North American Network Operators Group

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RE: video distribution

  • From: John Ferriby
  • Date: Wed Jul 14 16:53:44 2004

> I wanted to make a number of video streams available across an IP WAN
> network, I have a couple of options.  Unicast or Multicast.  Unicast isn't
> the most efficient method necessarily so my preference would be Multicast.

Depends on the exact nature of what you are doing and the network(s) in
question.

Some things to think about:

-Are you going to serve a mutlicast-aware audience directly?
-Are you thinking of feeding another server(farm) to retransmit?

Drawing from my own experiences, multicast is great for server-server
distribution.  It is (can be) fantastic for large audiences IFF you
have a stable multicast-happy environment.  IMHO multicast enivironments
just require a bit more care-and-feeding.   Multicast networks
frequently need a strong human proponent too.   Multicast is great
but is counter-intuitive for most support staffs to handle.

I have to be careful here because I could really get on a soapbox.

Unicast is the lowest common denominator and is far easier to deal
with in terms of transport peculularities.   It is the only answer
the makes sense for an on-demand enviroment.  (I've known of
groups to make scheduled multicast retransmissions, but you'd have
to be pretty serious for this in terms of the human dynamic)

-John