I have setup a Polycom Soundstation IP 6000 (Generic SIP), and it works, displays caller/called names, works great, but drops the call randomly. We have never gotten a call to last more than 5 minutes. This goes for internal and external calls, including internal calls to other IP sets (Mitel 5330) on the same controller.
I have setup the SIP Capabilities to:
Disable Reliable Provisional Responses (Yes)
Force sending SDP in initial Invite message (Yes)
Suppress Use of SDP Inactive Media Streams (No)
Renegotiate SDP To Enforce Symmetric Codec (No)
Allow Device To Use Multiple Active M-Lines (Yes)
based on various readings on the internet. And since I cannot logon to MOL, I cannot check the knowledgebase for the guide on Mitels site on exactly how to set it up.
But hopefully, someone might recognize this dropped call bit, and know whats going on. Speech path is fine, network is fine, calls have lasted anywhere from 2 seconds to 3 minutes, 27 seconds. Also, immediately after the call is dropped, and both parties hang up, when trying to call the polycom back, we get a reorder and out of service message. The Polycom will pretend to make a call, but just sit there. Retrying, it eventually will connect back up.
So pure guess is that is dropped communication to the controller for some reason? Are there any good logs on the Mitel I can look at? The "All Maintenance/Software Logs" are kind of useless for this issue.