Re: [16NG] [nwg-chair] NWG feedback on 16ng's IPv4 CS draft

Hi Wes,

Yes, there will be an updated draft before Stockholm. Gabriel was working on
the updates.

I am expecting that we will soon have a revision to review.

Thanks,
-Samita

> -----Original Message-----
> From: 16ng-bounces at ietf.org [mailto:16ng-bounces at ietf.org] On Behalf Of
> Wesley George
> Sent: Friday, May 15, 2009 9:54 AM
> To: Riegel, Maximilian (NSN - DE/Munich)
> Cc: ext Alper Yegin; ext Gabriel Montenegro; 16ng at ietf.org
> Subject: Re: [16NG] [nwg-chair] NWG feedback on 16ng's IPv4 CS draft
>
> Is someone working on an updated version of this draft to be reviewed in
> Stockholm since we did not meet in SFO? I believe that one of the first
> times that I submitted objections to the MTU language, I provided a
proposed
> text that would cover some of the concerns raised below, not all of which
> was included in subsequent drafts.
> http://www.ietf.org/mail-archive/web/16ng/current/msg00824.html
>
> Thanks,
> Wes
>
> _________________________________________
>    Wesley George
>        Sprint IP Engineering
>    703-689-7505 (O) 703-864-4902 (PCS)
>          http://www.sprint.net
> _________________________________________
>
>
> On Thu, 12 Feb 2009, Riegel, Maximilian (NSN - DE/Munich) wrote:
>
> > Gabriel,
> >
> > The WiMAX Forum NWG reviewed section 4-3 and Appendix C of
> > draft-ietf-16ng-ipv4-over-802-dot-16-ipcs-04.txt and would like to
> > make a couple of remarks on the MTU issue:
> >
> > - The I-D is not very clear about the MTU issues appearing in an IPv4
> > over IEEE 802.16 transmission system. The ambiguities mainly result
> > out of the vague definition of the IEEE 802.16 link comprising both
> > the radio part of the link as well as the part of the link between BS
> > and AR, when the functions are located in different entities.
> >
> > - Section 4.3 in particular misses the discussion of the dependencies
> > between MTU size and the tunneling protocol deployed between BS and AR.
> >
> > - Section 4.3 also misses, that there is no packet loss when the MTU
> > size limitation is caused by the encapsulation overhead on the link
> > between BS and AR. E.g. when GRE is used for the tunnel between BS and
> > AR, the transport IP layer can fragment the GRE packets to fit the
> > transport MTU on the link between BS and AR. Reassembly in the tunnel
> > endpoint at the AR will re-establish the original user IP packet.
> >
> > - Please note that the reason of the WiMAX NWG to limit the MTU going
> > over IPv4-CS to 1400 Bytes was to avoid fragmentation on the link
> > between BS and ASN-GW as well as on the link between ASN-GW and CSN
> > (MIP tunnel). Fragmentation and re-assembly require considerable
> > processing power in the network elements.
> >
> > - Appendix C makes statements which would require more detailed review
> > of the I-D by WiMAX NWG. In particular 'The addressing and operation
> > of IPv4-CS described in this document are applicable to the WiMAX
> > networks as well' has not been verified yet.
> > Furthermore 'Thus, WiMAX MS nodes should use this default (1400) MTU
> > value per the current specification [WMF]. However, due to reasons
> > specified in section 4.3 above, it is strongly recommended that future
> > WiMAX MS nodes support a default MTU of 1500 bytes, and that they
> > implement MTU negotiation capabilities as mentioned in this document.'
> > makes recommendations to WiMAX without understanding the real reasons
> > for the limitation of the MTU size in Mobile WiMAX.
> >
> > We would recommend to 16ng to revise the sections on MTU size to
> > better explain the underlying issues leading to restrictions in the MTU
> size.
> > In particular the influence of tunneling inside the network should be
> > carefully discussed.
> > In addition we would kindly ask to either remove whole Appendix C on
> > the WiMAX MTU size or revise the text explaining the real issues in
> > the WiMAX architecture. In particular the statements on the
> > applicability of the I-D on the WiMAX architecture and the
> > recommendation on future modifications in the WiMAX architecture seem
> > not to be very appropriate to us.
> >
> >
> > Bye
> > Max
> > Vize Chair NWG
> >
> >
> > ________________________________
> >
> > From: ext Gabriel Montenegro [mailto:Gabriel.Montenegro at microsoft.com]
> > Sent: Monday, November 03, 2008 11:59 AM
> > To: nwg-chair at list.wimaxforum.org
> > Cc: 'Daniel Soohong Park'
> > Subject: [nwg-chair] NWG feedback on 16ng's IPv4 CS draft
> >
> >
> >
> > Prakash, Max and Yong Chang,
> >
> >
> > The IETF 16ng WG has published a revision of this draft:
> >
> > "Transmission of IPv4 packets over IEEE 802.16's IP Convergence
> > Sublayer"
> >
> > Per this announcement:
> >
> > http://www.ietf.org/mail-archive/web/16ng/current/msg00863.html
> > <http://www.ietf.org/mail-archive/web/16ng/current/msg00863.html>
> >
> > We understand that this specification currently is not normative to
> > NWG (as opposed to RFC5121 on IPv6 CS). Nevertheless, given its
> > relevance, and with the hope it may become normative to NWG in some
> > future revision, the 16ng WG would like to solicit feedback from NWG
> > on this draft.
> >
> > In particular, please note that this draft specifies a default MTU of
> > 1500, which is different from the WiMAX-specified MTU of 1400 (per
> > the recently approved R1_V1.3.0-Stage-3 NWG specifications). For MTU
> > discussion, please refer to these sections:
> >
> > http://tools.ietf.org/html/draft-ietf-16ng-ipv4-over-802-dot-16-ipcs-0
> > 4#
> > section-4.3
> > <http://tools.ietf.org/html/draft-ietf-16ng-ipv4-over-802-dot-16-ipcs-
> > 04
> > #section-4.3>
> > http://tools.ietf.org/html/draft-ietf-16ng-ipv4-over-802-dot-16-ipcs-0
> > 4#
> > appendix-C
> > <http://tools.ietf.org/html/draft-ietf-16ng-ipv4-over-802-dot-16-ipcs-
> > 04
> > #appendix-C>
> >
> > The 16ng WG will next meet on Nov 18 during the IETF in Minneapolis
> > (https://datatracker.ietf.org/meeting/73/agenda.html). If at all
> > possible, it would be best if comments were received before that date
> > in order for the WG to discuss them during the meeting.
> >
> > Please send your comments to the 16ng at ietf.org <mailto:16ng at ietf.org>
> > mailing list.
> >
> > Thanks,
> >
> > Gabriel and Daniel
> > 16ng co-chairs
> >
> >
> >
> >
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