Re: ISP scenarios comments (multicast)

[Brian Haberman <bkhabs@nc.rr.com>]

Pekka,

Pekka Savola wrote:
> 
> On Wed, 18 Sep 2002, bkhabs wrote:
> 
> > Pekka,
> >
> > >On Wed, 18 Sep 2002 18:25:58  0300 (EEST) Pekka Savola <pekkas@netcore.fi>
> > wrote.
> > > * multicast issues
> > >   - support is yet a bit .. raw or non-existant.
> >
> > 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 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 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).
> 
> > >   - 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.
> 
> 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.

And I don't expect anyone to anytime soon.

> 
> > >   - should we focus on SSM only
> >
> > For the short term definitely.
> 
> 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.

> 
> > The key is going to be getting
> > vendors to support MLDv2 and PIM-SM with SSM support ASAP.
> 
> Yes.
> 
> > 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.
> 
> It's good to hear that.

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