On Wed, Sep 30, 2020 at 12:40 AM Michael Tuexen <tuexen@xxxxxxxxxxxxxx> wrote: > > > On 29. Sep 2020, at 15:48, Xin Long <lucien.xin@xxxxxxxxx> wrote: > > > > Description From the RFC: > > > > The Main Reasons: > > > > o To allow SCTP traffic to pass through legacy NATs, which do not > > provide native SCTP support as specified in [BEHAVE] and > > [NATSUPP]. > > > > o To allow SCTP to be implemented on hosts that do not provide > > direct access to the IP layer. In particular, applications can > > use their own SCTP implementation if the operating system does not > > provide one. > > > > Implementation Notes: > > > > UDP-encapsulated SCTP is normally communicated between SCTP stacks > > using the IANA-assigned UDP port number 9899 (sctp-tunneling) on both > > ends. There are circumstances where other ports may be used on > > either end, and it might be required to use ports other than the > > registered port. > > > > Each SCTP stack uses a single local UDP encapsulation port number as > > the destination port for all its incoming SCTP packets, this greatly > > simplifies implementation design. > > > > An SCTP implementation supporting UDP encapsulation MUST maintain a > > remote UDP encapsulation port number per destination address for each > > SCTP association. Again, because the remote stack may be using ports > > other than the well-known port, each port may be different from each > > stack. However, because of remapping of ports by NATs, the remote > > ports associated with different remote IP addresses may not be > > identical, even if they are associated with the same stack. > > > > Because the well-known port might not be used, implementations need > > to allow other port numbers to be specified as a local or remote UDP > > encapsulation port number through APIs. > Hi Xin Long, > > I really appreciate that UDP encapsulation gets implemented in Linux. > > The FreeBSD implementation initially had a bug due to missing text in > RFC6951. Please make sure the implementation also follows > https://www.ietf.org/id/draft-tuexen-tsvwg-sctp-udp-encaps-cons-03.html Hi, Michael Thanks for sharing this doc. 3. Handling of Out of the Blue Packets: This patchset can handle it well. 4. Handling of SCTP Packets Containing an INIT Chunk Matching an Existing Associations: These cases responding with ABORT, I will need to add. > > The plan is to revise RFC6951 and let RFC6951bis include the contents of > the above Internet Draft. But this most likely will happen after the > NAT document is ready and RFC4960bis finished... understand. > > If you want to do some interop testing, a web server supporting SCTP/UDP > is running at interop.fh-muenster.de. You can find a client (phttpget) at > https://github.com/NEAT-project/HTTPOverSCTP. got it.
