1. Asterisk CLI log with fax debug
- Firstly, enter the SSH interface and start to debug.
- Enter the commands before you replicate the issue.
- fax set debug on
- fax show settings
- Enter the command after you replicate the issue.
- fax set debug off
2. PCAP capture or Port signal capture
- If the trunk for fax call is SIP or IAX trunk. Try to get the PCAP capture.
- If the trunk for fax call is FXS/FXO, BRI, PRI trunk. Try to get the port signal capture.