Rate-based adaptive congestion control system and method for integrated packet networks

• US 5,426,640 A
• Filed: 01/21/1992
• Issued: 06/20/1995
• Est. Priority Date: 01/21/1992
• Status: Expired due to Term

• Current Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Original Assignee: Codex Corporation
• Inventors: Hluchyj, Michael G., Yin, Nanying, Grossman, Daniel B.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Patel, Ajit
• Application Number:
  US07/823,724
• Time in Patent Office: 1,246 Days
• Field of Search: 370/94.1, 370/60, 370/94.2, 370/79, 370/60.1, 370/13, 370/17, 370/94.3, 370/58.1-58.3, 340/825.02, 340/825.06
• US Class Current: 370/235
• CPC Class Codes: H04L 12/5602 Bandwidth control in ATM Networks, e.g. leaky bucket
• CPC Class Codes: H04L 2012/563 Signalling, e.g. protocols, reference model
• CPC Class Codes: H04L 2012/5635 Backpressure, e.g. for ABR
• CPC Class Codes: H04L 2012/5636 Monitoring or policing, e.g. compliance with allocated rate, corrective actions
• CPC Class Codes: H04L 2012/5637 Leaky Buckets
• CPC Class Codes: H04L 2012/5646 Cell characteristics, e.g. loss, delay, jitter, sequence integrity
• CPC Class Codes: H04L 2012/5648 Packet discarding, e.g. EPD, PTD

Abstract

An adaptive congestion control device (600) and method minimize congestion using independent congestion level indicators. The invention allows efficient recovery for an integrated packet network that becomes congested and allows a user to utilize the network on a space-available basis when capacity is available.

Claims

1. A system for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least:

source edge node means, operably coupled to receive the fast packet traffic for transmission over the network, said source edge node means having a predetermined throughput rate, for rate-based monitoring and rate enforcement of the fast packet traffic utilizing a leaky bucket monitor/enforcer means that monitors the fast packet traffic and determines and marks a fast packet discard priority for each fast packet,

transit node means, operably coupled to the source edge node means, having a plurality of intermediate nodes for providing at said intermediate nodes fast packet transmission paths, and

destination edge node means, operably coupled to the transit node means, for providing at least a correlated congestion level and for outputting traffic at a realized throughput rate, such that where fast packets utilize unallocated or unused network capacity, the realized throughput rate of transmitted fast packets exceeds a negotiated throughput rate,

wherein the destination edge node means further includes a backwards correlated congestion level state determiner, i.e., BCCL STATE DET, operably coupled to provide a backwards correlated congestion level, i.e., BCCL, state to the leaky bucket monitor/enforcer means via a control fast packet wherein the transit node means further includes at least congestion-reducing means for determining a transit node queue group, i.e., TNQG, congestion level for fast packets and for discarding fast packets based on said transit node queue group congestion level and on said fast packet discard priority.

2. The system of claim 1 wherein the means for determining a transit node queue group congestion level and for discarding fast packets based on said transit node queue group on said discard priority incorporates hysteresis for state transitions.

3. The system of claim 1 wherein the leaky bucket monitor/enforcer means that provides a fast packet discard priority comprises at least said leaky bucket monitor/enforcer for at least determining and marking said fast packet discard priority such that, when a frame is received in excess of a previously negotiated rate, R, and bucket size, B, the discard priority of a first fast packet comprising said frame is set to `last discarded` and the discard priority of subsequent fast packets is set to `first discarded`.

4. The system of claim 3, further including means for, when said frame is received in excess of a previously negotiated rate R2 and bucket size B2, discarding said frame.

5. The system of claim 1, wherein the transit node means further includes a low pass filter that is operably coupled to provide a measurement to the congestion reducing means, wherein the measurement allows congestion determination of a particular queue.

6. The system of claim 5, wherein the measurement that allows congestion determination of the particular queue is obtained by averaging a sampled queue depth that is input from a queue depth sampler.

7. The system of claim 1 wherein the congestion level field is two bits or an equivalent of two bits.

8. A system for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least;

source edge node means, operably coupled to receive the fast packet traffic for transmission over the network, said source edge node means having a predetermined throughput rate, for rate-based monitoring and rate enforcement of the fast packet traffic utilizing a leaky bucket monitor/enforcer means that monitors the fast packet traffic and determines and marks a fast packet discard priority for each fast packet,

transit node means, operably coupled to the source edge node means, having a plurality of intermediate nodes for providing at said intermediate nodes fast packet transmission paths, and

destination edge node means, operably coupled to the transit node means, for providing at least a correlated congestion level and for outputting traffic at a realized throughput rate, such that where fast packets utilize unallocated or unused network capacity, the realized throughput rate of transmitted fast packets exceeds a negotiated throughput rate,

wherein the destination edge node means further includes a backwards correlated congestion level state determiner, i.e., BCCL STATE DET, operably coupled to provide a backwards correlated congestion level, i.e., BCCL, state to the leaky bucket monitor/enforcer means via a control fast packet further including a frame relay backwards explicit congestion notification, i.e., BECN, marking unit, operably coupled to the BCCL STATE DET, for setting a BECN bit when the backward correlated congestion level is equal to or greater than a predetermined congestion level.

