In the Cisco CallManager 4.x server, the Cisco IP phones at a remote site experiences registration problems

[TCC_2]

Core Issue

The IP phones on a remote site keep loosing connectivity with the Cisco CallManager and after the connectivity is lost the phones try to reregister.

Resolution

To resolve this issue, it is recommended that you increase the keepalives on the Cisco CallManager. The Cisco CallManager sends keepalive acknowledge messages to the registered devices once every 30 seconds. If 60 seconds go by without the receipt of a keepalive from a device, the Cisco CallManager closes the connection and the respective device tries to connect to the next Cisco CallManager server indicated in the Cisco CallManager group. If 90 seconds go by without the receipt of a keepalive acknowledge from the Cisco CallManager, the respective device tries to connect to the next Cisco CallManager server indicated in the Cisco CallManager group.

Complete these steps in order to increase the keepalives:

1. Choose Service > Service Parameters > Select CallManager and Service CallManager.
   
   
2. Under Cluster Wide Parameters, change the keepalive setting for the parameter Station Keep Alive Interval. By default it is set to 30 seconds.