Lars Eggert said: "A big driver for SCTP was for use a signaling protocol. Other SDOs are using SCTP for signaling in their network architectures, and are also now introducing NAT functionality at controlled places in these architectures. This is why I believe and have argued that an IETF BCP that documents how to correctly NAT SCTP is the right thing to produce. (And, FWIW, DCCP. There's some interest in that as well, but not such an immediate one as for SCTP.) As a SIP-area person, this mode of operation should be familiar to you. Will this BCP make SCTP available behind a home NAT? Nope. But it provides a specification that people can refer to who design network architectures that are more tightly controlled than the end user Internet, i.e., where people can define and then require their NATs to have this functionality." I agree with Lars here -- having a specification is the first step. However, I would suspect that clearly specifying how SCTP and DCCP work with NAT would eventually make it possible to obtain a home NAT supporting those protocols, particularly if implementations were made available within the popular distributions (e.g. DD-WRT) on which those home NATs are frequently based. On another note, I think it makes a difference whether UDP/TCP is combined with IP at the waist, or whether UDP/TCP is considered a lower layer on which IP, etc. can run. That is, whether we have general NAT traversal mechanisms which support a wide array of applications, or whether we end up having to modify each individual protocol. The draft seems to suggest the latter approach. I disagree. _______________________________________________ Ietf@xxxxxxxx http://www.ietf.org/mailman/listinfo/ietf