All things related to multicast

[Bill Owens <>]

At 15:40 -0400 10/3/02, Alan Crosswell wrote:
> (Does
> anyone already have a script lying around to take a list of IPs and
> find out what ASNs they are in?)

No, but I think it would be easier to find them in ARIN's IP network 
assignments list: <ftp://ftp.arin.net/info/current/network.txt> The 
network names aren't always immediately obvious, but most of them can 
be guessed (or you can resort to a WHOIS lookup).

Actually, more interesting would be pulling the MBGP table from your 
Cisco and looking for the prefixes there. Those are the folks who 
definitely ought to be using multicast. . .

> And, I've found the Windows quicktime playback of RTP MPEG1 to be far
> inferior to IPTVs.

Mac QuickTime seems to have some problems over the longer term (tens 
of minutes), sometimes it will freeze either the audio or video and 
then not recover well, if at all. Since I was watching with rtpqual 
at the same time I could confirm that this was not related to packet 
loss, nor did it seem to be anything else I was doing on the system. 
I restarted the viewer (though not the app itself) several times 
during this morning's multicast.

QT 6 also has a really annoying 'feature' of speeding up or slowing 
down the audio to get it back in sync with the video after packet 
loss. It would make a great deal more sense to just drop some frames, 
IMO, but I haven't found a way to turn this off.

On the bright side, QT with the MPEG-2 decoder add-on seems to do a 
great job, at least with a reasonably powerful machine to run on. . .

Bill.