When a call is received especially through SIP trunk, calling party SIP URI's domain portion is getting changed to @cucmip. This blocks the user from returning the call using the recent calls.
How to disable CUCM from changing the domain portion of the calling party identification. Other end of the SIP trunk is a expressway and the exp call history shows that the source has the full sip URI correctly. It seems CUCM is changing the domain portion. Am I missing any configuration.
Yes, it is incoming call to CUCM from expressway (originated from Skype for Business) and terminates at SX20 video endpoint. Yes, there are SIP route patterns for outgoing calls in CUCM to expressways. There are no issues with outgoing caller identification.
The issue is only for incoming calls to SX20 where it changes the firstname.lastname@example.org to email@example.com where 100.100.100.100 is the cucm ip. Because of this, we cannot use the missed/received call information to dial the caller back.