2 CUCM cluster, both CUCMs are in the HQ. A remote site is provisioned with SRST. If WAN is down, how long does it take for phone realize it loses the connection with CUCM. I thought it should try 90s with primary, then try 180s with 2nd server, then try SRST router. But we noticed phone started registering with SRST in about 10s when wan is lost. Why this could happen?