MGCP fallback mechanism enhancement

• US 20070073891A1
• Filed: 09/29/2005
• Published: 03/29/2007
• Est. Priority Date: 09/29/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Andreasen, Flemming, Urquizo, Alex, Foltan, Andrew
• Granted Patent: US 7,907,514 B2
• Time in Patent Office: Days
• US Class Current: 709/230
• CPC Class Codes: H04L 65/1043 Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/1106 Call signalling protocols; H.323 and related
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04M 7/1255 where the switching fabric and the switching logic are decomposed such as in Media Gateway Control

Abstract

A mechanism provides for communication of “keep-alive” messages from clients to servers in a packet telephony network environment. The servers may be call agents and the clients may be gateways or MGCP-controlled IP phones. A client (e.g., gateway) registers a virtual endpoint. Upon a period of inactivity in which the client does not receive any commands or acknowledgments from an assigned server (e.g., call agent), the client starts to send keep-alive messages periodically to the server. The keep-alive message may include an endpoint identifier that identifies the registered virtual endpoint. If the server fails to respond to the keep-alive messages after a period of time, the client initiates a fallback mechanism from a first call control protocol (e.g., MGCP) to a second call control protocol (e.g., H.323 or SIP), to provide call control handling using a default application. The keep-alive messages may be sent to other servers among the plural servers that are configured to operate with the client before determining whether to initiate the fallback mechanism. During the fallback state, the keep-alive message may be sent periodically until a response is received from the server. Communications with the assigned server may be reestablished thereupon based on the first call control protocol.

Claims

1. A method of communication by a client over a network having plural servers, one of the servers assigned to the client, the method comprising:

registering a virtual endpoint with the assigned server;

upon inactivity with the assigned server, sending a keep-alive message to the server, the keep-alive message including an endpoint identifier that identifies the registered virtual endpoint; and

upon failure to receive a response to the keep-alive message from the assigned server, initiating a fallback mechanism from a first call control protocol to a second call control protocol.

2. The method of claim 1 wherein the keep-alive message is according to an MGCP MESG format.

3. The method of claim 1 wherein the first call control protocol is MGCP and the second call control protocol is H.323.

4. The method of claim 1 wherein the first call control protocol is MGCP and the second call control protocol is Session Initiation Protocol.

5. The method of claim 1 further comprising sending keep-alive messages to other servers among the plural servers that are configured to operate with the client before determining whether to initiate the fallback mechanism.

6. The method of claim 1 wherein sending includes sending the keep-alive message periodically until a response is received from the server.

7. The method of claim 6 further including reestablishing communications with the assigned server based on the first call control protocol.

8. The method of claim 1 wherein the client is a gateway or media termination adapter and the servers are call agents in a VoIP network.

9. A method of communication by a gateway over a VoIP network having plural call agents, one of the call agents assigned to the gateway, the method comprising:

establishing communications with the assigned call agent based on Media Gateway Control Protocol (MGCP);

registering a virtual endpoint with the assigned call agent;

upon a period of inactivity with the assigned call agent, sending a an MGCP MESG message to the call agent, the MGCP MESG message including an endpoint identifier that identifies the registered virtual endpoint; and

upon failure to receive a response to the keep-alive message from the assigned call agent, initiating a fallback mechanism from MGCP to a second call control protocol.

10. The method of claim 9 wherein the second call control protocol is H.323.

11. The method of claim 9 wherein the second call control protocol is Session Initiation Protocol.

12. The method of claim 9 further comprising sending MGCP MESG messages to other call agents among the plural call agents that are configured to operate with the gateway before determining whether to initiate the fallback mechanism.

13. The method of claim 9 wherein sending includes sending the MGCP MESG message periodically until a response is received from the call agent.

14. The method of claim 13 further including reestablishing communications with the assigned call agent based on MGCP.

15. Apparatus for communication over a network having plural servers including an assigned server, the apparatus comprising:

means for registering a virtual endpoint with the assigned server;

means for sending a keep-alive message to the assigned server upon inactivity with the assigned server, the keep-alive message including an endpoint identifier that identifies the registered virtual endpoint; and

means for initiating a fallback mechanism from a first call control protocol to a second call control protocol upon failure to receive a response to the keep-alive message from the assigned server.

16. A client for communicating over a network having plural servers, one of the servers assigned to the client, the client comprising:

a virtual endpoint registration routine for registering a virtual endpoint with the assigned server;

a keep-alive messaging routine for sending a keep-alive message to the server upon inactivity with the assigned server, the keep-alive message including an endpoint identifier that identifies the registered virtual endpoint; and

a fallback routine for initiating a fallback mechanism from a first call control protocol to a second call control protocol upon failure to receive a response to the keep-alive message from the assigned server.

17. The client of claim 16 wherein the keep-alive message is according to an MGCP MESG format.

18. The client of claim 16 wherein the first call control protocol is MGCP and the second call control protocol is H.323 or Session Initiation Protocol.

19. The client of claim 16 wherein the keep-alive messaging routine sends keep-alive messages to other servers among the plural servers that are configured to operate with the client before the fallback routine initiates the fallback mechanism.

20. The client of claim 16 wherein the client is a gateway or media termination adapter and the servers are call agents in a VoIP network.