Re: WG last call: draft-ietf-l3vpn-ppvpn-mcast-reqts-03

[Thomas Morin <thomas.morin at rd.francetelecom.com>]

Hi Marshall,

Marshall Eubanks:
> > >    The use of globally unique means of multicast-based service
> > >    identification at the scale of the domain where such services are
> > >    provided SHOULD be recommended.  If the ASM model is used, this
> > >
> > > tme> SSM also has source scoping, 239/8 can be used with either SSM or ASM. Therefore
> > > tme> s/If the ASM model is used, this/For IPv4 multicasts, this/
> >
> > I rephrased as follows:
> >
> > "For IPv4 multicast, this implies the use of the multicast
> > administratively scoped range, (239/8 as defined by [RFC2365]) for
> > services which are to be used only inside the VPN, and of or SSM-range
> 
> s/of or SSM-range/of either global SSM-range/
> 
> to correct a typo and to make it clear that 232 is intended for global
> scope SSM.

Agreed.

> > >    Unwanted multicast traffic (e.g. multicast traffic that may be sent
> > >    by a source located somewhere in the Internet and for which there is
> > >    no interested receiver connected to a given VPN infrastructure) MUST
> > >    NOT be propagated within a multicast-enabled VPN.
> > >
> > > tme> Is this consistent with Section 5.2.2.3. ? It seems to me that this
> > > tme> should be a SHOULD NOT to allow for sub-optimal solutions
> >
> >
> > While it might be acceptable (for provider-side scalability) that some
> > traffic reaches a PE even if this is not needed, it would not be
> > acceptable that such traffic be propagated toward the CE, inside the
> > customer network.
> >
> > Isn't this reasonable ?
> 
> Reasonable, but in normal multicast it is common to get multiple
> packets when trees switch over.

A bit of misunderstanding here: we are just mandating that, in the same
way that traffic from a VPN doesn't reach another VPN, Internet
multicast traffic won't be routed inside a VPN that didn't make any such
multicast subscription.

In normal multicast, you are not supposed to route @G traffic to
somebody who only subscribed to @G' and @G'', right ?

-Thomas