[asterisk-users] "Random" all circuits busy now message

[Eric "ManxPower" Wieling]

jan.sarin at securia.se wrote:
> Hi,
> 
> We have quite a large setup working just fine most of the time. We have
> 60 outgoing lines on PRI and we never use all of these lines. But
> sometimes we get the "all circuits busy now" message, seemingly random.
> 
> Sometimes we get it before the call even goes through to PSTN. Sometimes
> after 5 or 6 rings etc.
> 
> It seems that the carrier is signalling something and asterisk always
> interprets this as "all circuits busy now" whilst a old-fashioned
> exchange might say "busy" or "wrong number" or "hangup" etc.
> 
> What might cause asterisk to handle signals like this?

Asterisk does not play these messages by default.  Either you have 
inband signaling set for your PRI or you have set up asterisk to play 
these messages.

When Dial exits it sets HANGUPCAUSE and DIALSTATUS.  HANGUPCAUSE 
contains the Q.931 PRI disconnect cause code.  Your dialplan then must 
decide what to do based on this causecode.

I use macros that I wrote to retry the call if the hangupcause is not 
one of the common, expected hangup causes like busy or normal hangup.