[Asterisk-Users] Multiple gateways for same dial pattern

[Adi Linden]

Hi,

How can I setup Asterisk to place calls if the same dial pattern can be
routed through several PRI gateways. I have one way that I tried:

    exten => _9737XXXX,1,Dial(SIP/${EXTEN:1}@172.17.99.5)
    exten => _9737XXXX,2,Dial(SIP/${EXTEN:1}@172.17.99.6)
    exten => _9737XXXX,3,Dial(SIP/${EXTEN:1}@172.17.99.7)
    exten => _9737XXXX,4,Congestion
    exten => _9737XXXX,102,Busy
    exten => _9737XXXX,103,Busy
    exten => _9737XXXX,104,Busy

So what happens is that if all channels on 172.17.99.5 are in use calls
are routed to 172.17.99.6 and if all channels are in use to 172.17.99.7.

One of the problems I am experiencing is that if the gateway goes away,
crashes or otherwise becomes unreachable, Asterisk tries to establish a
session for almost 60 seconds before continuing with the next gateway. If
I add a timeout to the dial command is also applies to busy signal, which
is not suitable either.

Any suggestions?

Thanks,
Adi