Transmission of IPv6 via the IPv6 Convergence Sublayer over IEEE 802.16 Networks
RFC 5121

Approval announcement
Draft of message to be sent after approval:

From: The IESG <iesg-secretary@ietf.org>
To: IETF-Announce <ietf-announce@ietf.org>
Cc: Internet Architecture Board <iab@iab.org>,
    RFC Editor <rfc-editor@rfc-editor.org>, 
    16ng mailing list <16ng@ietf.org>, 
    16ng chair <16ng-chairs@tools.ietf.org>
Subject: Protocol Action: 'Transmission of IPv6 via the IPv6 CS 
         over IEEE 802.16 Networks' to Proposed Standard 

The IESG has approved the following document:

- 'Transmission of IPv6 via the IPv6 CS over IEEE 802.16 Networks '
   <draft-ietf-16ng-ipv6-over-ipv6cs-12.txt> as a Proposed Standard

This document is the product of the IP over IEEE 802.16 Networks Working 
Group. 

The IESG contact persons are Jari Arkko and Mark Townsley.

A URL of this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-16ng-ipv6-over-ipv6cs-12.txt

Technical Summary

  This document specifies the addressing and operation of IPv6 over
  the IPv6 specific part of the packet CS for hosts served by a
  network that utilizes the IEEE Std 802.16 air interface. It
  recommends the assignment of a unique prefix (or prefixes) to each
  host and allows the host to use multiple identifiers within that
  prefix, including support for randomly generated identifiers.

Working Group Summary

  There was much initial debate about the link model to adopt.
  The interim made it clear that the "per-MS" prefix was
  preferable. Beyond that, there has been debate about how much
  802.16-specific details to include (e.g., on network entry
  procedure) for clarity.

Document Quality

  There are no currently known implementations of this document.
  However, the per-MS prefix model has been deployed in 3GPP, so
  at least that part is known to work, and this was a major point
  in deciding in its favor. The WiMax forum sees this document as one
  of its pilars, so it is expected that it will see significant
  deployment within the next years.

  This specification was reviewed by Jari Arkko for the IESG
  and by Pekka Savola and Margaret Wasserman for the IP Directorate
  in the Internet Area.

  Members of the IEEE 802.16 group were asked for review, and
  a number of reviews were received during IETF Last Call period.

Personnel

  Shepherd: Gabriel Montenegro
  AD: Jari Arkko

Note to RFC Editor
  
  Please change in Section 8.1:

  OLD:
    The use of router advertisements as a means for movement detection is
    not recommended for MNs connected via 802.16 links as the frequency
    of periodic router advertisements can be high.
  NEW:
    The use of router advertisements as a means for movement detection is
    not recommended for MNs connected via 802.16 links as the frequency
    of periodic router advertisements would have to be high.

  Please add new text at the end of Section 4 (just before 4.1),
  these are the new paragraphs:

    In any case, the MS and BS MUST negotiate at most one
    convergence sublayer for IPv6 transport on a given link.

    In addition, to ensure interoperability between devices that
    support different encapsulations, it is REQUIRED that BS
    implementations support all standards track encapsulations
    defined for 802.16 by the IETF. At the time of writing this
    specification, this is the only encapsulation, but additional
    specifications are being worked on. It is, however, not
    required that the BS implementations use all the encapsulations
    they support; some modes of operation may be off by
    configuration.

  Change in Appendix D:

  OLD:
    It is
    recommended that the default MTU for IPv6 be set to 1400 octets for
    the MS in WiMAX networks.  
  NEW:
    It is recommended that the MTU for IPv6 be set to 1400 octets in
    WiMAX networks, and this value (different from the default)
    be communicated to the MS.

  Change Section 6.3 to:

   The MTU value for IPv6 packets on an 802.16 link is configurable.
   The default MTU for IPv6 packets over an 802.16 link SHOULD be 1500
   octets.

   The 802.16 MAC PDU (Protocol Data Unit) is composed of a 6 byte
   header followed by an optional payload and an optional CRC covering
   the header and the payload.  The length of the PDU is indicated by
   the Len parameter in the Generic MAC Header.  The Len parameter has a
   size of 11 bits.  Hence the total MAC PDU size is 2048 bytes.  The
   IPv6 payload size can vary.  In certain deployment scenarios the MTU
   value can be greater than the default.  Neighbor Discovery for IPv6
   [RFC4861] defines an MTU option that an AR MUST advertise, via router
   advertisement (RA) if a value different from 1500 is used.
   The MN processes this option as defined in [RFC4861].
   Nodes that implement Path MTU discovery [RFC1981] MAY use the
   mechanism to determine the MTU for the IPv6 packets.

  In the abstract: 
    s/fxed/fixed/
 
  In section 6.1:
    s/it is recommended that a tunnel is established/it is recommended
    that a tunnel be established/