[cisco-voip] Part 2: Conferencing Codecs Across WAN

[Rhodium]

Hi Pavan,

I think I understand but want to clarify a few things to make sure I got it if you don't mind...

> 
> Assume phone b1 is in a conference with b2 and a1,
> 

/* So phone b1 initiated the conference and hence this above conference is using the cfb in router B. */


> If a1 adds another party a2 to the conference, (conference
> extension) a new rtp stream would flow from a2 to the cfb in
> site b

/* So a1 then puts the original conference on hold and calls a2, a1 then pushes the cfrn button and a2 joins the cfb in router B because b1 originally invoked the conference. I was under the impression that thought a1 would use its MRGL and hence the cfb would be router A  but it doesnt seem that this is the case in basic mode according to this link as only the conference host can join another participant:

http://www.cisco.com/en/US/docs/voice_ip_comm/cucmbe/admin/6_1_1/ccmsys/a05confb.html

*/

> If a1 places the existing call on hold and creates a new
> conference with a2 and a3, now we have a conference resource
> in site a which has rtp streams from a1,a2& a3. Assume
> that a1 now joins both these conferences together with the
> active call being the second conference call( conference
> chaining), we will end up with conference1 containing b1,b2
> and cfb in site a. Conference2 contains a1,a2,a3 and cfb
> from site b.
> 

/* I am assuming that this is an advanced linear conference as per the definition in the document, so any party can invoke a second conference */


So basically, in advanced conferencing (whether linear or nonlinear), the RTP streams flow directly between the CFBs as well so if I have an example of two conferences in both site a and site b and I conference them in and if the default codec is g729, i can have only one g729 codec stream between the two CFBs conserving bandwidth as each participant is restricted to their own CFB.

Right?

My head does hurt from this...

Jason