On 12/9/2016 1:38 PM, Michael Tuexen wrote: >> On 9 Dec 2016, at 22:30, Joe Touch <to...@isi.edu> wrote: >> >> >> >> On 12/9/2016 1:26 PM, Michael Tuexen wrote: >>> Not sure what the reassembly limit is... SCTP handled arbitrary sized >>> user messages a the receiver side by using partial delivery. >>> >>> The SCTP_MAXSEG allows a user to limit the size of DATA chunks without >>> reducing the pmtu. >> Yes, but that size can actually be larger than the PMTU, not just smaller. > Hmm. https://tools.ietf.org/html/rfc6458#section-8.1.16 states: > > Note that the > underlying SCTP implementation may fragment into smaller sized chunks > when the PMTU of the underlying association is smaller than the value > set by the user. > > So this means the user can not rely on this option to turn off SCTP > fragmentation and let SCTP pass IP-packets down the stack to let > the IP do the fragmentation. > > That is why I said, the user can use this option to ask the SCTP > layer to use a smaller value than the one deduced from the PMTU. > That is something you can do safely.
It seems like this setting is independent of PMTU. It could be larger than PMTU, in which case SCTP *or* IP could do fragmentation (and I don't see whether there's a way to know or force that decision). Yes, you can set it smaller too. Joe _______________________________________________ Taps mailing list Taps@ietf.org https://www.ietf.org/mailman/listinfo/taps
