I am having a problem with SIP phones in my environment. The phones themselves are from Lifesize (part of a Lifesize room 200 and Lifesize team 200 units) setup as SIP phones. I am running UCM 6.1.3, a 3745 and a VG200 setup as h.323 gateways to the PSTN. All inbound and outbound calls hit the 3745 first and roll over to the vg200 if necessary. I am using the UCM publisher/master as the SIP proxy.
The phones work great for all internal calls (both to and from the devices and to and from all our standard Cisco endpoints). The video conferencing on the Lifesize units also works perfectly.
The issue arises when I attempt to make a standard voice call from the units to the PSTN or when attempting to call the assigned numbers from the PSTN. The outbound calls connect but only outbound audio works. Inbound calls never get presented to the phones.
I feel like I am missing something pretty simple but have been unable to figure out what.
Thanks in advance for any help.