Re: draft-ietf-mpls-rsvp-te-p2mp-06.txt [P2MP ID]

[Yakov Rekhter <yakov@juniper.net>]

Lou,

[since the answer to the question you posed below may benefit
other folks, I added mpls and ccamp mailing list to the cc:]

> Rahul,
>          Okay, so I'm just a bit slow.  Can you explain why the 
> semantics of P2MP-TE needs to be different than P2P-TE?
> 
> Yakov,
> 
> Perhaps you should answer this?
>
> Lou

To answer your question observe that in P2P-TE the Session object
carries IPv4 tunnel end point address, while in P2MP-TE the Session
object carried P2MP-ID.

Here are some of the reason(s) semantics of IPv4 tunnel end point
address needs to be different than P2MP-ID:

1. IPv4 tunnel end point address is a unicast address. P2MP-ID
is not. 

2. IPv4 tunnel end point address is suitable for hierarchical routing
(e.g., CIDR). P2MP-ID is not.

3. There are well-established procedures for assigining (globally)
unique unicast IP addresses. There are no such procedures for
assigining (globally) unique P2MP IDs.

Yakov.