Is anyone actually USING IP QoS?
Alex P. Rudnev
alex at Relcom.EU.net
Tue May 18 20:03:57 UTC 1999
> >Proper inter-domain multicast implementation will make state
> >volume manageable.
> Handwaving. How is it going to make it manageable, exactly?
Just again, there is EXISTING technology, and EXISTING multimedia. I (and
our customers) can get a lot of real-radio and real-video from the
different sources over the world; I can see movies, CNN reports, listen
to audio books, etc etc... No one of this technologies don't use
Multicast in real life.
This meand for me (as ISP) two choices: (1) try to use existing
technology and decrease traffic by unicast caching and replications -
well, it can be done _step by step_, it can be done by the opaque way
(just as WWW caching from the CISCO, but much more effective because
there is less multimedia sources and they provide more traffic every
The other choice is _to build yet another network - multicast network_.
Note - there is nothing except switching caches common with the unicast
routing and management. May be someone ask this service in future, may
be not. Anyone ask RV and StreamVideo service todays. Guess, what 99%
On the other hand, bandwidths increases every day. I need Multicast
service if I provide xDSL for the home apartments over the small city
and try to replace TV by computer. May be it's our future, I do not know
> rate is high. You can think of multicasting as of caching where each
> cache has zero retention time.
> (Caches do not have to delay delivery until the entire file/stream is
Yes. For example, I ask CNN-LIVE-KING realvideo report. I get it
directly, but system can cache this stream on the nearest cache server.
If you ask the same report 5 minutes later, you'll get it directly from
the cache. Just as WWW is cached, with the one exception - in case of
LIVE stream, caching == replication.
What's about LAN networks... Hmm, we have 100Mbit networks here today.
We'll have 1000Mbit networks in the near future. 1 TV stream get (let's
imagine) up to 128, 256, 512Kbit bandwidth. I need 1000 receivers to use
1 (one) Gigabit uplink. Today, I do not need multicasting in my LAN's -
if 10 or 20 customers (I mean intranet, not Internet) ask the same live
stream, they'll get it withouth the problems. Through, it the server
could send packets with the _list_ of recipients, it shoudl be better.
For the comparation, compare with E-MAIL. This service did not built
special address space for the multicast delivering - it use multiple
address records in teh message itself. Very easy and very effective.
> >And, IMHO, any real life conferencing can pretty well live without multicast at all.
> Yep. I would say it is hard to implement a useful multiparty conferencing
> _with_ multicasting. (Yes, i'm fed up with H.323, H.225, H.245, Q.931, RTP,
> G.711, G.729, CSTA, TAPI, Megaco/MGCP, and the rest of the crap).
Aleksei Roudnev, Network Operations Center, Relcom, Moscow
(+7 095) 194-19-95 (Network Operations Center Hot Line),(+7 095) 230-41-41, N 13729 (pager)
(+7 095) 196-72-12 (Support), (+7 095) 194-33-28 (Fax)
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