Subject: [bess] Comment on draft-ietf-l3vpn-mvpn-extranet-01

From: Rishabh Parekh <[email-masked]>
Date: Tue, 16 Jun 2015 13:14:41 -0700

WG,

This draft was revised earlier to make clear that the ambiguity
described in Section 2.1 applies only to customer SSM groups. However,
one of the preventive policies (Section 2.3.2) to avoid this
ambiguity, "Single C-group per (C-*,C-G) P-tunnel" policy, was carried
forward from an earlier revision where the ambiguity applied to
customer ASM groups too.

Now that both ambiguities are only applicable for customer SSM groups,
I don't think that "Single C-group per (C-*,C-G) P-tunnel" policy is
required. First, RFC 6625 (Section 4.2) recommends that (C-*,C-G)
S-PMSIs should be used only for customer ASM groups. Second, even if
(C-*,C-G) S-PMSIs are used for customer SSM groups, I don't see how
the policy can address ambiguity of Section 2.1 because it would allow
an intranet SSM channel, say (S1,G), and an extranet SSM channel, say
(S2,G), to be transmitted on the same P-tunnel, leading to the
ambiguity.

Any thoughts?
-Rishabh