hi,

--- Jimmy Miklavcic wrote:
>-My boss and I think that the bandwidth is the key issue here.  25 video
streams, all transmitted at a rate near 100 kb/s...that's a total around 2.5
Mb/s, just under the capability of two T1s.  Is this an accurate estimate of the
per-stream video bandwidth (100 kb/s)?
>
The minimum connection is 100Mb/s.
--- end of quote ---

100Mb/s??? for what? not sure what is meant here, but don't let this figure put
anyone off.

our I2 pipe is only 60Mbps, way more than we need for typical conferences. we
usually need 10-15Mbps of "clean" bandwidth for what have done for the past
couple of years.

my impression is that typical per stream bandwidth tends to be around
250-300Kbps for video, so 25 streams would be about 6-7Mbps aggregate required
bandwidth for the Lobby.

for actual two way events you're talking about 250Kbps video plust 250Kbps audio
per stream typical minimum so that leaves you with half the streams for the same
bandwidth. 

of course these are minimums and can increase quite a bit depending on how many
sites up their quality of video. i tend to send double or triple these minimums,
so use more bandwidth than "necessary" and ongoing developments in AG modules
suggests higher bandwidth requirements are coming if you want to do higher
quality video streams.

of course, we haven't even mentioned the bandwidth required for shared apps
(though i think that is small, but then there is the visualization component
which could be really demanding :-)

-gurcharan
=================================
Gurcharan S. Khanna
Associate Director
Research Computing
Dartmouth College
603-646-1644
http://research.dartmouth.edu
http://www.dartmouth.edu/~gkhanna