Network load balancing and overload control

• US 9,847,942 B2
• Filed: 11/12/2015
• Issued: 12/19/2017
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Inventors: Hilt, Volker, Widjaja, Indra
• Primary Examiner(s): Vostal, O. C.
• Application Number:
  US14/939,587
• Publication Number:
  US 20160065475A1
• Time in Patent Office: 768 Days
• Field of Search: 709235
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/11 Identifying congestion
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 47/122 by diverting traffic away from congested entities
• CPC Class Codes: H04L 47/263 Rate modification at the source after receiving feedback
• CPC Class Codes: H04L 65/1016 IP multimedia subsystem [IMS]
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/101 based on network conditions
• CPC Class Codes: H04L 67/1023 based on a hash applied to IP addresses or costs
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

Load balancing and overload control techniques are disclosed for use in a SIP-based network or other type of network comprising a plurality of servers. In a load balancing technique, a first server receives feedback information from at least first and second downstream servers associated with respective first and second paths between the first server and a target server, the feedback information comprising congestion measures for the respective downstream servers. The first server dynamically adjusts a message routing process based on the received feedback information to compensate for imbalance among the congestion measures of the downstream servers. In an overload control technique, the first server utilizes feedback information received from at least one downstream server to generate a blocking message for delivery to a user agent.

Claims

1. An apparatus for facilitating overload control in a Session Initiation Protocol (SIP)-based network including an overloaded SIP server, the apparatus comprising:

a first SIP server of the network configured to receive SIP response messages from at least one downstream SIP server of the network, the downstream SIP server being associated with a path between the first SIP server and a target SIP server, the downstream SIP server being the overloaded SIP server and a nearest neighboring SIP server of the first SIP server, one or more of the SIP response messages including feedback information which comprises a utilization measure of the downstream SIP server;

wherein the first SIP server is further configured to generate a blocking message for delivery to a user agent associated with the network based on the feedback information, the blocking message comprising a SIP server internal error response message used to control overload of the overloaded SIP server; and

wherein a message routing process is adjusted responsive to the blocking message to route at least one new call over another path between the first SIP server and the target SIP server that does not include the downstream SIP server.

2. The apparatus of claim 1 wherein the SIP response messages comprise at least one SIP 500 response message and wherein the blocking message is generated based at least in part on the SIP 500 response message.

3. The apparatus of claim 1 wherein the SIP response messages comprise at least one SIP 100 response message and wherein the blocking message is generated based at least in part on the SIP 100 response message.

4. The apparatus of claim 3 wherein the blocking message is generated based at least in part on an overload status value in a header of the SIP 100 response message.

5. The apparatus of claim 1 wherein the SIP response messages are received in response to at least one SIP INVITE request sent from the first SIP server.

6. The apparatus of claim 1 wherein the downstream SIP server comprises the target SIP server.

7. The apparatus of claim 1 wherein the downstream SIP server comprises an egress server of the network.

8. The apparatus of claim 1 wherein the downstream SIP server comprises a core server of the network.

9. The apparatus of claim 1 wherein the first SIP server comprises an ingress server for the user agent.

10. The apparatus of claim 1 wherein the first SIP server comprises a downstream SIP server relative to an ingress SIP server for the user agent.

11. The apparatus of claim 1 wherein a message routing process is adjusted responsive to the blocking message to reject at least one new call that would otherwise utilize the path between the first SIP server and the target SIP server that includes the downstream SIP server.

12. The apparatus of claim 1 wherein the blocking message comprises a SIP 500 Server Internal Error response message.

13. An apparatus for facilitating overload control in a Session Initiation Protocol (SIP)-based network including an overloaded SIP server, the apparatus comprising:

a first SIP server of the network configured to receive SIP response messages from at least one downstream SIP server of the network, the downstream SIP server being associated with a path between the first SIP server and a target SIP server, the downstream SIP server being the overloaded SIP server and a nearest neighboring SIP server of the first SIP server, one or more of the SIP response messages including feedback information which comprises a utilization measure of the downstream SIP server;

wherein the first SIP server is further configured to generate a blocking message for delivery to a user agent associated with the network based on the feedback information, the blocking message comprising a SIP server internal error response message used to control overload of the overloaded SIP server; and

wherein the feedback information comprises a highest utilization measure of among utilization measures of a plurality of downstream SIP servers in the path between the first SIP server and the target SIP server.

14. A method for facilitating overload control in a Session Initiation Protocol (SIP)-based network including an overloaded SIP server, the method comprising:

receiving, by a first SIP server of the network, SIP response messages from at least one downstream SIP server of the network, the downstream SIP server being associated with a path between the first SIP server and a target SIP server, the downstream SIP server being the overloaded SIP server and a nearest neighboring SIP server of the first SIP server, one or more of the SIP response messages including feedback information which comprises a utilization measure of the downstream SIP server; and

generating, by the first SIP server, a blocking message for delivery to a user agent associated with the network based on the feedback information, the blocking message comprising a SIP server internal error response message used to control overload of the overloaded SIP server;

wherein a message routing process is adjusted responsive to the blocking message to route at least one new call over another path between the first SIP server and the target SIP server that does not include the downstream SIP server.

15. The method of claim 14 wherein a message routing process is adjusted responsive to the blocking message to reject at least one new call that would otherwise utilize the path between the first SIP server and the target SIP server that includes the downstream SIP server.

16. The method of claim 14 wherein:

the SIP response messages comprise at least one SIP 100 response message;

the blocking message is generated based at least in part on the SIP 100 response message; and

the blocking message is generated based at least in part on an overload status value in a header of the SIP 100 response message.

17. The method of claim 14 wherein the feedback information comprises a highest utilization measure of among utilization measures of a plurality of downstream SIP servers in the path between the first SIP server and the target SIP server.

18. An apparatus for facilitating overload control in a Session Initiation Protocol (SIP)-based network including an overloaded SIP server, the apparatus comprising:

a downstream SIP server of the network configured to send SIP response messages to a first SIP server of the network, the downstream SIP server being associated with a path between the first SIP server and a target SIP server, the downstream SIP server being the overloaded SIP server and a nearest neighboring SIP server of the first SIP server, one or more of the SIP response messages including feedback information which comprises a utilization measure of the downstream SIP server;

wherein the feedback information is utilized to generate a blocking message for delivery to a user agent associated with the network, the blocking message comprising a SIP server internal error response message used to control overload of the overloaded SIP server; and

wherein a message routing process is adjusted responsive to the blocking message to route at least one new call over another path between the first SIP server and the target SIP server that does not include the downstream SIP server.

19. The apparatus of claim 18 wherein:

the SIP response messages comprise at least one SIP 100 response message;

the blocking message is generated based at least in part on the SIP 100 response message; and

the blocking message is generated based at least in part on an overload status value in a header of the SIP 100 response message.

20. The apparatus of claim 18 wherein the feedback information comprises a highest utilization measure of among utilization measures of a plurality of downstream SIP servers in the path between the first SIP server and the target SIP server.