Sending empty rtp packets

Asterisk Asterisk Support
1

I run a voicemail service, and I’m running into a situation where the line disconnects after five minutes of leaving a voicemail. It’s not that the voicemail application allow them to leave a longer message, the line just goes dead. This problem happens with my local DID numbers, but not my toll-free numbers and appears to be carrier-related.

The Asterisk CLI indicates the cause of the disconnection is that the user hung up. I’ve tried adding these settings to SIP_Custom.conf, but that hasn’t cured the issue.

rtptimeout=1200
rtpholdtimeout=1800
rtpkeepalive=20

In conversations with Vitelity where I describe what’s going on and that the settings above aren’t working but should, they have said, “We have clients that do exactly what you are doing - They have custom scripts that send out blank/silent rtp packets out every x amount of seconds. Unfortunately I’m not quite sure how it’s done myself or I would definately provide you with the info… i’m sure you could find something if you dig around”.

So, how do you keep the line alive? Because it’s voicemail I can’t play beeps or a recorded message, and the rtp settings aren’t working for me. Thanks.

2

Could you please post your asterisk console messages.

Thanks,
Suresh.

3

This was fixed in 1.2

add
[options]
transmit_silence_during_record = yes

to the top of your asterisk.conf

Ian

4

That did the trick.

I can do some testing, but do you know if technically if that setting replaces the rtpkeepalive setting in SIP.conf? Are they meant to do the same thing?

Thanks!

5

Hi.

Im not sure. You will have to look at the source, but this is the setting that I use, as it works for SIP and IAX

If you go back in Bugzilla you will find the birth of this fix

Ian