Re: New Internet Draft on automatic (end-user) tunneling for SSM

[Marshall Eubanks <tme@21rst-century.com>]

Hello;

My personal feeling, based on talking with a lot of service providers, is that
they will only provide tunnel relays if they are paid to do it. The unicast
traffic that results from tunneling, of course, they will carry without
complaint. Whether paying them to do tunnel relay's
will be cheaper than just doing unicast failover (as Yahoo does now, and we
plan to do soon) is a very open question.

Inktomi sells software to "roll your own" automatic tunnels. I do
not know what level of interest they have, but they must sell some,
as they were promoting it here in SF yesterday. They call it
application layer multicast. It seems to be aimed mostly at
enterprise networks / intranets.

I still do not see how auto tunnels will scale. If my tunnel relay's will only accept a fan-out of 2,
then to serve 2048 people will require 10 generations of tunnels (and about 1000  
tunnel servers). Even
if I accept a fan-out of 5, 2048 people will require ~ 5 generations.
This seems like an awful long chain (with accumulation of jitter, packet loss, etc.) and a
lot of coordination for an actual, workable, product.(Yes, this is what the routers
do for ISM or SSM, but they are designed to do it. They also tend to cost a lot more than
I suspect people want to spend for tunnel relay's.) 

BTW, in conversations with Matt Schmitt (Yahoo/Broadcast.com multicast guy)
I found out that, while interested in SSM, they do NOT want to break ISM to
achieve it, and DO want ISM and MSDP to continue to work for the forseeable
future. He was unaware of the MSDP "black hole" situation caused by the Ramen
worm and by the adoption of SSM only domains, but he certainly did not
view it as acceptable. Their (514, as of this morning) ISM multicasts  
save them a lot of money, and will
continue at least until SSM is adopted everywhere ISM is.

Marshall

Jon Crowcroft wrote:
> 
> In message <Pine.GSO.4.05.10102261052490.18762-100000@kinkajou.arc.nasa.gov>, H
> ugh LaMaster typed:
> 
>  >>UMTP seems like a lot of work to develop/debug/deploy.  I think
>  >>the same level of effort applied to deploying native multicast
>  >>might bring more multicast users online.  Has anybody attempted
>  >>to survey the Tier-2/3 providers about what they think about
>  >>UMTP multicast vs. native multicast?
> 
> good question - they are the main sticking point given  a lot of tier
> 1 are doign native multicast
> 
> my personal intuition is that "akamizing" auto-tunneled multicast
> across them is the best way
> 
> but its a zero sum game:if we succeed, they will either run native
> multicast soon after, or block the tunnels.....so whatever we do, it
> better be code first, and standards later (of ever)
> 
> 
>  cheers
> 
>    jon

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