multicast (was Re: Readiness for IPV6)

Tue Jul 9 14:39:35 UTC 2002

On Tue, Jul 09, 2002 at 03:49:04PM +0200, Niels Bakker wrote:
> 
> > Niels Bakker wrote:
> >> It would also be nice if operators with end users started offering
> >> native multicast.  Although the AMS-IX multicast initiative started
> >> off with lots of enthusiasm, two years later it seems to have died
> >> almost completely.
> 
> * pete at he.iki.fi (Petri Helenius) [Tue 09 Jul 2002, 15:27 CEST]:
> > Most multicast projects go this way. The reason usually being one or more of;
> > A) ISP's want to charge extra for multicast
> > B) No content is being served over multicast
> > C) Firewalls do not pass multicast (usually non-issue on home users)
> 
> Indeed.  I'm personally most amazed that B) companies like shoutcast.com
> (who must be spending fortunes on bandwidth for all their streams)
> aren't pushing multicast more.

	The problem is it's somewhat futile.  Even at the larger providers
there is a great deal of fear at times that Multicast will make the network
unstable.  Then there is the lack of education/cost-benifit on the edges
for a lot of the smaller providers.

	They aren't aware of the savings they can see, consider the
savings too small, don't know how to configure, can't configure,
break the config, etc.. the list goes on and on.

	Then you get the people who are stuck with an upstream
that doesn't know how to speak multicast or operate it.  If you
are a customer of (i'm using this as an example, so don't come
after me) Savvis or InterNap, you use them to reach the "big"
folks.  If they don't have multicast enabled you don't have
many choices unless you talk to someone who doesn't mind
unicasting you a multicast tunnel, or go the commercial
route ala multicasttech.

	Then you do have the above 'firewall' issue to
contend with also, as well as other minor
misconfigurations ... such as enabling igmp
snooping on your switches can make multicast not
work right.. some switch vendors ship this as a default
setting..

	Just a few of the barriers involved.  I do encourage
people to contact your upstream, enable multicast, at least
speak mbgp to them and advertize your prefixes.  Enabling pim
or (msdp if necessary) can be done at a later date and
doesn't require a bgp session flap.   Contact your peers,
ask them if they do multicast.  I've seen the number of
peers that have multicast enabled increase over the past year.

	- jared

-- 
Jared Mauch  | pgp key available via finger from jared at puck.nether.net
clue++;      | http://puck.nether.net/~jared/  My statements are only mine.