Hi, I've got the same issue; we've looked into it and the Cisco phones don't have the processing power to host 2 legs of a conference in G.729 mode. My engineer that did the testing assures me that no phone he is aware of is able to do this. If you are aware of a phone that is I would love to know - I'm doing calls over a satellite link and bandwidth matters.
Our solution for a conference requirement is to drop the first caller into a conference room on the Asterisk box, call the third party and drop them into the same conference room, then dial into the confence room myself. Ugly, but it saves having to use G.711 - and once you get used to it... Cheers, Dave. On 3/22/07, Liviu Toma <[EMAIL PROTECTED]> wrote:
I have zero experience with Cisco phones, but I know that other ATAs have this issue as well. Basically the CPU doesn't have enough power to run 2 calls at the same time using g729 compression. Or with some ATAs that have 2 lines, only one at a time can run a 7729 calls, but not both simultaneously. Liviu ----- Original Message ----- *From:* Ian Service <[EMAIL PROTECTED]> *To:* [email protected] *Sent:* Thursday, March 22, 2007 10:39 AM *Subject:* [on-asterisk] Cisco oddity with conference using only g729 enabled Okay, here's a good one... If you take a Cisco and make it g729 only, dial call one on line one, then press Conf, dial another call, it won't connect. You get a reorder message/tone and the console shoots out "No compatible codecs!" So I thought, sure, I guess that makes sense only one g729 call per line on the Cisco, I guess that makes sense. But, you can pick up line 1, make a g729 call, put it on hold, make another g729 call, put it on hold, go to line two and do the same thing, your console will show all four g729 calls at once, though I guess you're not talking on any at the same time, so maybe that's the loop hole. Anyway, I could enable ulaw to make the conferencing work again but if you have ulaw enabled at all, it seems to force the calls to go ulaw first even if g729 is first in priority in the show sip peer xxx output. So you lose the whole benefit of using g729 and saving your bandwidth completely. So, is there a work-around to make g729 work all of the time except when I'm conferencing or make it work all of the time, period? Also, I've only tested this on a 7940, so a 7960 may not have this issue. Thanks in advance for any advice - Ian
