- Firmware version: Any
- Model: S-Series
The calls drop exactly in one minute once they establish successfully though the global max call duration(s) is set as 0 which disables the limitation.
The PCAP log shows S-Series PBX sends out the BYEs to Phones which causes the call drop. There is only a brief hangup reason, Q.850; cause=16 which means Normal Call Clearing:
Asterisk CLI log shows normal as well.
Fortunately, we find the extension max call duration(s) is set as the 60s which has a higher priority than global max call duration in General>Preference. This case teaches us to check the basic settings before everything.
Disable the extension max call duration(s) and the issue is gone.