H323 standalone endpoint calling CUCM VC endpoint

[Flo.Matalis]

Hi Experts,

We have an H323 standalone endpoint and would like to call a CUCM VC Endpoint. Is this possible?

We have an RMS license already on Expressway E. We have tested the CUCM VC Endpoint calling the H323 standalone and it is working fine, but H323 standalone calling to CUCM VC, does not work.

Any replies would be appreciated. Thank you.

[Jonathan Schulenberg]

CUCM will not accept or transmit a call to an unknown destination so your question, especially since you mention an RMS license, is more about VCS/Expressway. From CUCM’s perspective it would be an incoming call on the SIP trunk from VCS/Expressway-C.

https://www.cisco.com/c/en/us/support/docs/unified-communications/telepresence-video-communication-server-vcs/118884-config-vcs-00.html

I suggest starting by seeing how far the incoming call makes it: Expressway-E, Expressway-C, or CUCM. That will help you decide which logs are worth reading closer and/or where to turn up log verbosity levels.