9. A system for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least:

source edge node means, operably coupled to receive the fast packet traffic for transmission over the network, said source edge node means having a predetermined throughput rate, for rate-based monitoring and rate enforcement of the fast packet traffic utilizing a leaky bucket monitor/enforcer means that monitors the fast packet traffic and determines and marks a fast packet discard priority for each fast packet,

transit node means, operably coupled to the source edge node means, having a plurality of intermediate nodes for providing at said intermediate nodes fast packet transmission paths, and

destination edge node means, operably coupled to the transit node means, for providing at least a correlated congestion level and for outputting traffic at a realized throughput rate, such that where fast packets utilize unallocated or unused network capacity, the realized throughput rate of transmitted fast packets exceeds a negotiated throughput rate,

wherein the destination edge node means further includes a backwards correlated congestion level state determiner, i.e., BCCL STATE DET, operably coupled to provide a backwards correlated congestion level, i.e., BCCL, state to the leaky bucket monitor/enforcer means via a control fast packet further including a means for discarding fast packets that is operably coupled to monitor fast packet traffic in the source edge node means of the integrated fast packet network and for discarding fast packets when a BCCL state that indicates level of congestion is greater than a predetermined congestion value.

10. A system for providing rate-based congestion control of fast packet traffic A method for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least;

source edge node means, operably coupled to receive the fast packet traffic for transmission over the network, said source edge node means having a predetermined throughput rate, for rate-based monitoring and rate enforcement of the fast packet traffic utilizing a leaky bucket monitor/enforcer means that monitors the fast packet traffic and determines and marks a fast packet discard priority for each fast packet,

transit node means, operably coupled to the source edge node means, having a plurality of intermediate nodes for providing at said intermediate nodes fast packet transmission paths, and

destination edge node means, operably coupled to the transit node means, for providing at least a correlated congestion level and for outputting traffic at a realized throughput rate, such that where fast packets utilize unallocated or unused network capacity, the realized throughput rate of transmitted fast packets exceeds a negotiated throughput rate,

wherein the destination edge node means comprises at least;

a connection congestion level, i.e., CL, state determiner, operably coupled to the transit node means, for determining a connection congestion level state;

a fast packet adaption frame tag state determiner, operably coupled to the transit node means, for determining a fast packet adaption frame tag state;

a correlated congestion level, i.e, CL, determiner, operably coupled to the connection congestion level state determiner and to the fast packet adaption frame tag state determiner, for utilizing the congestion level state and the fast packet adaption frame tag state to determine a correlated congestion level that provides a backward correlated congestion level, i.e., BCCL, state to a backward correlated congestion level signal unit that is operably coupled to provide a backward correlated congestion level state indication to the source edge node means and that further provides a forward correlated congestion level, i.e., FCCL, to a forward correlated congestion level state determiner.

11. A system for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least:

source edge node means, operably coupled to receive the fast packet traffic for transmission over the network, said source edge node means having a predetermined throughput rate, for rate-based monitoring and rate enforcement of the fast packet traffic utilizing a leaky bucket monitor/enforcer means that monitors the fast packet traffic and determines and marks a fast packet discard priority for each fast packet,

transit node means, operably coupled to the source edge node means, having a plurality of intermediate nodes for providing at said intermediate nodes fast packet transmission paths, and

destination edge node means, operably coupled to the transit node means, for providing at least a correlated congestion level and for outputting traffic at a realized throughput rate, such that where fast packets utilize unallocated or unused network capacity, the realized throughput rate of transmitted fast packets exceeds a negotiated throughput rate,

wherein the destination edge node means comprises at least;

a connection congestion level, i.e., CL, state determiner, operably coupled to the transit node means, for determining a connection congestion level state;

a fast packet adaption, i.e., FPA, frame tag state determiner, operably coupled to the transit node means, for determining a fast packet adaption, i.e., FPA, frame tag state;

a correlated congestion level determiner, operably coupled to the connection congestion level state determiner and to the fast packet adaption frame tag state determiner, for utilizing the congestion level state and the fast packet adaption frame tag state to determine a correlated congestion level that provides a backward correlated congestion level state to a backward correlated congestion level signal unit that is operably coupled to provide a backward correlated congestion level state indication to the source edge node means and that further provides a forward correlated congestion level to a forward correlated congestion level state determiner,

wherein the forward correlated congestion level state determiner is further operably coupled to provide a frame relay forward explicit congestion notification to a frame relay forward explicit congestion notification marking unit that outputs frames of transmitted fast packets.

