I have a new deployment of Cisco BE6K where I have a CUCM Publisher and one subscriber. Also in the deployment are pub-sub of Unity Connection and Cisco IM&Presence. I have 2 cube routers one at each location of the CUCM server with a SIP trunk into each one. Version of CUCM is 188.8.131.5200-28. My problem is this: If I initiate a call from an IP phone to the PSTN (cell phone is what I've used) and then attempt to conference in another IP phone in the same device pool, same region, the conference connects the 2 IP phones and drops the PSTN call leg.
However on the flipside, if I call from the PSTN cell phone used before to the IP phone, then conference in another IP phone the conference will be completed. Any help on this is greatly appreciated. Phones are 8945s, Cubes are Cisco 2921, server is Cisco C220. Entire Cisco network.