FOOD FOR THOUGHT Feasibility of Insta-conference

[David L. West]

I'm trying to develop a "quick conference" routine, because some phones have an easy way to conference and some don't. I want a consistent UI across devices, hence this.

The code should grab all the active channels for a given extension and transfer them all to a MeetMe conference, then join that MeetMe conf itself. Then I'd map that to a feature code so users could just do *88 (or whatever) rather than have to initiate a transfer for each line they have active.

Trying to think it through, I dialed into my Asterisk phone from two outside lines and then looked at core show channels and see this:

a) SIP/inboundtg-000000 s@macro-dial:7 Up Dial(SIP/1000
b) SIP/inboundtg-000000 s@macro-dial:7 Up Dial(SIP/1000
c) SIP/1000-000000d6 s@macro-dial:1 Up AppDial((Outgoing Line))
d) SIP/1000-000000d2 s@macro-dial:1 Up AppDial((Outgoing Line))

Makes sense to me: two channels for each leg of the call. I can use channels() to get the list of channels that have 1000- in them and then use ChannelRedirect() to throw them to a place in the dialplan that'll send them to MeetMe(1000).

But then I realized those last two channels (c & d) are the legs going to my softphone, and the ones I want (a & b) are the other two. So I think what I need is to get the ${BRIDGEPEER} for c & d. The following pseudocode forms in my fevered brain:

cList = ${CHANNELS(1000-)}
for each channel...

bridgedchannel = importvars(channel.BRIDGEDPEER)​

ChannelRedirect(bridgedchannel,meetme(1000))​

end
MeetMe(1000)

And presto, all parties are in a MeetMe conference. Coding in the AEL always takes me longer than I think it should, so I wanted to run this by somebody before I start hacking on it. Not looking for somebody to do the work, just for somebody to say "yeah, that oughta work" or "are you nuts?".

 

[David L. West]

Because I am a strange person, I stayed up late writing code to do this, failed, and here prostrate myself to the community looking for ideas.

I pointed *5 to the following macro.

[macro-instaconf]
; Get the extension (eg 1000) and get all channels for that extension
exten =>s,1,Set(cls=${CHANNELS(${CALLERID(number)})})
; Replace spaces with commas for easier parsing
exten =>s,n,Set(cls=${REPLACE(cls," ",\,)})
exten =>s,n,NoOp(==================== MASTER PROCESSING CHANNELS FOR ${cls} ========================"
; Get the next channel, if blank goto end
exten =>s,n,set(n=1)
exten =>s,n(top),Set(c=${CUT(cls,\,,${n})})
exten =>s,n,GotoIf($["foo${c}"="foo"]?end)
; Get the bridged peer for that channel
exten =>s,n,ImportVar(bc=${c},BRIDGEPEER)
; Save the channel name and original extension to the db
exten =>s,n,Set(dbk=${bc})
exten =>s,n,Set(DB(instaconf/${dbk})=${CALLERID(number)})
; Redirect the bridged channel into an extension that will join a confbridge
exten =>s,n,NoOp(===== INSTACONF MASTER ON ${c} REDIRECTING ${bc}, n=${n} ======)
exten =>s,n,ChannelRedirect(${bc},from-internal-custom,8002,1)
; Increment the counter and go back to process any remaining channels
exten =>s,n,Set(n=$[${n} + 1])
exten =>s,n,Goto(s,top)
; Once we've processed all channels, join the conference
exten =>s,n(end),NoOP()
exten =>s,n,NoOp(==== MASTER JOINING CONF CHANNEL ${CHANNEL} ====)
exten =>s,n,Set(CONFBRIDGE(user,admin)=yes)
exten =>s,n,ConfBridge(${CALLERID(number)})

The 8002 extension the ChannelRedirect points to does this

exten => 8002,1,NoOp(==============INSTACONF BEGIN GUEST ${CHANNEL}==================)
exten => 8002,n,Set(m=${CHANNEL})
; Retrieve the extension number from the database and remove that key from the db
exten => 8002,n,Set(confid=${DB(instaconf/${CHANNEL})})
exten => 8002,n,DBdel(instaconf/${CHANNEL})
; Join the conference
exten => 8002,n,ConfBridge(${confid})
exten => 8002,n,NoOp(==============INSTACONF END GUEST ${CHANNEL}==================)

Then when I call into this from two outside lines and do a *5 from one of them, this happens (cutting out 99% of the output and just showing the NoOp debug lines)

NoOp("SIP/10001-0000006b", "===== MASTER PROCESSING CHANNELS FOR SIP/10001-00000067,SIP/10001-0000006b ========="") in new stack
NoOp("SIP/10001-0000006b", "===== INSTACONF MASTER ON SIP/10001-00000067 REDIRECTING SIP/inboundtg-00000066, n=1 ======") in new stack
NoOp("SIP/10001-0000006b", "===== INSTACONF MASTER ON SIP/10001-0000006b REDIRECTING SIP/inboundtg-0000006a, n=2 ======") in new stack
NoOp("SIP/10001-0000006b", "==== MASTER JOINING CONF CHANNEL SIP/10001-0000006b ====") in new stack
== Spawn extension (from-internal-custom, 8002, 1) exited non-zero on 'SIP/inboundtg-00000066' in macro 'dial'
== Spawn extension (from-internal-custom, 8002, 1) exited non-zero on 'SIP/inboundtg-00000066' NoOp("SIP/inboundtg-00000066", "==============INSTACONF BEGIN GUEST SIP/inboundtg-00000066==================") in new stack

Augh. The redirect is executing (as evidenced by the 2nd and 3rd lines above), but the 8002 only executes once and stops executing at the second-to-last line where it goes to ConfBridge.

 

[David L. West]

Ok, ConfBridge is the fly in the ointment here. Replaced it with:

Dial(SIP/[email protected],60,D(wwwww<host or participant code>#))

And it works! I get two people on the line, *5, and in a few seconds we're all conferenced together. Still some kinks to work out, but I think I'll get there. Next up: implement my own SIP conference bridge so I don't have to use an external one.