Telechat Review of draft-ietf-manet-dlep-25
review-ietf-manet-dlep-25-tsvart-telechat-scharf-2016-12-14-00

Hi,

I've reviewed this document as part of TSV-ART's ongoing effort to review key
IETF documents. These comments were written primarily for the transport area
directors, but are copied to the document's authors for their information and
to allow them to address any issues raised. When done at the time of IETF Last
Call, the authors should consider this review together with any other last-call
comments they receive. Please always CC tsv-art@ietf.org if you reply to or
forward this review.

This draft is basically ready for publication, but has nits that should be
fixed before publication.

TSV-ART review comments:

* I think the DLEP protocol makes an implicit assumption that the 1-hop link
between the router and the modem is unlikely to become a bottleneck, e.g.,
because its bandwidth is larger than the maximum possible bandwidth of the
modem. I assume that in typical deployments this condition can be fulfilled,
and the hop count limitation provides some safety measures. Yet, the link
between the router and modem could possibly run over a tunnel, with unknown
performance characteristics (e.g., another wireless backhaul link). It is
unclear what a router would indeed learn from the information provided by DLEP
in such a case. This scenario is not the target environment for the protocol,
but it would make sense to more explicitly spell out that assumption, e.g., in
Section 1.

Other comments:

* Page 9: "If the router and modem support both IPv4 and IPv6, the IPv6
transport MUST be used for the DLEP session." seems inconsistent with page 21:
"For routers supporting both IPv4 and IPv6 DLEP operation, it is RECOMMENDED
that IPv6 be selected as the transport."

* I am not an IANA expert but at first sight the IANA section does not
comprehensively describe the policy for modifying the IANA registries (Section
4 in RFC 5226). Is it "Standards Action"? This in particular matters for the
extensions in Section 13.6.

Thanks

Michael