[asterisk-users] Play "blank" sound while VM recording?

[Charles Ulrich]

Greetings,

(Apologies if this is an FAQ, but I've Googled for hours and haven't 
come up with anything yet.)

I have an Asterisk system deployed at a customer's site. It is connected 
to the outside world by a local SIP provider. When someone calls in 
through the trunk to leave a voicemail, Asterisk is not sending any RTP 
packets back through the trunk after the beep is played. This is fine 
and probably should be the expected behavior, except that after 30 
seconds to a minute of not seeing any RTP traffic coming from the PBX, 
the trunk appears to make the faulty assumption that the PBX is gone 
and hangs up the call.

I've called the trunk provider and they said two things. 1) This is 
indeed what their trunk was programmed to do. 2) No, they won't change 
it.

We're working on switching the customer to a trunk provider with a bit 
more clue, but in the meantime, how can I have Asterisk play an empty 
sound file while the caller is leaving a voicemail message just to keep 
the RTP traffic flowing? This installation of Asterisk was designed by 
someone else and I have limited personal experience with Asterisk 
configuration files, so an example would be appreciated if possible.

Thanks!

-- 
Charles Ulrich
Ideal Solution, LLC -- http://www.idealso.com