G729 weird problem with 2 channels active

Hey all,

I’m having a weird problem (running Asterisk 1.0) when we have 2 concurrent calls active. The first call works perfectly, as designed - however with the 2nd call, they can hear us - but we are unable to hear them.

Let me explain a little more about our system.

We are running an “Auto-Attendant” style system, so when the call comes it, it prompts to press 1, 2 or 3 for each department.
Our handsets are setup with multiple lines, i.e. my primary extension is 701 and the person sitting next to me is 702. I also have, Ext 7101, 7201 & 7301 running off the same phone and same with each other employee here except with the next consecutive number.

When a call comes in for group 1, all handsets in group 1 will ring eg. 7101, 7102, 7103 etc. A person answers the call and will have full communication abilities to the person and everything is fine. When a 2nd call comes in, again all the hansets for group 1 will ring. The next person who now picks up this call will answer it, and seem like they are working correctly. The person on the other end of the line can hear us perfectly, but we are unable to hear them. This occurs with the 2nd call that comes in on ANY group… i.e if there is 1 call active in group 1 and the 2nd call that comes in is directed to group 2 - the problem will still occur.

To add something further into the mix, we have all calls records to a .wav file for security reasons (this has been disabled during diagnostics of the problem) - and both ends of the conversation are being recorded and are being received into the system

We feel that the problem is possibly occuring during the bridging in the G729 codec with the secondary call, however are unable to know if it is or not.

Can anyone provide a possibly solution/workaround or tests that we can perform to move further with this issue?


can i use my first lifeline ? i’ll take output from /var/log/asterisk/full please :smile:

Have you checked that you have enough g729 licences installed? I know it’s obvious, but this has stung me before.

Also, try

CLI> show g729

to see what’s happening during the call (ensure the number of encoders/decoders is as you expect). NB if you are passing g729 straight through (i.e. your phones are g729 and your PSTN link is g729), then you won’t use up an encoder/decoder. Perhaps one of your phones is not using g729 as expected and hence Asterisk is unexpectedly having to do encoding/decoding.

Thanks guys for the suggestions, I’ll get the log file for you, however after running the show g729 command we get the following message under 1 call and 2 calls.

voip*CLI> show g729
1/3 encoders/decoders of 5 licensed channels are currently in use

voip*CLI> show g729
2/5 encoders/decoders of 5 licensed channels are currently in use

What i’ve also noticed is that being in the “asterisk -r” shell, upon the second call being answered by an extension we are receiving the following message over and over again:

Feb 10 12:58:23 WARNING[13119]: codec_g729.c:180 g729tolin_framein: Out of G.729 Decoder Licenses!

I suppose this seems very relevent, however what do you advise if the best resolution. We did purchase 5 G729 licenses and I believe they have been installed correctly.

Thanks again :smile: