BLF for trunk channels

digiteltlc · October 9, 2022, 10:06pm

Is there a way to get a BLF-like indication for a specific sip channel in use on a trunk or at least an indication of all available channels busy ?

david55 · October 9, 2022, 10:22pm

Channels on SIP “trunks” only exist during a call; they have no permanent identity that one could associate with a BLF lamp.

At least at the Asterisk level you can define a number of active channels that corresponds to a busy, rather than an in-use, state (and might correspond to a provider’s commercial limit):

github.com

asterisk/asterisk/blob/master/configs/samples/pjsip.conf.sample#L728


      
                                  ; needs to be specified in the codec allow list
                                  ; (default: "no")
          ;inband_progress=no     ; Determines whether chan_pjsip will indicate ringing
                                  ; using inband progress (default: "no")
          ;call_group=    ; The numeric pickup groups for a channel (default: "")
          ;pickup_group=  ; The numeric pickup groups that a channel can pickup (default:
                          ; "")
          ;named_call_group=      ; The named pickup groups for a channel (default: "")
          ;named_pickup_group=    ; The named pickup groups that a channel can pickup
                                  ; (default: "")
          ;device_state_busy_at=0 ; The number of in use channels which will cause busy
                                  ; to be returned as device state (default: "0")
          ;t38_udptl=no   ; Whether T 38 UDPTL support is enabled or not (default: "no")
          ;t38_udptl_ec=none      ; T 38 UDPTL error correction method (default: "none")
          ;t38_udptl_maxdatagram=0        ; T 38 UDPTL maximum datagram size (default:
                                          ; "0")
          ;fax_detect=no  ; Whether CNG tone detection is enabled (default: "no")
          ;fax_detect_timeout=30  ; How many seconds into a call before fax_detect is
                                  ; disabled for the call.
                                  ; Zero disables the timeout.
                                  ; (default: "0")

I don’t know how easy it is to access this information with through the GUI.

BlazeStudios · October 10, 2022, 1:33pm

You would need to create a hint for the trunk and then subscribe to it. That will just tell you if the trunk is in use or not.

digiteltlc · October 11, 2022, 2:17pm

Well… how to do this ? Any documentation ?

BlazeStudios · October 11, 2022, 3:04pm

Documentation for creating hints in Asterisk? Yes, of course there is. You will need to use a custom include context like ext-local-custom so it will be included in the dialplan.

https://wiki.asterisk.org/wiki/display/AST/Extension+State+and+Hints

digiteltlc · October 11, 2022, 7:42pm

Well…i’ll try to understand something about…
Thanks

system · November 11, 2022, 7:42pm

This topic was automatically closed 31 days after the last reply. New replies are no longer allowed.