(moving discussion to LWIG list) > On 13 Jun 2016, at 12:57, Carles Gomez Montenegro <carle...@entel.upc.edu> > wrote: > >> 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. > > I understand that what you point out may happen in many cases... However, > a device, in some cases, might want to send e.g. two (or more) packets > back to back to the same destination. In those, the window size of one > would make a difference. > > By the way, currently the phrasing in the draft is that a window size of > one 'MUST' be used. This keeps a behavior equivalent to that of CoAP for > confirmable messages in RFC 7252, and dramatically simplifies > implementations. However, I wonder if some more freedom should be offered, > and maybe the 'MUST' could become a 'SHOULD', at the expense of opening > the door to greater complexity... I personally tend to prefer the first > approach, but it would be great to receive more feedback on this!
I like the simplicity too and would envision using that in cases where I'm using TCP for middlebox traversal cases. On the other hand, when doing something like firmware update for not-that-constrained device over long RTT link, this restriction could bite back big time. That makes me wonder if it would make sense to be able to indicate the capability for doing window bigger than 1 e.g., in RD registration. Cheers, Ari _______________________________________________ Lwip mailing list Lwip@ietf.org https://www.ietf.org/mailman/listinfo/lwip
