How many G729 licenses do I need for 20 concurrent calls?

I have 20 channels G729 license but is not clear to me how many concurrent calls can use with them.
The current setup is with my inbound provider I have enabled G729 only and internal clients are using X-Lite with G711 only.
So my assumption is that I should support 20 concurrent calls (encoded with G729) coming from my inbound provider right?
And between my inbound provider - my asterisk - and my internal clients will be transcoding G729/G711.

But on one single call I have:
sip1*CLI> g729 show licenses
2/6 encoders/decoders of 20 licensed channels are currently in use

And somewhere between 7 and 11 concurrent calls (I think) I receive out of G729 licenses…
Please advise how many licenses do I need for 20 G729 concurrent calls between my provider and my asterisk box with internal clients using G711 enabled softphones.


Are you recording any of those calls? Every time you open a recording session, you’re hooking an audiohook into each leg of the call, and transcoding from G.729 to something else, for the hook. So, for that scenario you describe there, it looks like you have two calls going on, both of which you’re recording.


Hi Malcom,

Indeed I do record those calls. Would that mean that I can only handle 10 G729 maximum concurrent calls in my setup?


If you are recording calls, then you’re using 1 channel for the call-to-call transcoding, and then two more channels (one for each of the legs) for the recording. Thus, if you want to have 20 calls going and record all of the calls, then you’re looking at 60 channels worth.


And if I’m using Mix Monitor = yes, basically as I know with this function asterisk record the call using one leg only not two as with the old function Monitor Join - yes, when there was two recordings , one for in and one for out and then joined.

So with Mix Monitor do I still need 3 licenses for one call? Or is there a possibility in my setup to only double the number of licenses required instead of triple?


You should be able to test that easily enough, but unless I’m wrong, you’re still hooking onto each channel, and transcoding each channel down.

I’ll do, thanks for help.
To be honest I didn’t thought initially about the recording legs.


Hi LG,

I have the same setup with you. I’m using g729 licenses on both sides. g729 on my voip provider and g729 on the sip users.

Provider = g729
SIP User = g729
1 call = 0/2 encoders/decoders of 10 licensed channels are currently in use

Note: I’m also recording the calls with mixmonitor.

Here are other examples with different scenario:

Provider = g729
SIP User = g711 ulaw

LUI*CLI> g729 show licenses
1 call = 1/1 encoders/decoders of 10 licensed channels are currently in use

Provider = g711 ulaw
SIP User = g729

LUI*CLI> g729 show licenses
1 call = 0/3 encoders/decoders of 10 licensed channels are currently in use

In your scenario, you’re out of g729 licenses in doing 7 to 11 concurrent calls with 20 installed licenses because you can only handle 6 maximum. :smile:

To answer your question, in 20 calls you’ll need 60 g729 licenses. I have a tip for you, use g729 licenses on your soft phone so that you can save some. Use Bria or Eyebeam. Xlite doesn’t have it.

I hope this helps you!


Hi Lui,

Thanks! I will have to explore the eyebeam solution too.