On 15 Dec 2010, at 21:06, Eddie Kohler wrote: > On 12/15/2010 01:02 PM, Colin Perkins wrote: >>> The only way to avoid a 6-tuple is to REQUIRE (with a MUST) that the UDP ports equal the DCCP ports. In that case, the DCCP ports would be ignored on packet receipt; the UDP ports would be used for the DCCP ports as well. You can then use a 4-tuple to distinguish flows. But you cannot support a "default UDP port." >> >> NATs that rewrite the UDP ports but leave the UDP payload untouched would break this, no? > > No, they would not. Just as the encapsulated DCCP header checksum is ignored, the encapsulated DCCP PORTS would be ignored. The receiver would use the ports from UDP. In that case, we should just elide the ports from the encapsulated DCCP header to avoid the confusion, if we're going to do this. Colin
