After some messing around, we finally were able to get a Polycom Trio 8800 registered to the Allworx Connect Server.
Make sure to have your SIP ID, User ID and SIP password from the Allworx 3rd party SIP extension.

Log into your Polycom
1) Go to Line 1 > Identification and enter the Display Name of your choice > enter the address as [email protected] (e.g. *[email protected]) > Set Type to 'Private' > Set Enable SRTP to 'No' > Set Server Auto Discovery to 'No'
2) Go to Line 1 > Authentication and set User Login Credentials to 'Disable' > Set domain to IP address of PBX > Set User ID to User ID set up in Allworx 3rd party SIP handset > Set Password to 3rd party SIP password
3) Go to Line 1 > Outbound proxy and set IP to IP of PBX > Set port to 5060
4) Go to Line 1 > SIP server 1 > Set Special Interop to 'Standard' > Set Address to IP of PBX > Set Port to '5060' > Set transport to 'UDP' > Set Register to "yes'
See screen shot below
[Linked Image from electsystech.com]

Last edited by aweaver; 03/31/20 06:20 PM.

ElectSys Tech LLC
Hosted Phone Systems Solutions Provider
Allworx, Sangoma, FreePBX
Telephone & computer systems in the Jefferson City, Columbia MO area.