conference calls

[tomchan]

Some design questions. Could you direct me some useful urls which show how conference calls works in the IP telephony environment? How many conference calls can be supported? And let say if I am using G.711 codec and have 60 different office locations try to join the conference, does it mean I have 60 G.711 codec session which will use 60 x 80kbps bandwidth as each G.711 takes about 80kbps?

Thanks.

[irisrios]

Here is an extract of one of the documents available on cisco.com. The hardware and software resources for conferencing give different number of conference calls. Here is a list of it:

Software Conference Limits

- Up to 128 full-duplex streams are configurable.

- 48 users in a single conference or 16 conferencing resources with three users per conference

Hardware Conference

- Catalyst 6000Mixes all conference participants

G.711 or G.723 or G.729a or GSM/FR

- 32 conference participants per physical port.

GSM/EFR

- 24 conference participants per physical port

- Catalyst 4000 (G.711 only)Mixes 3 loudest talkers

- 24 conference participants per physical port

- Maximum of 4 conferences with 6 participants in each.

Also check the following documents for more information:

Cisco DSP Resources for Transcoding, Conferencing, and MTP

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_administration_guide_chapter09186a00801ec5bb.html

Configuring and Using a Hardware Conference Bridge with Cisco CallManager 3.0 and a Catalyst 6000 WS-X6608 Port

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_configuration_example09186a0080114c64.shtml