Hi Jonathan, I support your comments completely here. Adding TCP compression in another draft would give us lots of time to design & test it, as the TCP compression will be more complex than UDP.
I think almost any node will need to support UDP as a matter of normal operation. But not all nodes will support TCP, many may just use UDP. Hence it makes sense for that reason to keep TCP out of the HC. In addition I would like to see the issue of MUSTs worked out. The current I-D doesn't explicitly specify what features / addressing modes you must support. Having this document moving towards RFC status would be a great boost to implementers & 6LoWPAN. Then you can simply say you support "RFC4944 + RFCDEADBEEF", and other people know what frame format you are using. Right now it's "well I support -hc-01" and someone else supports -05, and someone else supports -06 but not all functions. Regards, -Colin -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jonathan Hui Sent: February 25, 2010 7:21 AM To: [email protected] Cc: [email protected]; Reddy, Joseph Subject: Re: [6lowpan] WGLC for 6lowpan HC draft It would be helpful to know what people's expectations are relative to what this specific draft should include relative to an acceptable timeline of getting a document out. Few comments: - The WG currently does not have a proposal for TCP header compression, let alone one that we have built some consensus around. - The RPL protocol mechanisms and headers are still in flux. It is difficult to propose a concrete way of compressing them without knowing what they will look like. For example, within ROLL, we will be proposing ways to "pack" lists of addresses such that common prefixes are only carried once within the datagram. - The general 6lowpan-hc format is generic enough to be used on top of other fragmentation mechanisms and/or frame sizes. Do we really want to limit its capabilities to a particular fragmentation and frame size? There always seems to be a tension between splitting functionality across different drafts vs. delaying the current draft to "sneak" in new functionality. I'm all for sneaking in fixes to RFC 4944 (i.e. simple changes to fragmentation) or additional functionality for expediency if we can realize that expedience. But waiting until we design a TCP header compression mechanism that we can build consensus around probably isn't the best approach, in my opinion, and should be left to a separate draft. So what do others think? (I will start a new thread specifically on fragmentation + forward- compatibility so that we drive towards closure on that specific issue). -- Jonathan Hui On Feb 24, 2010, at 10:55 PM, Robert Cragie wrote: > Hi Geoff, > > I concur with Joseph's statements and thus do not support forwarding > the draft to IESG yet. > > Robert > Robert Cragie (Pacific Gas & Electric) > > Gridmerge Ltd. > 89 Greenfield Crescent, > Wakefield, WF4 4WA, UK > +44 (0) 1924 910888 > http://www.gridmerge.com > > > > Reddy, Joseph wrote: >> >> >> Hi Geoff, >> >> I do not support forwarding this doc to IESG yet. I would like the >> following issues addressed >> >> ** Investigate possible TCP header compression scheme >> >> ** Explain strategy for compressing RPL headers ( I understand this >> could be done in the ROLL group, but I have not seen a definite >> statement either way ) >> >> ** Resolve the "forward compatability" issue ( ideally, while >> maintaining backwards-comptability ) >> >> >> -Regards, Joseph >> >> >> >> ---------------------------------------------------------------------- >> >> Message: 1 >> Date: Sat, 13 Feb 2010 00:56:31 -0700 >> From: Geoff Mulligan <[email protected]> >> Subject: [6lowpan] WGLC for 6lowpan HC draft >> To: 6lowpan <[email protected]> >> Message-ID: <1266047791.3643.48.ca...@dellx1> >> Content-Type: text/plain >> >> Folks, >> I realized that I have made a huge slip-up. The HC draft has >> languished for the past few months. >> At the meeting in Hiroshima we said that we would last call this >> draft, but I failed to send out the actual last call. So... >> >> This note formally starts the WG Last Call for comments on draft- >> ietf-6lowpan-hc-06, "Compression Format for IPv6 Datagrams in >> 6LoWPAN Networks". >> >> The document can be found at: >> http://www.ietf.org/id/draft-ietf-6lowpan-hc-06.txt >> >> The document is intended to be submitted by this Working Group to >> the IESG for publication as a Standards Track document. >> >> Please review the document carefully (one last time), and send your >> comments to the 6lowpan list. Please also indicate in your >> response whether or not you think this document is ready to go to >> the IESG. >> >> Because of my gaffe this Last Call will end Wednesday February 24 >> 2010 at 2359 UTC. >> >> Thanks, >> Geoff >> >> >> >> >> >> ************************************** >> _______________________________________________ >> 6lowpan mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/6lowpan >> >> > _______________________________________________ > 6lowpan mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/6lowpan _______________________________________________ 6lowpan mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lowpan _______________________________________________ 6lowpan mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lowpan
