Hello all. I am experiencing a situation where all of my phones in my CUCM environment randomly reset with call manager yesterday. I opened a TAC case regarding this but the only thing we see in the event logs are phones had to register back with CUCM because of Reason=16. According to cisco this is the definition:
ReasonCode 16: DuplicateRegistration. This means that Cisco Unified CallManager detected that the same device was registered on two nodes at the same time. When this happens, Cisco Unified CallManager sends a restart request to the phone to force the phone to register with only one Cisco Unified CallManager
I cannot figure out why this happened. In our environment we have one CUCM server and a 2911 gateway that acts as a SRST box. We did shut the gateway down to install a FXS card the evening before this started happening. This box also acts as the DHCP server for the phones as well. Call manager did not go down during this install but could this have triggered the phones to register with the SRST box somehow? It has not happened again since the restart yesterday.