One of my remote branches has 7 7942s plugged into a 2960 POE and then to a 2901. The computer are connected to the telephone tandum.
1.All the phones dont drop at the same time (maybe 2 or 3 together)
2.The VPN Tunnel never drops when the phones lose the CUCM.(Computers are still online and able to see the network on other side of tunnel)
3.The computer that is connected to the dropped phone does not lose connectivity to the inside network or thru the vpn tunnel (whether in fallback mode or connected or in transit)
4. when a couple of phones are down, I can reach both CUCMs. (Publisher and Subscriber)
Any help would be appreciated.
Try to do wire shark and see if you can capture anything.
Its looks like keep live message dropping some where before they reaching phones. Is there high utilization on site?
Check if any firewall filtering packets.
Phone reboots itself and tries to register again. Check interface if there is any watchdog timers error.
Please do rate if the given information helps