Transcoding problems with the new TC400B card

Asterisk Asterisk Support
1

I sold the new TC400B transcoding card of Digium, this card is installing in my system correctly, i have the last versions: Asterisk 1.2.24, zaptel 1.2.19 and libpri 1.2.5.
We are making next test esenario: i have a linksys spa242 registering on Asterisk server with g723 codec this * is public IP address within FW and with g729 codec for outbound calls.

I am seeing the call correctly conected something like that

*CLI> sip show channels
Peer User/ANR Call ID Seq (Tx/Rx) Form Hold Last Message
xx.xx.xxx.xx 0115244216708 1788ed5d4e8 00103/00000 g729 No Tx: ACK
192.168.1.99 201 28c504fa-3e 00101/00102 g723 No Rx: ACK
2 active SIP channels

The problem is the call in g729, on the extencion 201 i am listening very well but on the phone 01152442… i am listening very poor sound looks like bad transcoding, so rare. I dont know.

Please help me.

2

Hi,

I need the next information about TC400b card:
What is the G729 codec format (G729a or G729b or G729 only)?
And same for G723 codec format (G723.1 or G723 only)

I get same problem, I see next in *:
Peer User/ANR Call ID Seq (Tx/Rx) Form Hold Last Message
xx.xx.xx.xx 011524422334 472902296e4 00103/00000 g723 No Tx: INVITE
192.168.1.94 202 90186c8f48a 00101/21350 g729 No Rx: INVITE

Aug 27 11:53:55 NOTICE[23261]: chan_sip.c:3775 process_sdp: No compatible codecs!

3

From the product information page digium.com/en/products/hardware/tc400b.php

The TC400B decompresses G.729a (8.0kbit) or G.723.1 (5.3kbit) into u-law or a-law; or, compresses u-law or a-law into G.729a (8.0kbit) or G.723.1 (5.3kbit).

I suspect your phone is sending 6.3kbit instead of 5.3kbit and that is why it is choppy.