[Asterisk-Users] Zap call bridge drops randomly

[Rich Adamson]

> We have a call redirection system setup inhouse to send calls from an
> incoming line on a T1 to an external dialed out number:
>   Zap(call comes in) -> Asterisk -> Zap(call dials out)
> 
> The call comes in on a Robbed-bit T1 (d4/ami EM Wink) and goes out on a PRI.
> We are using Asterisk release 1.0.5
> 
> Randomly the calls will drop less than a minute into the call. The Debug
> messages at the end of the call always say something like this: (incoming
> call on 58, outgoing on 73) 
> 
> Feb 21 11:37:28 DEBUG[16804]: Exception on 63, channel 58
> Feb 21 11:37:28 DEBUG[16804]: Got event On hook(1) on channel 58 (index 0)
> Feb 21 11:37:28 DEBUG[16804]: disabled echo cancellation on channel 58
> Feb 21 11:37:28 DEBUG[16804]: Unlinking slave 73 from 58 
> 
> The strange thing is that the person that called in did not hang up, in fact
> they are usually talking when this call goes dead. Only about 10% of the
> calls that redirect have this happen to them, and it seems to be random as
> to which ones drop. Calls that dial out on either T1 and calls that come in
> and are not redirected never seem to have these problems.
> 
> I have callprogress=no and busydetect=no but that doesn't seem to help.
> 
> Anyone have an idea on this?
> 
> Is there any way to make Asterisk less sensitive to hangups if that's even
> the cause?
> 
> Just looking for some feedback before I post on the bugtracker.

You might try:
busydetect=yes
busycount=6

in the top section of zapata.conf and see if that helps. I've not
tried this on a T1, but it certainly clears up the same issue on
the TDM pstn lnterfaces.