[Asterisk-Users] G.729: Typical usage scenarios

[John Todd]

>Clicking on the "For more information, click here" link on the 
>Digium site nice brings back up the same page I was looking at 
>before, without any additional G.729 information that I can see.
>
>I'm wondering if some kind asterisker out there could provide us 
>neophytes with some "typical scenarios" where that codec would be 
>useful to us.
>
>For instance, I assume that it doesn't gain anything on calls passed 
>out to the PSTN?

Well, if your Asterisk server is right next to your UA (ATA-186) on 
the same ethernet, you don't gain anything - you should stick with 
the ~80kbps G711 codecs which sound better.  If your Asterisk server 
is on a different continent across a 56kbps satellite link, then I 
would suggest that you look into the G729 codec.  People who are 
bandwidth constrained and have multiple UA's connecting from distant 
locations are most likely to benefit from G729.

>Do the Cisco ATA186s have any ability to handle this codec?

Yes.  Set LBRCodec to "3" and then set TXCodec to "3" and RXCodec to 
"3" to set G729

>Perhaps it would be useful if I'm trunking from a FXS port here 
>locally to an FXO port that is connected to a remote asterisk server?

Only if you have critical bandwidth shortages.

>Also, is the license "once in a lifetime" for a given channel?

One-time payment per channel.  No recurring fees.

JT