continuous audio/video test request

[Bill Nickless]

At 05:46 PM 4/6/2000 -0500, Stuart Levy wrote:
> > But when we went to one site transmitting
> > continuously for more than a couple of minutes, we started seeing
> > occasional dropouts.
>
>It could be interesting to *time* the occurrence of the dropouts.
>I've several times seen bursts of heavy loss occurring at regular
>intervals -- like 70 seconds, or 5 seconds -- as though some router
>were being periodically flooded with something (routing update traffic?).

Exactly right.  There are a number of possible protocol-related periodic 
issues:

  - IGMP querier brokenness
  - PIM-SM timeouts
  - MSDP timeouts
  - DVMRP routing table dumps
  - M-BGP table flaps

Each of these has their own period, so knowing the period of the dropouts 
helps find the problem.

But the time to trace down the problem is *NOT* while you're trying to 
present a demo to your funding agency representative!  Instead, you need to 
run an audio source for minutes on end to detect the problem while in test 
mode.

===
Bill Nickless    http://www.mcs.anl.gov/people/nickless      +1 630 252 7390
PGP:0E 0F 16 80 C5 B1 69 52 E1 44 1A A5 0E 1B 74 F7     nickless at mcs.anl.gov