Congestion control in connection-oriented packet-switching networks

• US 20050157641A1
• Filed: 01/21/2004
• Published: 07/21/2005
• Est. Priority Date: 01/21/2004
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Inventors: Roy, Anindya
• Granted Patent: US 7,706,353 B2
• Time in Patent Office: Days
• US Class Current: 370/218
• CPC Class Codes: H04L 41/0896 Bandwidth or capacity management, i.e. automatically increasing or decreasing capacities flow or congestion control using dynamic resource allocation, e.g. in-call renegotiation, H04L47/76
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/122 by diverting traffic away from congested entities
• CPC Class Codes: H04L 47/26 using explicit feedback to the source, e.g. choke packets

Abstract

Congestion control in connection-oriented packet-switching networks is accomplished by rerouting any misbehaving non-real-time connection over an alternative path, if network resources permit. In one exemplary methodological implementation, a congestion notification is received by a node in a network indicating that there is traffic congestion in a path connecting the node to a destination node. The node ascertains whether an alternative path exists with better throughput for rerouting traffic between it and the destination node. The node selects the alternative path to route traffic between it and the destination node, if such an alternative path exists.

Claims

1. A method for performing congestion control in a connection-oriented packet-switching network, the method comprising:

receiving notification of traffic congestion in a first path connecting a source node and a destination node;

ascertaining whether an alternative path exists with better throughput for routing traffic than the first path; and

selecting the alternative path to route traffic between the source node and the destination node, if the alternative paths exists.

2. The method as recited in claim 1, wherein the first path is a non-real time virtual circuit connection between the source node and the destination node.

3. The method as recited in claim 1, wherein the alternative path is a non-real time virtual circuit connection between the source node and the destination node.

4. The method as recited in claim 1, wherein the traffic congestion is experienced at one or more nodes forming a portion of the first path connecting the source node and the destination node.

5. The method as recited in claim 1, wherein ascertaining whether the alternative path exists with better throughput for routing traffic than the first path, comprises determining whether an alternative path exists with an available cell rate that is greater than a available cell rate for the first path, the available cell rate for the first path measured when the traffic congestion in the first path is eliminated through cell rate control.

6. A method for performing congestion control in a node in a connection-oriented packet-switching network, the method comprising:

receiving notification of traffic congestion at a node located in a first path connecting a source node and a destination node, wherein the first path is a non-real time connection with a Minimum Cell Rate (MCR) of R_ACR and a Peak Cell Rate (PCR) of R_PCR;

ascertaining whether M alternative paths exist with available resources able to satisfy the R_ACR for transferring traffic between the source node and the destination node, wherein M is equal to or greater than 1; and

selecting one of the M alternative paths to reroute the traffic between the source node and the destination node the if the M alternative paths exist.

7. The method as recited in claim 6, wherein selecting one of the M alternative paths to reroute the traffic, comprises selecting one of the M alternative paths which best satisfies the R_ACR in accordance with one or more rules, if there are more than one of the M alternative paths.

8. The method as recited in claim 6, wherein selecting one of the M alternative paths to reroute the traffic, comprises selecting one of the M alternative paths with a maximum amount unreserved resources to satisfy the R_ACR, if there is more than one of the M alternative paths.

9. The method as recited in claim 6, wherein selecting one of the M alternative paths to reroute the traffic, comprises selecting one of the M alternative paths with a least amount unreserved resources but enough unreserved resources to support the R_ACR, if there is more than one of the M alternative paths.

10. The method as recited in claim 6, wherein selecting one of the M alternative paths to reroute the traffic, comprises selecting a first one of the M alternative paths found to satisfy the R_ACR, if there is more than one of the M alternative paths.

11. The method as recited in claim 6, wherein selecting one of the M alternative paths to reroute the traffic, comprises selecting one of the M alternative paths that satisfies the R_ACR according to one or more custom criteria, if there is more than one of the M alternative paths.

12. The method as recited in claim 6, wherein selecting one of the M alternative paths to reroute the traffic, comprises selecting one of the M alternative paths that satisfies the R_ACR according to one or more fuzzy rules, if there is more than one of the M alternative paths.

13. One or more computer-readable media having stored thereon computer executable instructions that, when executed by one or more processors, causes a computer to:

receive notification of traffic congestion in a first path connecting a source node and a destination node in a connection-oriented packet-switching network;

ascertain whether an alternative path exists with better throughput for routing traffic than the first path; and

select the alternative path to route traffic, if the alternative paths exists.

14. One or more computer-readable media as recited in claim 13, wherein the computer is a switch.

15. One or more computer-readable media having stored thereon computer executable instructions that, when executed by one or more processors, causes a computer to:

receive notification of traffic congestion at a node located in a first path connecting a source node and a destination node, wherein the first path is a non-real time connection with a Minimum Cell Rate (R_MCR) and Peak Cell Rate (PCR) of R_PCR;

ascertain whether M alternative paths exist with available resources able to satisfy the R_PCR for transferring traffic between the source node and the destination node, wherein M is equal to or greater than 1; and

select one of the M alternative paths to reroute the traffic between the source node and the destination node the if the M alternative paths exist.

16. A method for performing congestion control in a node in a connection-oriented packet-switching network, the method comprising:

receiving notification of traffic congestion at a node located in a first path connecting a source node and a destination node, wherein the first path is a non-real time connection with a Minimum Cell Rate (R_MCR) and Peak Cell Rate (PCR) of R_PCR;

ascertaining whether M alternative paths exist with available resources able to satisfy the R_ACR for transferring traffic between the source node and the destination node, wherein M is equal to or greater than 1;

selecting one of the M alternative paths to reroute the traffic between the source node and the destination node the if the M alternative paths exist;

ascertaining whether X alternative paths exist with available resources able to satisfy a reduced Available Cell Rate (ACR) of R′

_ACR, if M alternative paths do not exist, wherein R′

_ACR is less than the R_ACR, but is greater than a new ACR for the first path if rate control is instituted to eliminate the traffic congestion; and

selecting one of the X alternative paths to reroute the traffic between the source node and the destination node the if the X alternative paths exist.

17. A system, comprising:

means for receiving notification of traffic congestion at a node located in a first path connecting a source node and a destination node, wherein the first path is a non-real time connection with a Minimum Cell Rate (R_MCR) and Peak Cell Rate (PCR) of R_PCR;

means for ascertaining whether M alternative paths exist with available resources able to satisfy the R_ACR for transferring traffic between the source node and the destination node, wherein M is equal to or greater than 1; and

means for selecting one of the M alternative paths to reroute the traffic between the source node and the destination node the if the M alternative paths exist.

18. The system as recited in claim 17, further comprising means for ascertaining whether X alternative paths exist with available resources able to satisfy a reduced Available Cell Rate (ACR) of R′

_ACR, if M alternative paths do not exist, wherein R′

_ACR is less than the R_ACR, but is greater than a new ACR for the first path if rate control is instituted to eliminate the traffic congestion; and

means for selecting one of the X alternative paths to reroute the traffic between the source node and the destination node the if the X alternative paths exist.