On 6/11/2015 5:30 AM, go...@erg.abdn.ac.uk wrote: ... >> - Port multiplexing, with application-to-port mapping during connection >> setup: > > GF: Thinking on this, is application-to-port mapping really a TCP > function? port-mapping is similar in other transports, and doesn't really > have any different support in TCP (contrast to the Service Code in DCCP)
The assumption of app-to-port mapping is part of how assigned ports are, well, assigned. >> Note that in the presence of network address and port translation >> (NAPT), >> TCP >> ports are >> in effect part of the endpoint address for forwarding purposes. >> > GF: This is the case only for those middle boxes that do NAPT, > load-ballancing etc, saying they are part of the endpoint address is to me > confusing forwarding by middle boxes from forwarding by routers - I'd > prefer to be more careful here. Ports are part of the connection identifier, in conjunction with the endpoint address. The fact that NATs or any other devices remap, translate, or overload that function (i.e., using it for forwarding decisions) is not relevant to TCP's view of these values or to the service TCP provides, IMO. Joe _______________________________________________ Taps mailing list Taps@ietf.org https://www.ietf.org/mailman/listinfo/taps
