IP Phones Do Not Work After the eSpace U1930 Restarts

Symptom

After some  configurations are modified on the eSpace U1930 (serving as a SIP server), the  eSpace U1930 must be restarted. During the eSpace U1930 restart, all IP phones  register with the SIP server using the session boarder controller (SBC). After  the eSpace U1930 restart, the IP phones do not work. They can be used only after  being powered-cycled.

Possible Cause

The default interval for  the IP phone to update its registration with the SIP server is 3600s, which is  relatively long. After the eSpace U1930 is restarted, this interval has not  expired. The IP phones are still registered with the SIP server with the old  configurations.

Solution

Change the interval for  the IP phone to update its registration with the SIP server to 120s.