signals.

22. An arrangement for controlling the flow of information packets in a communications system, comprising:

means for separating streams of packets having a proportion of packets being guaranteed bandwidth exceeding a given value, thus at least providing first and second traffic streams,

means for measuring the cellrate of said second packet streams,

buffering means for temporarily storing packets of said first traffic streams separately from said second traffic stream packets,

means for measuring the fullness of said buffering means, and

means for feeding back the cellrate measurement results and cell credit measurement results relating to buffering fullness to the sending sources/system(s) for controlling the flow, wherein a higher priority is given to said second packets.

23. The arrangement of claim 22, wherein the streams of packets are at least to some extent asynchronous transfer mode (ATM), available bit rate (ABR) signals and wherein the capacity on output links via the controlling is maximally exploited.

24. The arrangement of claim 22, wherein the sending system is a virtual sending end system.

25. The arrangement of claim 23, wherein the sending system is a real source end system, the arrangement further comprising a converting arrangement for converting queue status measurement results into available bit rate (ABR) explicit rate parameters for modifying resource management cells which are fed back to the real source end system.

26. A system for controlling the flow of cells from a source end system to a destination end system through a network comprising a number of real nodes and a number of virtual nodes, wherein

at least a number of the nodes comprise(s) means for separating first signals having at least a given proportion of guaranteed bandwidth from second signals having not, buffering means for temporarily storing at least the first signals and monitoring means for measuring the queue status for said first signals and for measuring the cellrate of said second signals and feeding back the results of said measurements to a preceding sending source to control the transmission of signals.

27. A method of controlling the flow of signals in the form of information packets incoming on a number of input links, comprising the steps of:

separating the signals at least into first signals having a proportion of guaranteed bandwidth exceeding a given threshold value from second signals thus providing at least first and second signals respectively,

controlling the flow of said first signals separately from said second signals through feeding results about measurements on said first and second signals respectively to sending sources, and

giving priority to said second signals having a lower proportion of guaranteed bandwidth.

28. The method of claim 27, further comprising the step of:

storing said first signals separately from said second signals in buffering means for said first signals.

29. The method of claim 28, further comprising the steps of:

carrying out cellrate measurements on said first signals,

measuring the buffering status of the queues of the buffering area intended for said first signals,

converting the latter results into available bit rate (ABR) explicit rate parameters, and

feeding the results back to an originating real end source.

30. The method of claim 27, wherein the signals having different proportions of guaranteed bandwidth are signals of one and the same service class.