12. A system for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least:

source edge node means, operably coupled to receive the fast packet traffic for transmission over the network, said source edge node means having a negotiated throughput rate, i.e., R, and bucket size, i.e.. B, for rate-based monitoring and rate enforcement of the fast packet traffic utilizing a leaky bucket monitor/enforcer means for at least determining and marking a fast packet discard priority such that, when a frame is received in excess of said rate R and bucket size B, the discard priority of a first fast packet comprising said frame is set to `last discarded` and the discard priority of subsequent fast packets is set to `first discarded`, except that if the backwards correlated congestion level state detection unit indicates that congestion along the path exceeds a predetermined level, the frame is discarded and a control fast packet is sent, or if the negotiated excess rate, i.e., R2, and excess bucket size, i.e., B2, is exceeded, the frame is discarded,

transit node means, operably coupled to the source edge node means, having a plurality of intermediate nodes for providing at said intermediate nodes fast packet transmission paths utilizing congestion-reducing means for determining a transit node queue group, i.e.,TNQG, congestion level for fast packets and for discarding fast packets based on said transit node queue group congestion level and on a discard priority, and

destination edge node means, operably coupled to the transit node means, for providing at least a correlated congestion level and for outputting reassembled frames of transmitted fast packets at a realized throughput rate,

such that the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate where fast packets utilize unused or unallocated network capacity, wherein the destination edge node means further includes a backwards correlated congestion level state determiner, i.e., BCCL STATE DET, operably coupled to provide a backwards correlated congestion level, i.e., BCCL, state to the leaky bucket monitor/enforcer means via a control fast packet.

13. The system of claim 12, further including a low pass filter, operably coupled to the congestion-reducing means, for averaging a sampled queue depth that is input from a queue depth sampler.

14. A system for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least:

source edge node means, operably coupled to receive the fast packet traffic for transmission over the network, said source edge node means having a negotiated throughput rate, i.e., R, and bucket size, i.e., B, for rate-based monitoring and rate enforcement of the fast packet traffic utilizing a leaky bucket monitor/enforcer means for at least determining and marking a fast packet discard priority such that, when a frame is received in excess of said rate R and bucket size B, the discard priority of the first fast packet comprising said frame is set to `last discarded` and the discard priority of subsequent fast packets is set to `first discarded`, except that if the backwards correlated congestion level, i.e., BCCL, state detection unit indicates that congestion along the path exceeds a predetermined level, the frame is discarded and a control fast packet is sent, or if the negotiated excess rate, i.e., R2, and excess bucket size, i.e., B2, is exceeded, the frame is discarded,

transit node means, operably coupled to the source edge node means, having a plurality of intermediate nodes for providing at said intermediate nodes fast packet transmission paths utilizing congestion-reducing means for determining a transit node queue group congestion level, i.e., TNOG, for fast packets and for discarding fast packets based on said transit node queue group congestion level and on a discard priority, and

destination edge node means, operably coupled to the transit node means, for providing at least a correlated congestion level and for outputting by said destination edge node means, reassembled frames of transmitted fast packets at a realized throughput rate,

such that the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate where fast packets utilize unused or unallocated network capacity, further including a backwards correlated congestion level state determiner, i.e., BCCL STATE DET, operably coupled to the destination edge node means, for providing a backwards correlated congestion level state to the leaky bucket monitor/enforcer means via a control fast packet and further including a frame relay backwards explicit congestion notification, i.e., BECN, marking unit, operably coupled to the backwards correlated congestion level state determiner, i.e., BCCL STATE DET, for setting a backwards explicit congestion notification, BECN, bit when the backward correlated congestion level is equal to or greater than a predetermined congestion level.

