There you go. SSM would be a great solution. Who the hell supports
it, though?
We still get back to the issue of large scale market acceptance. High
take rate will be limited to the more popular channels, which are run
by large media conglomerates, who are reluctant to let streams out of
a closed network.
Gian Anthony Constantine
Senior Network Design Engineer
Earthlink, Inc.
Office: 404-748-6207
Cell: 404-808-4651
Internal Ext: x22007
[EMAIL PROTECTED]
On Jan 10, 2007, at 12:08 AM, Sean Donelan wrote:
On Tue, 9 Jan 2007, [EMAIL PROTECTED] wrote:
Multicast streaming may be a big win when you're only streaming
the top
5 or 10 networks (for some value of 5 or 10). What's the performance
characteristics if you have 300K customers, and at any given time,
10%
are watching something from the "long tail" - what's the
difference between
handling 30K unicast streams, and 30K multicast streams that each
have only
one or at most 2-3 viewers?
1/2, 1/3, etc the bandwidth for each additional viewer of the same
stream?
The worst case for a multicast stream is the same as the unicast
stream, but the unicast stream is always the worst case.
Multicast doesn't have to be real-time. If you collect interested
subscribers over a longer time period, e.g. scheduled downloads
over the next hour, day, week, month, you can aggregate more
multicast receivers through the same stream. TiVo collects its
content using a broadcast
schedule.
A "long tail" distribution includes not only the tail, but also the
head. 30K unicast streams may be the same as 30K multicast
streams, but
30K multicast streams is a lot better than 300,000 unicast streams.
Although the long tail steams may have 1, 2, 3 receivers of a
stream, the Parato curve also has 1, 2, 3 streams with 50K, 25K,
12K receivers.
With Source-Specific Multicast addressing there isn't a shortage of
multicast addresses for the typical broadcast usage. At least not
until
we also run out of IPv4 unicast addresses.
There is rarely only one way to solve a problem. There will be
multiple
ways to distribute data, video, voice, etc.