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/