15. A system for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least:

source edge node means, operably coupled to receive the fast packet traffic for transmission over the network, said source edge node means having a negotiated throughput rate, i.e., R, and bucket size, i.e., B, for rate-based monitoring and rate enforcement of the fast packet traffic utilizing a leaky bucket monitor/enforcer means for at least determining and marking a fast packet discard priority such that, when a frame is received in excess of said rate R and bucket size B, the discard priority of the first fast packet comprising said frame is set to `last discarded` and the discard priority of subsequent fast packets is set to `first discarded`, except that if the backwards correlated congestion level, i.e., BCCL, state detection unit indicates that congestion along the path exceeds a predetermined level, the frame is discarded and a control fast packet is sent, or if the negotiated excess rate, i.e., R2, and excess bucket size, i.e., B2, is exceeded, the frame is discarded,

transit node means, operably coupled to the source edge node means, having a plurality of intermediate nodes for providing at said intermediate nodes fast packet transmission paths utilizing congestion-reducing means for determining a transit node queue group, i.e., TNQG, congestion level for fast packets and for discarding fast packets based on said transit node queue group, TNQG, congestion level and on a discard priority, and

destination edge node means, operably coupled to the transit node means, for providing at least a correlated congestion level and for outputting by said destination edge means, reassembled frames of transmitted fast packets at a realized throughput rate,

such that the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate where fast packets utilize unused or unallocated network capacity,

wherein the destination edge node means comprises at least;

a connection congestion level, i.e., CL, state determiner, operably coupled to the transit node means, for determining a connection congestion level state;

a fast packet adaption, i.e., FPA, frame tag state determiner, operably coupled to the source edge node means, for determining a fast packet adaption frame tag state;

a correlated congestion level, i.e., CL, determiner, operably coupled to the connection congestion level state determiner and to the fast packet adaption frame tag state determiner, for utilizing the congestion level state and the fast packet adaption frame tag state to determine a correlated congestion level that provides a backward correlated congestion level, i.e., BCCL, state to a backward correlated congestion level, i.e., BCCL, signal unit that is operably coupled to provide a backward correlated congestion level state indication to the source edge node means and that further provides a forward correlated congestion level, i.e., FCCL, to a forward correlated congestion level state determiner.

18. The method of claim 15 wherein the congestion level field is two bits or an equivalent of two bits.

16. A system for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least:

source edge node means, operably coupled to receive the fast packet traffic for transmission over the network, said source edge node means having a negotiated throughput rate, i.e., R, and bucket size, i.e., B, for rate-based monitoring and rate enforcement of the fast packet traffic utilizing a leaky bucket monitor/enforcer means for at least determining and marking a fast packet discard priority such that, when a frame is received in excess of said rate R and bucket size B, the discard priority of the first fast packet comprising said frame is set to `last discarded` and the discard priority of subsequent fast packets is set to `first discarded`, except that if the backwards correlated congestion level, i.e.. BCCL state detection unit indicates that congestion along the path exceeds a predetermined level, the frame is discarded and a control fast packet is sent, or if the negotiated excess rate R2 and excess bucket size B2 is exceeded, the frame is discarded,

transit node means, operably coupled to the source edge node means, having a plurality of intermediate nodes for providing at said intermediate nodes fast packet transmission paths utilizing congestion-reducing means for determining a transit node queue group congestion level for fast packets and for discarding fast packets based on said transit node queue group congestion level and on a discard priority, and

destination edge node means, operably coupled to the transit node means, for providing at least a correlated congestion level and for outputting, by said destination edge node means, reassembled frames of transmitted fast packets at a realized throughput rate,

such that the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate where fast packets utilize unused or unallocated network capacity,

wherein the destination edge node means comprises at least;

a connection congestion level state determiner, operably coupled to the transit node means, for determining a connection congestion level state;

a fast packet adaption frame tag state determiner, operably coupled to the source edge node means, for determining a fast packet adaption frame tag state;

a correlated congestion level determiner, operably coupled to the connection congestion level state determiner and to the fast packet adaption frame tag state determiner, for utilizing the congestion level CL state and the fast packet adaption frame tag state to determine a correlated congestion level that provides a backward correlated congestion levelstate to a backward correlated congestion level signal unit that is operably coupled to provide a backward correlated congestion level, i.e., BCCL, state indication to the source edge node means and that further provides a forward correlated congestion level to a forward correlated congestion level state determiner,

wherein the forward correlated congestion level, i.e., FCCL, state determiner is further operably coupled to provide a frame relay forward explicit congestion notification, i.e., FECN, to a frame relay forward explicit congestion notification marking unit that outputs the reassembled frames of transmitted fast packets.

