I’m getting some peers showing as Unspecified in the CLI.
255/255 (Unspecified) D Auto (No) No A 0 Unmonitored
This is happening intermittently to numerous peers. Sometimes they are ok, sometimes they are like this. When they are ‘Unspecified’ they won’t accept calls, but can call out.
Trying to dial an extension in this state results in:
Unable to create channel of type 'SIP' (cause 20 - Subscriber absent)
No, Cisco handsets but with only one line configured.
I’ve downgraded the firmware on the SPA504Gs from 7.6.1 to 7.5.7s and it seems to have solved the problem. For now at least, I will need to keep monitoring it.
That bug above is present in that version of Asterisk.
I’m pretty sure you will continue to have this problem intermittently until you upgrade Asterisk.