Subject: Re: ISP scenarios comments

From: bkhabs <[email-masked]>
Date: Wed, 18 Sep 2002 11:25:52 -0700 (PDT)

Pekka,

>On Wed, 18 Sep 2002 18:25:58  0300 (EEST) Pekka Savola <[email-masked]>
wrote.
> * multicast issues
>   - support is yet a bit .. raw or non-existant.

Are you talking standards or implementations?

>   - there is no MSDP, so there can be only one PIM domain currently

Dave Meyer (MSDP chair) and I have gone around and around on this
issue.  The last time we discussed it the consensus was that SSM was
going to be the dominant multicast environment.  If people really
needed inter-domain ASM support, BGMP would fill that role.  Now,
I am not so sure if BGMP is really worth considering or not given
its complexity.

>   - should we focus on SSM only

For the short term definitely.  The key is going to be getting
vendors to support MLDv2 and PIM-SM with SSM support ASAP.

The nice thing about the MSDP spec is that in order to make it
IPv6 capable, three new IPv6 TLVs and the rest of the machinery
should stay the same.

Regards,
Brian

---

From: Pekka Savola <[email-masked]>
Date: Wed, 18 Sep 2002 21:34:22 +0300 (EEST)

> Are you talking standards or implementations?

Both.

As for standards, there is the problem with MSDP.  Another partially 
related one is related to site-local group scoping.  There needs to be 
some feature like 'bsr-border' to site-local scopes to work properly 
inside only one PIM domain, I think.

I had some intention to write a short draft on these open issues, but the 
idea is still waiting at wg chairs'/AD's inbox (or /dev/null, possibly).

> I am not so sure if BGMP is really worth considering or not given

I agree.  Main use of ASM is videoconferencing, and I believe this could 
be done adequately by one SSM "hub".

I believe BGMP hasn't been implemented by anyone.
 
> For the short term definitely.  

I believe most don't realize that's the only option at the moment.

> The key is going to be getting

Yes.

> IPv6 capable, three new IPv6 TLVs and the rest of the machinery

It's good to hear that.

-- 
Pekka Savola                 "Tell me of difficulties surmounted,
Netcore Oy                   not those you stumble over and fall"
Systems. Networks. Security.  -- Robert Jordan: A Crown of Swords

---

From: Brian Haberman <[email-masked]>
Date: Wed, 18 Sep 2002 17:12:58 -0400

Pekka,

> inside only one PIM domain, I think.

I brought up the issue of site-locals and PIM in a PIM for v6 draft a
few years ago.  The PIM group came to consensus that in order to use
site-locals in certain PIM messages (e.g. C-RP or Bootstrap) then a
PIM domain border MUST be the same as the site-local border.

That draft was eventually merged into the new pim draft.

> I believe BGMP hasn't been implemented by anyone.

And I don't expect anyone to anytime soon.

> I believe most don't realize that's the only option at the moment.

Agreed.  The interesting thing is that, just like in v4, multicast
in v6 is lagging in development effort.

> > IPv6 capable, three new IPv6 TLVs and the rest of the machinery

Another possibility is whether or not RFC 3306 can be exploited to
help with the issue of RP location and such.  Haven't had much time
to look into that though.

Brian

---

From: Pekka Savola <[email-masked]>
Date: Thu, 19 Sep 2002 04:19:43 +0300 (EEST)

> That draft was eventually merged into the new pim draft.

Ok; this is still a bit problematic with the one PIM domain requirement.. 
:-/

> in v6 is lagging in development effort.

Yes.  This is sad as SSM video broadcasts could be one "killer" 
application for IPv6 (it would be available for v4 too.. :-)

> to look into that though.

This might be an interesting point to develop more.  It's quite possible
if we can hard-code assumptions about address assignment for the RP there.  
Possibly through an additional bit flag in the address. This would have to
go to the PIM implementation then, though.