17. A method for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least the steps of:

rate-based monitoring and rate enforcing the fast packet traffic utilizing a leaky bucket monitor/enforcer,

providing, at a plurality of intermediate nodes, fast packet transmission paths, and

providing at least a correlated congestion level and for outputting, by a destination edge node unit, reassembled frames of transmitted fast packets at a realized throughput rate,

such that where fast packets utilize unused or unallocated network capacity the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate,

wherein utilizing the leaky bucket monitor/enforcer that provides a fast packet discard priority comprises at lest the steps of utilizing a leaky bucket monitor/enforcer for at least determining and marking a fast packet discard priority such that when a frame is received in excess of the negotiated rate R, the discard priority of the first fast packet comprising said frame is set to Last discard and the discard priority of subsequent fast packets is set to First discard,

wherein the leaky bucket and discard priority marking, upon receiving a fast packet, utilize one of the following sets of steps;

(A) determining whether the fast packet is a first packet in a frame;

where affirmative, updating the leaky bucket queue length Q and setting a first clock;

determining whether the discard eligibility (DE) bit is set in the frame relay frame;

where DE is unset, determining whether Q<

B;

where affirmative, updating leaky bucket 2 with queue length Q2 and setting a second clock;

determining whether Q2 is greater than a second preselected maximum allocation (bucket size) B2;

where Q2≦

B2, unsetting an excess indication;

determining a number of bits (K) in the fast packet and updating Q2 such that Q2=Q2+k;

setting frame mark indication;

determining whether a severe congestion level (greater than or equal to a predetermined congestion level) is set;

where severe congestion indication is unset, tagging (marking) an FPA frame state;

setting a discard priority to Last Discarded; and

transmitting the fast packet;

(B) where the fast packet is other than the first packet in the frame, determining whether excess indication is set, and where excess indication is set, and discarding the fast packet;

(C) where excess indication is unset, determining whether a frame mark indication is set;

where the frame mark indication is set, determining whether severe congestion indication is set;

where the severe congestion indication is set, and discarding the fast packet;

(D) where the frame mark indication is unset, determining the number of bits (K) in the packet;

updating Q such that Q=Q+K;

setting a discard priority to Last Discarded; and

transmitting the fast packet;

(E) where the severe congestion level indication is unset, determining the number of bits (K) in the packet;

updating Q2 such that Q2=Q2+K;

setting a discard priority to First Discarded; and

transmitting the fast packet;

(F) where Q≦

B, unsetting the frame mark indication;

determining the number of bits (K) in the packet;

updating Q such that Q=Q+K;

setting a discard priority to Last Discarded; and

transmitting the fast packet;

(G) where the DE bit is set (typically to

     1), bypassing the step of determining whether Q>

B in (25A) above, and otherwise proceeding as set forth in step (25A);

(H) where Q2>

B2, setting an excess indication; and

discarding the fast packet; and

(I) where a severe congestion level indication is set, discarding the fast packet;

creating an empty packet;

tagging (marking) an FPA frame state;

setting a discard priority to Last Discarded; and

transmitting the fast packet.

19. The method of claim 17, further including the step of providing a backwards correlated congestion level (BCCL) state to the leaky bucket monitor/enforcer.

20. The method of claim 19 further including the step of setting a backward explicit congestion notification (BECN) bit when the backward correlated congestion level is equal to or greater than a predetermined congestion level.

21. A method for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least the steps of:

rate-based monitoring and rate enforcing the fast packet traffic utilizing a monitor/enforcer,

providing, at a plurality of intermediate nodes, fast packet transmission paths, and

providing at least a correlated congestion level and for outputting, by a destination edge node unit, reassembled frames of transmitted fast packets at a realized throughput rate,

such that the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate where fast packets utilize unused or unallocated network capacity,

wherein the step of providing a plurality of intermediate nodes, fast packet transmission paths includes at least utilizing a congestion-reducing unit for determining a transit node queue group, i.e., TNQG, congestion level for fast packets and for discarding fast packets based on said TNQG congestion level and on a discard priority,

wherein steps for determining a transit node queue group congestion level includes sampling a transit queue group for congestion levels such that one of the following sets of steps is executed in accordance with determinations as set forth below;

(A) sampling a queue length from a transit queue;

updating an averaged queue length for the transit queue;

determining whether an average queue length is greater than a first predetermined threshold1 {see step set (29B)};

where affirmative, determining whether the average queue length is greater than a second predetermined threshold2 {see step set (29C)};

where affirmative, determining whether the average queue length is greater than a third predetermined threshold3 {see step set (29D)};

where affirmative, setting the congestion level for the queue to severe;

determining whether all queues in a selected group have been sampled {see step set (29E)}; and

, where affirmative, determining whether the queue group congestion level, CL, is greater than a predetermined maximum congestion level in the queue group {see step set (29F)};

(B) in step (29A) where the average queue length is less than or equal to the threshold1, setting the CL to normal and proceeding to the step of determining whether all queues in the selected group have been sampled in step (29A);

(C) in step (29A) where the average queue length is less than or equal to the threshold2, setting the CL to mild and proceeding to the step of determining whether all queues in the selected group have been sampled in step (29A);

(D) in step (29A) where the average queue length is less than or equal to the threshold3, setting the CL to moderate and proceeding to the step of determining whether all queues in the selected group have been sampled in step (29A);

(E) in step (29A) where at least one queue in the selected group is unsampled, proceeding to the step of reading a queue length from a transit queue in step (29A); and

(F) in step (29A), where the previous value of the queue group congestion level, CL, is less than the greatest congestion level of any queue in the queue group, or if the congestion levels of all queues in the queue group are `normal`, setting the queue group congestion level to the greatest congestion level of any queue in the queue group;

otherwise, the queue group CL is unchanged.

