On 6/4/2015 11:15 AM, Pal Martinsen (palmarti) wrote: > >> On 04 Jun 2015, at 17:43, Joe Touch <to...@isi.edu >> <mailto:to...@isi.edu>> 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. Joe _______________________________________________ Taps mailing list Taps@ietf.org https://www.ietf.org/mailman/listinfo/taps
