> On 04 Jun 2015, at 20:27, Joe Touch <[email protected]> wrote: > > > > On 6/4/2015 11:15 AM, Pal Martinsen (palmarti) wrote: >> >>> On 04 Jun 2015, at 17:43, Joe Touch <[email protected] >>> <mailto:[email protected]>> wrote: >>> >>> >>> >>> On 6/4/2015 3:48 AM, Pal Martinsen (palmarti) wrote: >>> ... >>>> Does it make sense for the TAPS transports draft to add ICMP? >>> >>> ICMP is not a transport protocol. >> >> Sure. And I agree. But it has the potential to influence how the various >> transport protocols behave. That interaction might be nice to have >> described in the transports draft. > > Abstract APIs need to be described. These are part of that description. > >>> The ways in which transport protocols either terminate or pass-through >>> ICMP messages is part of the transport protocol abstract API. >>> >>> E.g., for UDP and TCP see RFC1122. >>> >>> UDP passes all ICMP messages to the app. >>> >> No. Not unless the application specifically listens for it. > > UDP passes all ICMP messages to the app. If the app doesn't listen for > it, that's the app's decision. > >> Unfortunately how to do this varies from OS to OS: >> See >> https://tools.ietf.org/html/draft-martinsen-tram-stuntrace-01#appendix-A.2 >> for >> examples. > > You are confusing the OS and language-dependent implementation of the > API with the abstract API. > > RFC1122 requires that UDP implementations make the ICMP signals > available to the application. It does not indicate by what mechanism. > >> Listening for port unreachable can be nice to avoid spamming a host or >> application that recently crashed. Detecting fragmentation or max MTU is >> also a nice feature especially VoIP applications sending video can >> utilise to optimise their packet sizes. > > UDP is required to pass ALL ICMP messages to the app layer, as per RFC 1122. > >>> TCP passes only dest unreachable types 0, 1, and 5, time exceeded and >>> parameter problem. All others it interprets or ignores internally and >>> it’s not clear it should pass up to the app. >> >> That is exactly that kind of information I would find useful in the >> transports draft. > > Well, yes - IMO, that's because it's part of the abstract API. > >> Any pitfalls with ICMP when doing SCTP? > > In many ways, SCTP subsumes similar requirements as TCP, but that's > probably buried in the SCTP docs. It is. See https://tools.ietf.org/html/rfc4960#appendix-C
Best regards Michael > > Joe > > _______________________________________________ > Taps mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/taps _______________________________________________ Taps mailing list [email protected] https://www.ietf.org/mailman/listinfo/taps