22. A method for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least the steps of:

rate-based monitoring and rate enforcing the fast packet traffic utilizing a leaky bucket monitor/enforcer that monitors the fast packet traffic and determines and marks a fast packet discard priority for each fast packet,

providing, at a plurality of intermediate nodes, fast packet transmission paths, and

providing at least a correlated congestion level and for outputting, by a destination edge node unit, reassembled frames of transmitted fast packets at a realized throughput rate,

such that the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate where fast packets utilize unused or unallocated network capacity,

wherein the step of providing at least a correlated congestion level and for outputting reassembled frames of transmitted fast packets at a realized throughput rate comprises at least the steps of;

determining a connection congestion level, CL, state;

determining a fast packet adaption, FPA, frame tag state;

utilizing the CL state and the FPA frame tag state to determine a correlated congestion level,

providing a backward correlated congestion level, BCCL, state to a BCCL signal unit, and

providing a forward correlated congestion level, FCCL, to a FCCL state determiner.

23. The method of claim 22 further including the step of providing a frame relay forward explicit congestion notification (FECN) to a frame relay FECN marking unit that outputs the reassembled frames of transmitted fast packets.

24. A method for providing rate-based congestion control of fast packet traffic having plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least the steps of:

rate-based monitoring and rate enforcing the fast packet traffic utilizing a leaky bucket monitor/enforcer,

providing, at a plurality of intermediate nodes, fast packet transmission paths, and

providing at least a correlated congestion level and for outputting, by a destination edge node unit, reassembled frames of transmitted fast packets at a realized throughput rate,

such that the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate where fast packets utilize unused or unallocated network capacity,

further including packet discarding and congestion level marking for data packets such that, for each data packet to be transmitted, one of the following sets of steps is followed at an intermediate node in accordance with determinations as set forth below;

(A) selecting a packet from a queue of data packets to be transmitted;

determining whether an instantaneous queue length is less than a predetermined high discard level {see step set (32B)};

where affirmative, determining whether the queue group congestion level, CL, is severe, or alternatively, whether the instantaneous queue length is greater than a predetermined low discard level {see step set (32C)};

where affirmative, determining whether the discard priority is Last Discarded {see step set (32D)};

where affirmative, determining whether the packet CL is less than the queue group CL {see step set (32E)};

where affirmative, setting the packet CL equal to the queue group CL; and

transmitting the packet;

(B) in step (32A) where the instantaneous queue length is greater than or equal to the predetermined high discard level, discarding the packet; and

proceeding to select another packet from a queue of data packets to be transmitted in step (32A);

(C) in step (32A) where the queue group congestion level, CL, is other than severe and the instantaneous queue length is less than or equal to a predetermined low discard level, proceeding to determining whether the packet CL is less than the queue group CL in step (32A);

(D) in step (32A) where the discard priority is other than the Last Discarded, discarding the packet; and

proceeding to select another packet from a queue of data packets to be transmitted in step (32A); and

(E) in step (32A) where the packet CL is greater than or equal to the queue group CL, transmitting the packet,

25. A method for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least the steps of:

rate-based monitoring and rate enforcing the fast packet traffic utilizing a leaky bucket monitor/enforcer that monitors the fast packet traffic and determines and marks a fast packet discard priority for each fast packet,

providing, at a plurality of intermediate nodes, fast packet transmission paths, and

providing at least a correlated congestion level and for outputting, by a destination edge node unit, reassembled frames of transmitted fast packets at a realized throughput rate,

such that where fast packets utilize unused or unallocated network capacity the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate,

further including packet discarding and congestion level marking at a voice transmit queue such that, for each voice packet to be transmitted, one of the following sets of steps is followed in accordance with determinations as set forth below;

(A) selecting a packet from a queue of voice packets to be transmitted;

setting variable PDP, packet discard priority, equal to a packet discard priority and variable IQL to an instantaneous queue length;

determining whether IQL is greater than a predetermined voice watermark3 {see step set (33B)};

where the IQL is less than or equal to the predetermined voice watermark3, determining whether IQL is greater than a predetermined voice watermark2 and PDP is unequal to Last Discard {see step set (33C)};

where IQL is less than or equal to the predetermined voice watermark2 or PDP is equal to Last Discarded, determining whether IQL is greater than a predetermined voice watermark1 and PDP equals a first discard setting {see step set (33D)};

where IQL is less than or equal to the predetermined voice watermark1 or PDP is unequal to First Discarded, determining whether the packet CL is less than the queue group CL {see step set (33E)};

where affirmative, setting the packet CL equal to the queue group CL; and

transmitting the packet;

