The BRI/PRI trunk is not up. In the Asterisk CLI log, you could see the sentence like:
chan_dahdi.c:14361 pri_dchannel: PRI Error on span 0: We think we're the CPE, but they think they're the CPE too.
Or you might meet the log saying both sides are Network role.
How to get the Asterisk CLI logs?
How to Capture Asterisk CLI Logs for Yeasatr S-Series VoIP PBX
How to Capture Asterisk CLI logs for Yeastar Devices
Switch the BRI signaling role to Network/CPE
- S-Series - BRI
- S-Series - PRI
- TB - BRI
- U-Series - PRI
- TE - PRI