Subject: [mpls] Comments to draft-nadeau-pwe3-vccv-2-01

From: Greg Mirsky <[email-masked]>
Date: Fri, 11 Mar 2011 14:26:35 -0800

Dear Authors,
please find my comments below.

   - this proposal is closely related to changes to RFC 5586 put forward in
   draft-lm-pwe3-mpls-tp-gal-in-pw-00 but there's no reference to the draft.
   - RFC 5586 states and the draft-lm-pwe3-mpls-tp-gal-in-pw-00 maintains
   that in MPLS-TP network the GAL must be BoS. Only in non-TP MPLS netowrks
   GAL might be not a BoS. In your proposal the GAL precedes the PW and thus is
   not BoS. But the document's scope is for all MPLS PWs, including over
   MPLS-TP PSN. Unless statement in Section 4.2 RFC 5586 "In MPLS-TP (GAL) ...
   MUST always be at the bottom of the label stack (i.e., S bit set to 1)"
   updated proposed use of GAL is allowed only in non-TP MPLS PSN.
   - Section 2 lists of allowed ACH. Since these are hexadecimal numbers I'd
   suggest prepending them with '0x' to make as "0x07, 0x21, and 0x57". And I'd
   ask for clarification of "allowed". Is it "MAY", "SHOULD" or "MUST" be
   limited to ... A, B, C"?
   - In Section 3 stated that TTL in PW LSE must be set to 1 for SS-PW and
   to appropriate value in MS-PW to reach intended PE. Hence my question, Is
   this mechanism to reach MIP, i.e. S-PE, or this is mechanism to generate
   exception? But that is how PW VCCV Control Channel Type 3 works. What is the
   interpretation of GAL in a label stack? To indicate PW CW after the PW LSE?
   - editorial - in Abstract s/The MPLS/the MPLS or a reference to, perhaps,
   RFC 5654.

Regards,
Greg