> On 19 Feb 2008, at 18:43, Dan Wing wrote: > ... > > DCCP has an initiation handshake. It seems effective, to me, > > to define SRV records that are something like this: > > > > _foobar._dccp SRV 0 0 1234 server.example.com. > > _foobar._dccp-udp SRV 0 0 1234 server.example.com. > > > > and protocol foobar then tries both a native DCCP handshake > > (to DCCP port 1234) and a DCCP-over-UDP handshake (to UDP > > port 1234). We could do the native DCCP first and try > > DCCP-over-UDP 100ms (or whatever you like) later. > > > > This provides the incremental deployment we need (with > > dccp-udp) and provides an easy path to real DCCP deployment > > (where the UDP encapsulation is not necessary because there > > are no meddling on-path IPv4 NATs). > > > > Would this be feasible? > > Sure, but is it needed? If you want DCCP-over-UDP > encapsulation to be > seamless, then surely you need to try it every time a native > connection attempt fails. In that case, there's no need for separate > signalling. What do you mean by 'separate signaling' -- are you referring to the SRV record with _dccp-udp? I worry that the DCCP-UDP port might need to be different than the DCCP-RAW port. Are you expecting them to always be the same? That should be a reasonable assumption most of the time, but I worry it might not work in some case. -d
