[AndrewTD]

Hi,
I would like to be able to direct calls to the first phone in a group that is not already busy. It seemed to me that the ChanIsAvail application was the perfect way to do this - but it just doesn't seem to work as desired.
So in the example below - call Sip/53 unless it is already on a call, then call Sip/52, unless it too is busy.

exten => 66,1,ChanIsAvail(Sip/53&Sip/52|s)
exten => 66,n,NoOp(${AVAILCHAN})
exten => 66,n,NoOp(${AVAILORIGCHAN})
exten => 66,n,NoOp(${AVAILSTATUS})
exten => 66,n,Dial(${AVAILORIGCHAN},${STDWAIT})

I am using the latest version of Asterisk - 1.4.11, and am testing with a mix of phones - Linksys SPA942, Grandstream GXP2000 & Snom 320. All yield similar results - regardless of whether the first phone is in a call or not, ChanIsAvail still returns ${AVAILCHAN} as the first phone in the list - in this case Sip/53. From the console :-
-- Executing [66@internal:1] ChanIsAvail("SIP/50-170f5b00", "Sip/53&Sip/52|s") in new stack
-- Executing [66@internal:2] NoOp("SIP/50-170f5b00", "SIP/53-170f9e30") in new stack
-- Executing [66@internal:3] NoOp("SIP/50-170f5b00", "Sip/53") in new stack
-- Executing [66@internal:4] NoOp("SIP/50-170f5b00", "0") in new stack
-- Executing [66@internal:5] Dial("SIP/50-170f5b00", "Sip/53|20") in new stack


Can anyone tell me how to get this working as desired?
Thanks.

[chandave]

Originally Posted by AndrewTD

Hi,
I would like to be able to direct calls to the first phone in a group that is not already busy. It seemed to me that the ChanIsAvail application was the perfect way to do this - but it just doesn't seem to work as desired.
So in the example below - call Sip/53 unless it is already on a call, then call Sip/52, unless it too is busy.
:
Can anyone tell me how to get this working as desired?
Thanks.

ChanIsAvail is not a solution to tell you conclusively whether the channel is busy or not, it is primarily to tell you whether it would be possible to send a call there. Whether that call would end up being accepted or not is entirely up to the peer that we send the call to, and they could easily reject the call even though they do not appear to be 'busy'.
So: If you want to use ChanIsAvail to determine whether the SIP peer is known and registered, it will work fine. If you want to use it for limiting simultaneous calls to the peer, it will not work reliably for you.

Asterisk cmd ChanIsAvail - voip-info.org

I tried using call-limit and Chanisavail, but it's broken in SIP. inuse gets applied only to peers, and when it gets an incomming call that is not answered it gets decremented and doesnt stay the same, which is a bug.
You should consider using groups instead.

Also from the above URL.

See ya...

d.c.

[AndrewTD]

Thanks for that response D.C.

I had seen and read through that particular article. I tried setting call-limit on the phone's sip.conf settings, it appeared to make no difference i.e. even when set to 1, and having a live call, then chanisavail still reported that phone as being available.

Has anyone succeeded in getting a simple config working that sends a call to the first of a list of Sip phones that is not "in use"?

I started to look into the "group" thing - but it seemed to get fairly complex fairly quick!

It seems to me that many people must want to be able to do what I am trying to do here - someone out there has probably figured out how to do it.

Please share the good news with us!
Thanks.