[asterisk-users] IAX problem through intermediate asterisk box

[Andrew Hakman]

So no one else has a problem routing IAX traffic through an
intermediate Asterisk server? Does anyone else use Asterisk in such a
configuration?

On Thu, Mar 26, 2009 at 2:45 AM, Andrew Hakman <andrew.hakman at gmail.com> wrote:
> I'm having a problem with IAX running through an intermediate asterisk
> box. Perhaps a small diagram will explain the situation better:
>
> *A ------- [cloud (public internet)] ------- *B --------[cloud
> (private network)]----------- *C
>
> Asterisk server's A, B, and C, are all connected together with IAX
> All asterisk servers are 1.6.0.6
> Server A and B are geographically close, but connected over the public internet.
> Server B and C are geographically far, but connected over a private network.
> (the latency between A and B, and B and C are roughly equal)
>
> Each server has at least 1 phone hanging off of it, with A and C
> having most of the phones (B only has a couple).
> A's extensions are all 1XXX, B's are 2XXX, and C's are 3XXX
>
> Phoning from A to B (or vice versa) works well, as does phoning from B
> to C (and vice versa). Calls can be placed for an indefinite amount of
> time and everything works great.
>
> The problem arises when phoning from A through B to C (or vice versa).
> For the first small amount of time (which can vary on a call to call
> basis, and lasts from 0 seconds to 3 minutes or so) everything is
> fine. After this, the audio in both directions gets garbled, and
> starts arriving in spurts. Once this happens, it continues forever.
> The audio never returns to normal no matter how long you wait.
>
> A to B uses IAX with trunking. B to C is not using trunking
> (dahdi_dummy is not working well on C for some reason - the module
> loads, but no /dev/dahdi is ever created). The same behavior happens
> when A to B is not using trunking either.
>
> Usually only 1 call is being placed at a time. An interesting thing
> happens when 2 testcalls are in progress at the same time though. If
> there's a call from A to B, and a call from A to C is made, once the
> call from A to C becomes garbled, so does the A to B call. When the A
> to C call is ended, the A to B call clears up. Ending the A to B call
> first does not improve the A to C call.
>
> The dialplans are setup so each server passes all non-local extensions
> to it's neighbor.
>
> Hence, for A, the relevant part of the dialplan is
>
> exten => _2XXX,1,Verbose(1|Extension 2xxx)
> exten => _2XXX,n,Dial(IAX2/asterisk_B/${EXTEN})
> exten => _2XXX,n,Hangup()
>
> exten => _3XXX,1,Verbose(1|Extension 3xxx)
> exten => _3xxx,n,Dial(IAX2/asterisk_B/${EXTEN})
> exten => _3xxx,n,Hangup()
>
> For B:
>
> exten => _1XXX,1,NoOp()
> exten => _1XXX,n,Dial(IAX2/asterisk_A/${EXTEN})
> exten => _1XXX,n,Hangup()
>
> exten => _3xxx,1,NoOp()
> exten => _3xxx,n,Dial(IAX2/asterisk_C/${EXTEN})
> exten => _3xxx,n,Hangup()
>
>
> For C:
> exten => _2XXX,1,Verbose(1|Extension 2xxx)
> exten => _2XXX,n,Dial(IAX2/asterisk_B/${EXTEN})
> exten => _2XXX,n,Hangup()
>
> exten => _1XXX,1,Verbose(1|Extension 1xxx)
> exten => _1XXX,n,Dial(IAX2/asterisk_B/${EXTEN})
> exten => _1XXX,n,Hangup()
>
> Is this the proper way to set such a configuration up? Is there a
> better way to call from A through B to C that would work better?
> Anyone else experience total audio breakup after a while with a
> similar arrangement? Why does it work initially for up to about 3
> minutes, then completely fall apart?
>
> Thanks,
> Andrew
>