As I understand one can configure a sip trunk (to sip provider) directly from the UCM6.1 server, or set the SIP trunk to terminate on Voice gateway (running as IP2IP) gateway. In the latter, we'd run h.323 from voice gateway to UCM6.1 and Sip from Gateway up to provider.
What are the pro's and cons of each method? In our's, we will have the PUB in a collocation facility and SUB at main office. Then there will be another branch office.
Without knowing all the details, I would image that it would be better to run sip trunk off ip2ip gateway at each location (HQ and branch) as if the branch lost connectivity to UCM, it could still use sip trunk in SRST mode. Is my thinking on track?
Any and all pro's and cons would be greatly apprecaited. Found one document but didnt' give granualar details.