Taken from this thread: http://www.freepbx.org/forum/freepbx/users/queues-sip-local-channel-bugs
I am encountering the same behavior as discribed there. I am using PIAF 126.96.36.199 with Asterisk 188.8.131.52 and FreePBX 184.108.40.206.
Noticed quite a few peculiarities when using either SIP or Local Channels in Queues.
I am using Elastix 2.03 with Asterisk 220.127.116.11 and Freepbx 18.104.22.168
If I use Local Channels in Queues setup through FreePBX, the phones aren't send SIP Cancel Reason so they all log a missed call when a call is answered on another phone. If I use SIP channels (S200 in freepbx) this works OK. Queue calls are only logged as a missed call when unanswered or time out. If answered elesewhere this doesn't get log on the phone,
Also with Local channels if a device is turned off, it remains in the queue as available to take calls (Not in use). When using SIP channels a switched off device is marked unavailable which is better behaviour.
SIP channel issues:
WIth Sip channels, call forwards are totally ignored in queues even if agent restrictions are set to Call as Dialled. This works OK with local channels,
Alert-Info for distinctive ring is not passed with SIP Channels and phones just use their default ring. This works fine with Local Channels.
So It looks like both SIP and Local channels have their own issues! Are there any fixes for any of the above issues?