I am working with some third party SIP phones and am having a problem getting bridged line appearances working (shared lines).
According to the phone documentation, it should subscribe to the shared line appearance to get status updates.
I see these updates automatically going out to the Cisco SIP phones with the same shared line. I do not see any subscribe messages going to my third party phones.
I also see CUCM attempt to subscribe to CUPC.
How can I get CUCM to subscribe to my other SIP based devices?