(B) in step (33A) where the IQL is greater than the predetermined voice watermark3, discarding the packet; and

proceeding to selecting a packet from a queue of voice packets to be transmitted in step (33A);

(C) in step (33A) where the IQL is greater than the predetermined voice watermark2 and PDP is unequal to Last Discard, discarding the packet; and

proceeding to selecting a packet from a queue of voice packets to be transmitted in step (33A);

(D) in step (33A) where the IQL is greater than the predetermined voice watermark1 and PDP equals to the first discard, discarding the packet; and

proceeding to selecting a packet from a queue of voice packets to be transmitted in step (33A);

(E) in step (33A) where the packet CL is greater than or equal to the queue group CL, transmitting the packet.

26. A method for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least the steps of:

rate-based monitoring and rate enforcing the fast packet traffic utilizing a leaky bucket monitor/enforcer that monitors the fast packet traffic and determines and marks a fast packet discard priority for each fast packet,

providing, at a plurality of intermediate nodes, fast packet transmission paths, and

providing at least a correlated congestion level and for outputting, by a destination edge node unit, reassembled frames of transmitted fast packets at a realized throughput rate,

such where fast packets utilize unused or unallocated network capacity the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate,

wherein the step of providing at least a correlated congestion level and outputting reassembled frames of transmitted fast packets further includes steps for updating congestion and tagging status, forward explicit congestion notification, FECN, marking and creation of backward control packet at a destination edge node such that, for each received outbound packet, one of the following sets of steps is followed in accordance with determinations as set forth below;

(A) updating the congestion status of the received outbound packet;

determining whether the packet is a first packet in the frame {see step set (34B)};

where affirmative, updating a fast packet adaption tagging status, state;

determining whether the forward path is congested and tagged, or alternatively, severely congested {see step set (34C)};

where the forward path is other than congested or the packet is untagged, and the forward path is other than severely congested, determining whether the tagging or congestion status has changed {see step set (34D)};

where the tagging or congestion status has changed, creating and storing a backward congestion code;

storing a current tag and congestion status;

setting a counter1 to a predetermined number N1;

creating a control packet for a backward direction; and

setting a control field for a backward congestion code and setting the control packet discard priority to Last Discard;

(B) in step (34A) where the outbound packet is other than a first packet in the frame, proceeding to the step of determining whether the tagging or congestion status has changed in step (34A);

(C) in step (34A) where the forward path is congested and the packet is tagged, or alternatively, the forward path is severely congested, setting a FECN bit in the frame relay frame;

(D) in step (34C) where tagging and congestion status are unchanged, determining whether the packet is the first packet in the frame {see step set (34E)};

where the packet is the first packet in the frame, determining whether a counter1 is set to zero;

where the counter1 is set to zero, proceeding to the step of setting counter1 to the predetermined number N1 of step (34A);

(E) in step (34D) where the packet is other than the first packet in the frame, ending the status determining steps; and

(F) in step (34D) where the counter1 is set to other than zero, setting the counter1 to counter1-1.

27. A method for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least the steps of:

rate-based monitoring and rate enforcing the fast packet traffic utilizing a leaky bucket monitor/enforcer that monitors the fast packet traffic and determines and marks a fast packet discard priority for each fast packet,

providing, at a plurality of intermediate nodes, fast packet transmission paths, and

providing at least a correlated congestion level and for outputting, by a destination edge node unit, reassembled frames of transmitted fast packets at a realized throughput rate,

such that where fast packets utilize unused or unallocated network capacity the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate,

wherein the step of providing at least a correlated congestion level and outputting reassembled frames of transmitted fast packets further includes steps for updating a tag status when receiving a first packet in a frame at a destination edge node such that, for each first packet in a frame received, one of the following sets of steps is followed in accordance with determinations as set forth below;

(A) determining whether the fast packet adaption, FPA, state is marked , i.e., tagged, {see step set (35B)};

where the FPA is untagged, determining whether a counter2 is set to zero {see step set(35C)};

where affirmative, setting a current tag status equal to untagged;

(B) where the FPA is tagged, setting the counter2 equal to a predetermined second number N2; and

(C) where the counter2 is greater than zero, decrementing counter2, setting the current tag status equal to tagged.

