Re: AW: 232-Addresses not only for current SSM model

[Toerless Eckert <eckert@cisco.com>]

On Wed, May 02, 2001 at 10:24:17PM +0200, Doron Rajwan wrote:
> 
> I think that Heinrich means that 232/8 is reserved for SSM service model
> in general, but not for PIM-SSM specific protocol.
> 
> Is this the case?  Does it matter?

Yes, no, not practially, maybe theoretically.

The SSM architecture mandates that SSM is based on a receiver driven channel
subscription mechanism, which translates into an explicit join model within
the network. What protocol you want to use within some parts of the path
is really insignificant. For example, you could imagine that some path segments
may use IGMP (proxying/mapping from/to PIM or other protocols) for whatever
obscure reasons they might choose to do that.

The only issue really is that if you start out with some other protocol and
can not map from/to PIM path segments, you'll start out having two islands,
which would mean one had to make the decision which of the two islands would
have to be called the real global 232/8 address space and which would just
be a private reuse of global addresses outside of the scope of the IETF/IANA.
So better avoid that situation if the goal here is to establish a framework
for easy scalable global reachability of ip multicast delievered content.

Cheers
	Toerless