The following is the topology.
CCM servers,V5 centralized deployment. Around 30 sites are using this call managers over WAN. More than 3000 phones are there.
*Phones were started to resetting and the phones are stable after few reset.
*But the sites(around 6 sites) are started to report that the calls are not working. Found that the calls are not hitting the gateway, bounced the PRIs(for 6 sites) then the calls are started to works. I dont know wat affected the PRIs.
There is no WAN bounce
There is no MGCP fall back
None of the phones tried to register to the gateway.
Last failover time and Last switchback time are few weeks back
Last MGCP Fallback start time and Last MGCP Fallback end time: are few months back.
There is no PRI bounch
did any faced the same problem and can any one help me to isolate the exact issue.