[asterisk-users] Queue announcements and MOH blanking out on calls from PSTN over IAX2

[Raj Mathur ( राज माथुर )]

Hi,

Problem with Asterisk 1.6.2.9 on Debian Squeeze.

* Infrastructure

We have two servers, SIP and Dial.

The SIP server handles SIP clients; it also receives incoming PSTN calls 
from the Dial server and makes outgoing PSTN calls on the Dial server.

The Dial server is connected to multiple 4-port Redfone devices for 
handling PSTN incoming and outgoing calls.  Outgoing calls always 
originate from and incoming calls always terminate at the SIP server.  
SIP and Dial servers are connected over IAX2.

Normal incoming and outgoing have been working fine for many months now 
on this setup.

* Problem

We recently enabled caller queues on the SIP server.  Queue functions 
are working fine.  Local (on SIP server itself) callers get periodic 
position announcements and MOH while they wait for the call to be picked 
up.  Once an agent picks up the call, the caller and agent can talk 
normally.  Tried with an IAX2 client (instead of SIP) and that works 
fine too.

Callers coming in from the PSTN (through the Dial server, over IAX2) can 
also talk normally after an agent has picked up the call.  However, 
callers from the PSTN get the announcement and/or MOH blanked out after 
a random period of time, typically 5-10 seconds.  This often happens in 
the middle of the queue position or thank-you announcement.

After the blanking out, the call is still alive, queue functions are 
working, and if an agent picks up the calls s/he can talk normally to 
the caller.  However, blanking out of the MOH/announcement makes the 
caller think that the call has been dropped, and they hang up before an 
agent answers.

Debug logs show that Asterisk is playing the MOH and announcement files 
continuously even though the caller cannot hear them.

Unable to figure out why the blanking happens ONLY on incoming calls 
from the PSTN.  Any help appreciated.

Regards,

-- Raj
-- 
Raj Mathur                raju at kandalaya.org      http://kandalaya.org/
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