I have a customer that wants to register a pair of SX20 running TC6.2.0 to their 8.5 CUCM.
Unfortunately, I can not get them to upgrade at this time.
There is no Phone Template for the SX20, so I am trying to get it registered as a Third-Party SIP )Advanced) endpoint.
I have a user associated with the it on the Call Manager and I am sure that I have the same username and password set in the SIP Authentication 1 section.
But I am seeing a Rejection on the Call Manager and a Failed: 401 Unauthorized on the Home page of the SX20.
Any thoughts on what I might have missed?
Or is there a device file that I can get them to load to add the SX20?
May have to open TAC case if can not get this figured out.