2.5.10 Multicast Last Mile (mlm) Bof

Current Meeting Report

issue.Minutes - Last Mile BOF -  Keyur Patel and Greg Shepard

MLM - a misnomer

Greg - In the enterprise, multicast is easy to deploy, Not so in the 
global Internet, Enabling multicast one network at a time brings you 
nothing. Multicast is all or nothing - either it works or you get 

- provide a multicast only transport solution for content owners
- independent of multicast penetration
- leverage existing deployment

Toerless E. - Thinks that there is no business demand for tunnels

Dae Young Kim  - There are two businesses in Korea (one for massive many to 
many gaming) which use a box for autotunneling if multicast is not 
available. I implemented a common control protocol to locate and do 

The first company is called Media Delivery - video on demand like 

Toerless - Is this application layer multicast ?

Answer - the server and receiver look only at the multicast 
addresses. We want to use any native multicasting available.

Mark Handley - I think what Toerless was trying to say was that there is a 
continuum  between static IP based tunnels and automatic tunnel on a per 
group per source basis.

Lenny G. Regarding demand - A few months back probably the largest 
content provider came out with a proprietary box solution that does the 
tunneling, except it was unicast to unicast.

Greg Shepard - After my NANOG talk two years ago about this, I had major 
content providers come up to me and say "solve this and we are 
interested" and so I think demand is there.

Toerless - I want a service provider to say that they could accept boxes 
that would provide thousands of tunnels automatically.

If you cannot reconstitute an IP multicast packet you do not have a 
network layer tunnel.

Mark Handley - I think that Toerless does have a point here. If there is an 
application that is producing packets with the same source and the same 
port, but different groups, then you need the group address to make 
things work.

Mark Handley - we seem to be confusing how do you set up tunnels versus how 
you use tunnels to emulate ASM with SSM or something similar.

Kevin Almeroth - Is there a consensus that this (tunneling solutions) is 
something that should be done.

Michael  - I tried for 2 IETF's to get a multicast for Yokohama without 
success. I think that this should have been done in 1999.

Mark Handley - There needs to be a business model to deploy this and we 
need to be careful not to set ourselves up for denial of service 

Lenny G. If you could set this up so that people who have not turned 
things on can get multicast, then this would create measurable demand.

Jon Croncroft (?) We should not be doing business model stuff in an 
engineering meeting. MBoneD addresses relatively well the wide area 
deployment, but there are a lot of holes in the last mile - IGMP 
snooping for example - that could be documented.

Michael - We have also had deployment issues with IPv6. Now there is a web 
site for IPv6 tunnels. This just required some smart web designs. Then we 
set up 6to4 which requires no cooperation from anyone else. Is there a 
technology or an idea like that for multicast.

Greg - I agree that the 6to4 transparent solution is what I would like to 

Toerless - I think that the interesting case is where one tunnel 
end-point is a host.

Bill Fenner - NAT's are also an issue. We need some mechanism to get 
across NATs which are common on home networks.

Lucy as Tom Pusateri - We should not change the signaling protocol if at all 

Do not make encapsulation a  requirement.

Do use the router alert bit so that routers in route can trap the joins and 
send the data if they have them.

Dino F. Why do we not start with UMTP and see if it will work.

Greg Shepard - There would need to be tweaks to it, but it's close and 
there is code.

Bill Fenner - If you look at Live.com multikit tunneling it resources the 
packets on the wire using a loopback address so the group address is fine 
but the source is changed.

Dae Young Kim  - video providers with very high quality video cannot 
afford the servers to source high quality

In that way this big ISP talks with a lot of broadcasters and say, why 
don't you connect directly to us. Mostly, the server breaks down before the 
service provider breaks down. They do have a business model here and are 
very much keen on this . The homes that have large bandwidth want video.

Audience member - This gets around the chicken and egg deployment 
problems. Some of the edge devices, DSLAM's for example, do not do a good 
job of supporting mullticast. I think that this is a very good idea and see a 
good case for this.

But, why do transit tunnels not work ?

Greg Shepard - Tunnels are one to one. You may think that you are 
getting a network but you may not be getting much more than one 
interface on some router in their lab.

Dino F. The long term goal is to push multicast out to the edges. In 
unicast you really don't care and you can do host to host or router to host 
or whatever. In multicast you have to be a lot more careful.

Joelja - Our problems are all at the edge. All of our router 
interfaces are multicast enabled. The problems are in switches and hosts.

Eubanks - suggested the OpenBrick / OpenTv model for a simple open source 
network appliance for setting up tunnels.

Dae Young Kim - the box sits at the layer 2, sets up the tunnel and puts the 
multicast onto the local LAN - this box only uses the bandwidth for two 

Radia Pearlman - I don't know why everyone is so focused on a daemon 
working without privileges.  Is it so difficult to get system 
administrators to install an application.

Lenny G. I think that the descriptions of this service as a strong arm 
tactic to beat tier 2's with a clue stick is right on. We need to do this. We 
asked nicely and nothing happened.

Michael - The whole world doesn't have fiber going through their yard. The 
copper is mostly used by regulated providers, and the regulators do not 
care about customer demand.

Audience member # 2 - The response of the regulatory agencies is pure 

Jon Crowcroft - The content providers (as in RMT) have developed boxes to do 
application layer multicast. These are in places that would be natural for 
tunnel end-points, so there may be some commonality of interests here.

Greg - Bill, can you offer us any guidance.

Bill Fenner - You have a mailing list - you need to send out a summary and 
see if you can get something happening on the mailing list.

Toerless - Would this be in MBoneD or somewhere else ?

Bill Fenner - Work can be done in existing places or in new places. We 
don't know what the requirements and solutions are so I can't say where it 
should be.


None received.