It depends on your infrastructure if you use h323, if you use a VCS the signaling will
always be handled via the VCS only media might be send directly in between endpoints.
Not sure if the media ip is logged somewhere on the endpoint, but you should find that out
when you are in the call, but that can also be the gk if assent / h.460.18 is used.
The right to place to look at would be the call control / gk / vcs / ...