[AG-TECH] What's typical loss on multicast video/audio?

[John I Quebedeaux Jr]

I have been reporting to my networking staff that I've been seeing 
losses on the order of 1-15% on my incoming multicast video/audio when 
participating in events and that those participating do report that 
they see some loss coming from me as well. Sometimes its only around 
2-3% on average - other times its 5-10%.. and jumps up and down. This 
happens regardless of the node I operate (we have a permanent 
installation in one building and a PIG in another building).

Testing, by inserting our PIG into various points into our campus 
network and observing the general trend in our venue with some helpful 
participants and by general observation in the AG Lobby, seems to 
indicate that while we have a little loss (<1%) across core 
backbone/network enforcer/intrusion detection device - we have a 
greater loss coming from our state network. They tell me we're the 
first in our state to utilize multicast on the network... so perhaps 
there are some issues still to be worked out.

The question my network guy asked me was if this loss was typical or 
atypical of what other sites doing Access Grid/Multicast activity 
usually see. I would maintain that it isn't.... but have to ask the 
question out there for a reality check.

Lately, it seems, that 3 out of 4 events I run are with sites that have 
multicast issues so our quickbridge comes in real handy. For those 
where we do have multicast connectivity - this missing packet loss (as 
reported on the vic rtp stats) is a constant nag.

Thanks for any feedback!

-John Q.
-- 
John I. Quebedeaux, Jr.
Computer Manager / LBRN & CCT / LSU 131 Life Sciences Bldg.
e-mail: johnq at lsu.edu or johnq at cct.lsu.edu / web: http://lbrn.lsu.edu & 
http://cct.lsu.edu
phone: 225-578-0062 / fax: 225-578-2597