[mpls] Comments on draft-ietf-ccamp-mpls-tp-cp-framework-02

["Eric Osborne (eosborne)" <[e-mail]>]

I have a few questions.  Nothing major, as the draft is in general
pretty solid.



1) Section 4.1 reviews existing GMPLS functionality and describes
applicability to TP.  Section 4.1.8 defines LSP hierarchy but doesn't
say anything about how it applies to TP.  It probably needs a line like
"Hierarchical LSPs may be used in MPLS-TP at the discretion of the
network operator" or something similar ot what's in other subsections of
4.1.


2) Some of section 4.1.9 is out of sync with the surviveability
framework (draft-ietf-mpls-tp-survive-fwk)

 - survive-fwk draws a distinction between protection and restoration
that  cp-framework lumps under 'recovery'.  It may be worth calling out
both protection and restoration as separate things.

- Section 4.1.9 lists five recovery types:

     - 1+1 bidirectional protection for P2P LSPs
     - 1+1 unidirectional protection for P2MP LSPs
     - 1:n (including 1:1) protection with or without extra traffic
     - Rerouting without extra traffic (sometimes known as soft
       rerouting), including shared mesh restoration
     - Full LSP rerouting


I don't see where these five types come from.  rfc5654 requirements R65
and R67 list five MUST types (bidir 1+1 p2p, unidir 1+1 p2p, unidir 1+1
p2mp, bidir 1:n p2p, unidir 1:n p2mp) and one optional (undir 1:n p2p).
R68 requires 1:n (including 1:1) ahread mesh recovery.  

How do the five types in section 4.1. 9 map to the requirements in
rfc5654?  At first glance I don't see unidir 1+1 p2p in sec. 4.1.9,
although perhaps it's implied in 'rerouting without extra traffic'.
'Full LSP rerouting' also seems like it may mean something specific to
whomever wrote it but as far as I can tell there's no explicit
definition of 'Full LSP rerouting' (as opposed to partial?  as opposed
to something other than rerouting?) anywhere in rfc5654 or survive-fwk.
And 'soft rerouting appears to be survive-fwk's 'soft restoration'.

3) Section 4.1.9, "it's use is not precluded" , s/it's/its/


4) Section 4.4.1 is entitled "MPLS to MPLS-TP Interworking".  The
section talks about " interworking of MPLS-TE and GMPLS control plane",
so shouldn't the section be "MPLS-TE to MPLS-TP Interworking"?  Unless
things like LDP-to-TP interworking are in someone's plans, I think "TE
to TP Interworking" is a better fit.







eric