Subject: [Last-Call] Intdir telechat review of draft-ietf-dmm-pmipv6-dlif -05

From: "Carlos Pignataro (cpignata)" <[email-masked]>
Date: Sat, 29 Feb 2020 03:15:40 +0000

Reviewer: Carlos Pignataro
Review result: Ready with Nits

I am an assigned INT directorate reviewer for this Internet-Draft.  These
comments were written primarily for the benefit of the Internet Area Directors.
Document editors and shepherd(s) should treat these comments just like they
would treat comments from any other IETF contributors and resolve them along
with any other Last Call comments that have been received. For more details on
the INT Directorate, see http://www.ietf.org/iesg/directorate.html.

I hope these comments are clear and useful.

As requested, from the Internet area Directorate review, these two DMM 
documents are being reviewed together: 
* draft-ietf-dmm-distributed-mobility-anchoring-14
* draft-ietf-dmm-pmipv6-dlif-05

This document defines distributed mobility anchoring, in terms of the 
different configurations and functions to provide IP mobility support, 
including network-based or host-based mobility support.

The intended status is Informational. It is a very well written and comprehensive
document. It is technically sound.

No major or minor issues.

Nits:

A set of small nits for your consideration.

1.  Introduction

   As a Mobile Node (MN) attaches to an access router and establishes a
   link between them, a /64 IPv6 prefix anchored to the router may be
   assigned to the link for exclusive use by the MN [RFC6459].  The MN
   may then configure a global IPv6 address from this prefix and use it
   as the source IP address in a flow to communicate with its
   correspondent node (CN).

Capitalize:
s/correspondent node/Correspondent Node/

2.  Conventions and Terminology

   These include terms such as mobile node (MN), correspondent node
   (CN), home agent (HA), home address (HoA), care-of-address (CoA),
   local mobility anchor (LMA), and mobile access gateway (MAG).

Capitalize “Mobile Node” (as per § 1), “Corespondent Node”, etc.

Similar within this same § 2, “mobile router”, etc.
Same throughout the document (e.g., “router advertisement (RA)”)

4.3.  Mobility case, anchor relocation

   The IP prefix/address anchoring may move without changing the IP
   prefix/address of the flow.  Here the LM and FM functions in Figure 1
   in Section 3.1 are implemented as shown in Figure 7.

“Figure 1 in Section 3.1.1 are implemented”

                         Figure 7: Anchor mobility

Should this figure’s label be “Anchor Relocation” instead of ‘Anchor mobility”?

5.  Security Considerations

   As stated in [RFC7333], "a DMM solution MUST supportany security

s/supportany/support any/

8.2. Informative References

The relationship of this document and draft-ietf-dmm-deployment-models is mostly clear, thank you for that.

I hope you fid these comments useful.

Carlos Pignataro.

https://tools.ietf.org/html/draft-ietf-dmm-pmipv6-dlif-05

I am an assigned INT directorate reviewer for this Internet-Draft.  These
comments were written primarily for the benefit of the Internet Area Directors.
Document editors and shepherd(s) should treat these comments just like they
would treat comments from any other IETF contributors and resolve them along
with any other Last Call comments that have been received. For more details on
the INT Directorate, see http://www.ietf.org/iesg/directorate.html.

I hope these comments are clear and useful.

As requested, from the Internet area Directorate review, these two DMM 
documents are being reviewed together: 
* draft-ietf-dmm-distributed-mobility-anchoring-14
* draft-ietf-dmm-pmipv6-dlif-05

This document provides an approach to distributed mobility management
by extending network-based mobility protocols (like Proxy Mobile IPv6). In
this solution, mobility sessions are anchored at the last IP hop router. 

This document’s intended status is Experimental. It is well written for such a complex comprehensive document, and technically complete and sensible.

No major or minor issues.

Nits:

Please find some small comments for your consideration:

4.1.  Proxy Binding Update

   A new flag (D) is included in the Proxy Binding Update to indicate
   that the Proxy Binding Update is coming from a Mobility Anchor and
   Access Router and not from a mobile access gateway.  The rest of the
   Proxy Binding Update format remains the same as defined in [RFC5213].

   0               1               2               3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
                                   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                   |            Sequence #         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |A|H|L|K|M|R|P|F|T|B|S|D| Reser |            Lifetime           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

However, for RFC 5213 S 8.1:

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |A|H|L|K|M|R|P|  Reserved       |            Lifetime           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

So, therefore, seems like:
1. The definition of Flags F, T, B, and S is missing.
2. “Reser” is not really clear and “Rsrvd” seems to fit and be more unambiguous.

4.2.  Proxy Binding Acknowledgment

…
  The rest of the Proxy Binding Acknowledgment format
   remains the same as defined in [RFC5213].

   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
                                   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                   |   Status      |K|R|P|T|B|S|D| |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

However, from RFC 5213:

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
                                      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                      |   Status      |K|R|P|Reserved |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

And thus, Flags T, B, S are not defined.

4.3.  Anchored Prefix Option

   Anchored Prefix

      A sixteen-byte field containing the mobile node's IPv6 Anchored
      Prefix.  Only the first Prefix Length bytes are valid for the
      Anchored Prefix.  The rest of the bytes MUST be ignored.

Not being pedantic, but:
s/byte/octet/g // throughout.
Or… "128-bit” instead of “sixteen-octet”.

5.  IANA Considerations

   This document defines six new mobility options that need to be
   registered in the Mobility Options registry on the Mobile IPv6
   parameters registry.  The required IANA actions are marked as IANA-1
   to IANA-6.

It would be useful to breakout the specific IANA requests in a table, sections, or other structure detailing how it should look in the IANA registries.

6. Security Considerations

Is there underlying protection against spoofing that can be called out? This should be addressed in the Security Dir review, so I will not mention it here 🙂

8.2.  Informative References

   [I-D.ietf-dmm-deployment-models]
              Gundavelli, S. and S. Jeon, "DMM Deployment Models and
              Architectural Considerations", draft-ietf-dmm-deployment-
              models-04 (work in progress), May 2018.

Since there are key definitions from this document, should this be Normative?

   [RFC7333]  Chan, H., Ed., Liu, D., Seite, P., Yokota, H., and J.
              Korhonen, "Requirements for Distributed Mobility
              Management", RFC 7333, DOI 10.17487/RFC7333, August 2014,
              <https://www.rfc-editor.org/info/rfc7333>.

Similarly, should this reference be Normative instead of Informative?

Appendix B.  Implementation experience

Should this really be an Implementation Status section [RFC7942], as it describes a point in time rather than learnings?

Should the Appendices clarify they make no normative specs?

I hope these comments are useful.

Thank you very much,

Carlos Pignataro.