Patent ID: 8223926
Filing Date: 2012-07-17
Classification: H04L,H04M

Abstract:
1. A method for registering with a call manager, comprising: maintaining a plurality of call managers associated with a plurality of levels; maintaining a connection between a first endpoint and each of a first call manager and a second call manager; registering the endpoint with the first call manager; sending keep-alive signals from the endpoint to the first call manager; sending keep-alive signals from the endpoint to the second call manager while registered with the first call manager; when a failure is detected in the first call manager, registering the endpoint with the second call manager; and when a failure is detected in the second call manager, registering the endpoint with a third call manager; while registered with the third call manager, sending keep-alive signals from the endpoint to the first call manager and the second call manager to monitor the operability of the first call manager and the second call manager; initiating a fall back process to fall back to any call manager that becomes operational after failing and is at a higher level than the third call manager; and un-registering from the third call manager and re-registering the endpoint with the second call manager when the second call manager regains operability since the second call manager is at a higher level than the third call manager.