Help in understanding utilization of g.729

Greetings all,
We have been running Asterisk in a call center environment for 2 years now with great success on SIP carrier. We are now trying to implement g.729 codec into production and we need a little help in understanding usage.
Here is what we want to accomplish. We use ViciDial in predictive dial out/in campaign. Our carrier uses g.711 and g.729. We are currently configured for g.711. We wish to use g.729 at the carrier level to reduce Internet connection bandwidth load and at the agent phone level to reduce VPN bandwidth load between offices. We purchased Digium TC400B transcoder card. We have the carrier and phones working on g.729 when making manual dial out on dialer and on inbound calls. Predictive dialing out from a list will not pass a connected call to available agent. (It works if I switch carrier to g.711).
My question is this, since my carrier supports g.729 and our SNOM 320 phones support it, do we need to do any transcoding or do we just need licenses?

You only need licences if you do transcoding! However, lots of things can trigger a need for transcoding, e.g. tones, and Originating with the wrong codec specified.

Actually, having purchased the TC400B card you don’t need any additional licenses at all!

The TC400B does not require additional licensing fees for the use of these codecs nor does it require the registration process associated with Digium’s software-based G.729a codec licensing.[/quote]

From what you’re saying it seems the card hasn’t been installed or configured properly. Try running “transcoder show” in an asterisk console. According to the card manual:

[quote]Verify that the TC400 Series is registered with Asterisk by issuing the
following command on the Asterisk CLI.
*CLI> transcoder show
This should display the number of encoders and decoders registered
by the TC400 Series card.[/quote]

Regarding the transcoding - you may need it for a number of things, but I suppose, as a call center you do call monitoring (recording) for any purposes, which requires transcoding.

Thanks for the replies.
We have the card working and have done extensive diagnostic testing as to why when using g.729 at the carrier, predictive dialing from a list will not transfer a connected call to a waiting agent’s meetme room. We have inbound and manual dial from dialer interface working great when using g.729, it just will not pass a predictive dialed call to agent. As stated earlier, if I switch the carrier to g.711, everything works fine. But we really need to use g.729 at the carrier level also.
From all of our testing, it seems that when in full g.729 mode and a predictive dial call is connected that the card is trying to transcode before sending to the agent’s meetme room. The call just hangs up.
This is what led me to ask the question. Yes we do record all calls and also play audio prompts and play recorded messages to answering machines. We really need to reduce overall load on the dialer and Internet connection was hoping to do so with this card.
The Eflo forums have responded with: ‘That’s one of the reasons we recommend the Sangoma transcoding cards instead. They are much faster and more robust and offer ranges of licenses from 30-480 channels. They also offer a lot of configuration options as to how the transcoding works.’

Have you contacted Digium support to make sure the card is configured properly? … roduct.php

Yes. They stated it looks like a problem with ViciDial.