I believe that this usually means there is no route (either configuration error or the T1/ PRI is down)
Thanks for posting. First, verify with a 'ping' that we can reach the SIP server. Correct any IP address and/or route issue if this fails. Then, I agree that we need to check your voice trunks, trunk groups, and any PRI interfaces. Verify that your voice trunks are connected to the trunk groups as shown in the example for a SIP trunk below.
voice trunk T01 type sip
sip-server primary 188.8.131.52
voice grouped-trunk SIP
accept $ cost 0
If you have a PRI trunk, it should have a corresponding "connected" grouped-trunk as well. Next, I would check all your interfaces with "show interfaces" to verify that your interfaces are up. In particular, your PRI interface should show an active D channel under "Channel Status". If you do not see any issue in any of these places, we will likely need to see your configuration and possibly a debug output of a test call.
We would be glad to review your configuration as a first step, but be sure to remove any passwords, IP addresses, phone numbers, etc. that you do not want public.
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