Endpoint registration with local back-off in a call processing system

• US 20050068907A1
• Filed: 09/14/2004
• Published: 03/31/2005
• Est. Priority Date: 09/30/2003
• Status: Active Grant

• Current Assignee: Arlington Technologies, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Avaya Incorporated
• Inventors: Kintala, Chandra M.R., Garg, Sachin, Stott, David Thomas, Naybor, Edward Vincent
• Granted Patent: US 8,050,199 B2
• Time in Patent Office: Days
• US Class Current: 370/270
• CPC Class Codes: H04L 65/1073 Registration or de-registration
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1019 Random or heuristic server selection
• CPC Class Codes: H04L 67/1034 Reaction to server failures by a load balancer
• 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
• CPC Class Codes: H04M 3/12 Marking faulty circuits "busy"; Enabling equipment to disengage itself from faulty circuits ; Using redundant circuits; Response of a circuit, apparatus or system to an error
• CPC Class Codes: H04M 3/5234 Uniform load distribution
• CPC Class Codes: H04M 3/5237 Interconnection arrangements between ACD systems

Abstract

A call processing system, which may include multiple distributed call center sites, utilizes a local back-off approach to endpoint registration. The call processing system comprises a plurality of endpoints and at least a first server, wherein the endpoints register with the first server in order to send and receive calls in the call processing system. Responsive to an end-to-end connectivity failure or other designated event, a registration process is initiated in the call processing system for a given one of the endpoints. The issuance of at least one message of the sequence for the given endpoint is controlled so as to provide a local random back-off or other local back-off of the controlled message at that endpoint. For example, a second server implemented as an aggregation server may be operative to control the issuance of messages by the endpoints so as to provide a local random back-off for each of the plurality of endpoints by staggering the delivery of failure notifications to the endpoints.

Claims

1. A method for use in a call processing system comprising a plurality of endpoints and at least a first server, wherein the endpoints register with the first server in order to send and receive calls in the call processing system, the method comprising the steps of:

responsive to a designated event, initiating in the call processing system a registration sequence for a given one of the endpoints; and

controlling the issuance of at least one message of the sequence for the given endpoint so as to provide a local back-off of the controlled message at that endpoint.

2. The method of claim 1 wherein the designated event comprises detection of a failure of end-to-end connectivity for the given endpoint.

3. The method of claim 1 wherein one or more of the endpoints comprise Internet Protocol (IP) endpoints.

4. The method of claim 1 wherein the given endpoint registers with the first server by exchanging a User Datagram Protocol (UDP) message sequence with the first server.

5. The method of claim 1 wherein the given endpoint registers with the first server by sending a GRQ message, receiving a GCF message, sending a RRQ message, and receiving a RCF message.

6. The method of claim 1 wherein the call processing system further comprises a router coupled between the endpoints and the first server, the router being operative to limit a rate at which specified messages are delivered from the endpoints to the first server.

7. The method of claim 6 wherein the specified messages comprise GRQ messages.

8. The method of claim 1 wherein the first server, if it is unable to process a specified message of the sequence for the given endpoint because it is already handling a registration process for a maximum number of the endpoints, is operative to send to the given endpoint a message indicating that another registration is in progress and requesting that the given endpoint retry its registration attempt after a designated interval.

9. The method of claim 1 wherein the local back-off for the given endpoint is provided subsequent to a detected failure of end-to-end connectivity for that endpoint and prior to transmission of an initial message of the message sequence from the given endpoint to the first server.

10. The method of claim 9 wherein the initial message comprises a GRQ message.

11. The method of claim 1 wherein one or more of the endpoints are provided with an indication of a particular back-off duration, the local back-off for the given endpoint being determined by that endpoint as a function of the back-off duration.

12. The method of claim 11 wherein the given endpoint determines the local back-off as a random local back-off by randomly selecting a back-off between zero and the particular back-off duration.

13. The method of claim 11 wherein the back-off duration is communicated to the given endpoint device by the first server.

14. The method of claim 1 wherein the controlling step is implemented in a second server coupled between the endpoints and the first server.

15. The method of claim 14 wherein the second server comprises an aggregation server operative to control the issuance of messages by the plurality of endpoints so as to provide a local back-off for each of the plurality of endpoints by staggering the delivery of failure notifications to the endpoints.

16. The method of claim 14 wherein the second server is configured to serve as a registration proxy for each of at least a subset of the plurality of endpoints.

17. The method of claim 16 wherein an IP address of the aggregation server is set to a first address in a list of server addresses.

18. The method of claim 14 wherein at least one of the first server and the second server is implemented at least in part within a communication switch of the call processing system.

19. The method of claim 14 wherein at least one of the first server and the second server is implemented at least in part externally to a communication switch of the call processing system.

20. An apparatus for use in a call processing system comprising a plurality of endpoints and at least a first server, wherein the endpoints register with the first server in order to send and receive calls in the call processing system, the apparatus comprising:

means for initiating in the call processing system, responsive to a designated event, a registration sequence for a given one of the endpoints; and

means for controlling the issuance of at least one message of the sequence for the given endpoint so as to provide a local back-off of the controlled message at that endpoint.