See Number of Used Channels on Grandstream Phone

[lgaetz (Lorne Gaetz)]

If you’re using DAHDI channels, this might help:

How to determine the PSTN line status? is this SLA?

Monitoring a DAHDI channel is easy with a BLF, provided you don’t want the button to do anything when pressed. In the file /etc/asterisk/extensions_custom.conf add lines like these in the existng [from-internal-custom] section: [from-internal-custom] exten=> *00001,hint,DAHDI/1 exten=> *00002,hint,DAHDI/2 exten=> *00003,hint,DAHDI/3 exten=> *00004,hint,DAHDI/4 Reload the dialplan, then program a BLF on your phone with the code “*00001” (no quotes) and the BLF will illuminate whene…