Subject: [Gen-art] Gen-art LC review of draft-ietf-mpls-mldp-in-band-wildcard-encoding-02

From: Elwyn Davies <[email-masked]>
Date: Fri, 31 Oct 2014 19:47:19 +0000

I am the assigned Gen-ART reviewer for this draft. For background on
Gen-ART, please see the FAQ at

<http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.

Please resolve these comments along with any other Last Call comments
you may receive.

Document: draft-ietf-mpls-mldp-in-band-wildcard-encoding-02.txt
Reviewer: Elwyn Davies
Review Date:  2014-10-31
IETF LC End Date: 2014-10-27
IESG Telechat date: (if known) -

Summary:
Almost ready.  There are a couple of clarifications around how IPv4 and 
IPv6 trees can or cannot be merged on a single MP-LSP that would be 
advantageous.  Also the error handling in the parent RFCs
(6388, 6826) is a bit sketchy resulting in messy handling if an LSR that 
does not support the wildcard
encoding is accidentally sent the TLVs from this draft.  I am not sure 
if this can be cleaned up (and maybe there is no thought to be a problem 
- I am not sufficiently expert in LDP signalling).

PS Apologies for the late review - Overtaken by holidays.

Major issues:
None.

Minor issues:
IPv4 and IPv6 Multicast: I think it would be useful to add a short 
discussion of the fact that there are both IPv4 and IPv6 multicast 
trees.  Presumably an MP-LSP can only carry one or the other at a time, 
but I am unclear about whether this is the case. Also a note in s3.1 
that it is either the IPv4 or IPv6 address fields that are relevant and 
they are all zeroes in either case would clarify the usage further.

RFC 5918 Typed Wildcard:  Is there anything special that has to be done 
if the Typed Wildcard is used?

s3.3:  Is it possible to specify the error behaviour more concretely 
(i.e., what might  happen) in case an unadapted Ingress LSR gets a 
wildcard TLV?  It appears that RFC 6826 is rather underspecified as 
regards error handling - but I am not an expert on this area - it 
appears that the MP-LSP would get set up but to no good purpose which 
seems inappropriate.  Could an error status not be returned?

Nits/editorial comments:
s2, Definition of 'in-band signalling': Should also allow for (S,*) - 
and possibly (*,*), I believe.

s3.4: s/PIM ASM/PIM-ASM/