28. A method for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least the steps of:

rate-based monitoring and rate enforcing the fast packet traffic utilizing a leaky bucket monitor/enforcer that monitors the fast packet traffic and determines and marks a fast packet discard priority for each fast packet,

providing, at a plurality of intermediate nodes, fast packet transmission paths, and

providing at least a correlated congestion level and for outputting, by a destination edge node unit, reassembled frames of transmitted fast packets at a realized throughput rate,

such that where fast packets utilize unused or unallocated network capacity the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate,

where the step of providing at least a correlated congestion level and outputting reassembled frames of transmitted fast packets further includes steps for creating and storing a backward congestion code at a destination edge node such that, for each packet having a tag or congestion status changed, one of the following sets of steps is followed in accordance with determinations as set forth below;

(A) determining whether a congestion level, CL, is one of;

normal and mild {see step set (36B)}, where CL is other than one of normal and mild, determining whether CL is moderate {see step set (36C)};

where CL is other than one of normal, mild, and moderate, determining whether the tag status , i.e., state, is tagged {see step set (36D)};

where the tag status is tagged, setting a backward congestion code equal to severe;

storing the backward congestion code;

(B) in step (36A) where the congestion level is equal to one of normal and mild, setting the backward congestion code equal to normal and storing the backward congestion code;

(C) in step (36A) where the congestion level is equal to moderate, determining whether the tag status is tagged {see step set (36E)};

where the tag status is tagged, setting the backward congestion code equal to moderate; and

storing the backward congestion code;

(D) in step (36A) where the tagged status is untagged, setting the backward congestion code equal to moderate; and

storing the backward congestion code;

(E) in step (36C) where the tag status is untagged, setting the backward congestion code equal to normal; and

storing the backward congestion code.

29. A method for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least the steps of:

rate-based monitoring and rate enforcing the fast packet traffic utilizing a leaky bucket monitor/enforcer that monitors the fast packet traffic and determines and marks a fast packet discard priority for each fast packet,

providing, at a plurality of intermediate nodes, fast packet transmission paths, and

providing at least a correlated congestion level and for outputting, by a destination edge node unit, reassembled frames of transmitted fast packets at a realized throughput rate,

such that where fast packets utilize unused or unallocated network capacity the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate,

wherein the rate monitoring/enforcing of traffic utilizing a monitor/enforcer further includes steps for receiving a control packet in a backward direction at a source edge node such that for each control packet received, one of the following sets of steps is followed in accordance with determinations as set forth below;

(A) sampling a control field of the received control packet;

determining whether the control field has changed from a previous backward congestion indication {see step set (37B)};

where affirmative, determining whether the control field is a normal value {see step set (37C)};

where the control field is other than normal, determining whether the control field is a moderate value {see step set (37D)};

where the control field is moderate, setting the control field to a moderate indication;

(B) in step (37A) where the backward congestion indication, i.e., value, is unchanged, ceasing taking further steps to set the control field;

(C) in step (37A) where the control field is a normal value, setting the backward congestion indication to a normal indication; and

(D) in step (37A) where the control field is other than a normal value and other than a moderate value, setting the control field to a severe indication.

30. A method for providing rate-based congestion control of fast packet traffic having a plurality of fast packets in an integrated fast packet network, each packet being capable of conveying a plurality of levels of congestion indication, comprising at least the steps of:

rate-based monitoring and rate enforcing the fast packet traffic utilizing a leaky bucket monitor/enforcer that monitors the fast packet traffic and determines and marks a fast packet discard priority for each fast packet,

providing, at a plurality of intermediate nodes, fast packet transmission paths, and

providing at least a correlated congestion level and for outputting, by a destination edge node unit, reassembled frames of transmitted fast packets at a realized throughput rate,

such that where fast packets utilize unused or unallocated network capacity the realized throughput rate of transmitted fast packets exceeds a predetermined throughput rate,

wherein the rate monitoring/enforcing of traffic utilizing a monitor/enforcer further includes steps for receiving a data fast packet in a backward direction and setting a backward explicit congestion notification, i.e., BECN, at a source edge node such that, for each control packet received in a backward direction, one of the following sets of steps is followed in accordance with determinations as set forth below;

(A) determining whether the packet is a first fast packet in its frame {see step set (38B)};

where the fast packet is a first fast packet in its frame, determining whether a backward congestion indication is equal to normal {see step set (38C)};

where backward congestion indication is equal to normal, ceasing taking steps to set BECN;

(B) in step (38A) where the fast packet is other than a first fast packet in its frame, ceasing taking further steps to set the BECN; and

(C) in step (38A) where the backward congestion indication is indicated as other than normal, setting the frame relay BECN to a set state.