Hi Carles, Nice draft. I always want to know the complains of TCP problems over Constrained link and device. In the very beginning of Lwig, the IETF79 bof, David Bormann gave an excellent talk about similar issues ( i try to search the IETF proceedings for the talk but failed coz they do not hold it for informative bof ). But we failed to collect these information from implementer or researchers like you further on. Thanks again for this always timely work.
In this respect, I agree with Carsten that your draft being handled in lwig and a talk is welcome at Berlin meeting. Some quick comments for your draft. >3.2. Window Size > A TCP window size of one segment follows the same rationale as the > default setting for NSTART in [RFC7252], leading to equivalent > operation when CoAP is used over TCP. IMHO, it does not matter because if the application has only a short message to send, the de facto effective cwnd will be ONE. >3.3. RTO estimation > challenges of CNNs, in contrast with the RFC 6298 RTO. Therefore, as > per this document, CoCoA RTO SHOULD be used in TCP over CNNs. > Alternatively, implementors MAY choose the RTO estimation algorithm > defined in RFC 6298. One of the two RTO algorithms MUST be > implemented. Is the RTO estimation algorithm link-specific? For example, I knew you have some work on CoCoA over GPRS. Is it always better than the competitor? Cheers, Zhen On Fri, Jun 10, 2016 at 11:10 PM, Carles Gomez Montenegro <[email protected]> wrote: > > Hi Carsten, > > Thanks a lot for your comments. > > While we work to address those, it would be really helpful if folks that > have faced 'bad constrained TCP implementations', and/or have struggled > with middlebox traversal can share their experience. > > Cheers, > > Carles > > > > Carles, > > > > thanks for submitting this. > > > > I think that this draft is truly best handled in LWIG. > > > > We don't *have* to profile TCP for CoAP-over-TCP; people are free to use > > whatever parts of TCP they think are useful. (And, of course, there are > > applications for CoAP-over-TCP that are in the backend.) > > > > On the other hand, it is useful to > > -- manage expectations: > > what can I expect that the *other* side will offer in TCP functionality > > -- give advice to implementers: > > what is useful to implement, what not > > -- collect implementation experience that is relevant for these two > > > > (One interesting effect I'm seeing is that people know how good TCP can > > be, which shapes their expectations, but then they are hurt by using > > really bad constrained TCP implementations... We certainly should be > > paying attention to this on the CoRE WG side.) > > > > My biggest comment is probably that for device-to-cloud, the level of > > TCP functions implemented will be asymmetric (full TCP on cloud side, > > possibly more limited on the device side) -- what is the effect of this > > asymmetry? > > > > Maybe there also needs to be more discussion on the role of the > > middlebox (after all, we are doing CoAP-over-TCP to devices for the sole > > reason to climb over middleboxes). > > > > Grüße, Carsten > > > > > > Scharf, Michael (Nokia - DE) wrote: > >> Heads-up > >> > >> Michael > >> > >> > >> -----Original Message----- > >> From: Lwip [mailto:[email protected]] On Behalf Of Carles Gomez > >> Montenegro > >> Sent: Friday, June 10, 2016 11:36 AM > >> To: [email protected] > >> Cc: [email protected] > >> Subject: [Lwip] [Fwd: New Version Notification for > >> draft-gomez-core-tcp-constrained-node-networks-00.txt] > >> > >> Dear LWIG WG, > >> > >> /** Apologies for possibly multiple similar e-mails... **/ > >> > >> We have just submitted the draft entitled 'TCP over Constrained-Node > >> Networks', which we believe may be of interest to the members of this > >> group. > >> > >> We would like to kindly ask for feedback, specially on the basis of > >> implementation experience. > >> > >> Thank you very much! > >> > >> Kind regards, > >> > >> The authors > >> > >> > >> ---------------------------- Original Message > >> ---------------------------- > >> Subject: New Version Notification for > >> draft-gomez-core-tcp-constrained-node-networks-00.txt > >> From: [email protected] > >> Date: Fri, June 10, 2016 10:38 am > >> To: "Jon Crowcroft" <[email protected]> > >> "Carles Gomez" <[email protected]> > >> -------------------------------------------------------------------------- > >> > >> > >> A new version of I-D, > >> draft-gomez-core-tcp-constrained-node-networks-00.txt > >> has been successfully submitted by Carles Gomez and posted to the IETF > >> repository. > >> > >> Name: draft-gomez-core-tcp-constrained-node-networks > >> Revision: 00 > >> Title: TCP over Constrained-Node Networks > >> Document date: 2016-06-10 > >> Group: Individual Submission > >> Pages: 9 > >> URL: > >> https://www.ietf.org/internet-drafts/draft-gomez-core-tcp-constrained-node-networks-00.txt > >> Status: > >> https://datatracker.ietf.org/doc/draft-gomez-core-tcp-constrained-node-networks/ > >> Htmlized: > >> https://tools.ietf.org/html/draft-gomez-core-tcp-constrained-node-networks-00 > >> > >> > >> Abstract: > >> This document provides a profile for the Transmission Control > >> Protocol (TCP) over Constrained-Node Networks (CNNs). The > >> overarching goal is to offer simple measures to allow for lightweight > >> TCP implementation and suitable operation in such environments. > >> > >> > >> > >> > >> Please note that it may take a couple of minutes from the time of > >> submission until the htmlized version and diff are available at > >> tools.ietf.org. > >> > >> The IETF Secretariat > >> > >> > >> > >> _______________________________________________ > >> Lwip mailing list > >> [email protected] > >> https://www.ietf.org/mailman/listinfo/lwip > >> > >> _______________________________________________ > >> tcpm mailing list > >> [email protected] > >> https://www.ietf.org/mailman/listinfo/tcpm > >> > > > > > _______________________________________________ > Lwip mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/lwip _______________________________________________ Lwip mailing list [email protected] https://www.ietf.org/mailman/listinfo/lwip
