On 25/7/07 12:32, "Mark Handley" <M.Handley@xxxxxxxxxxxx> wrote: > OK, here's a draft draft on the issue. I think this is in keeping > with your mail, but provides background too, and I think changes how > IANA allocates DCCP ports. Comments? Flames? > > Shall I turn this into a proper draft, or is there disagreement on this? > > Cheers, > Mark Thanks for the text. The SC draft can be cleaned-up a lot on the basis of this and the discussions from this IETF. The history gives a useful summary of how things evolved, and seems consistent with my recollections. I'll rewrite with this and what you said at the Mic in the meeting. My understanding was that the section on "Sockets, Ports and Service Codes" reflected what was written in SC draft - although I'd be keen to rework the text. " or example DTLS connections and unencrypted connections for the same application will normally use different service codes to distinguish them, but as it is the same application, it makes sense to use the same port." - seems OK (if the receiver OS supports this). You then say: "The requirement on the host stack would be that the service code of the incoming connection request can be made available to the application, so that the application can correctly process the data without requiring some application-specific method to distinguish the two types of data." And "A DCCP implementation SHOULD provide a way for the application accepting the connection to discover the service code used in the DCCP-Request packet." - Are you suggesting that after the socket has been opened, the application THEN should call down to the protocol control block to figure out what SC was received? - or the API requires the application to associate a single SC with EACH listening socket? " Second, more than one application might need to bind to the same server port, using different DCCP service codes." - I think we all agree. "We revise RFC 4340 as follows: IANA should allocate well-known DCCP ports on demand to anyone to applies, without requiring a specification or additional justification. Each well-known port request MUST be for a specific registered DCCP service code. IANA should use an allocation policy that attempts to minimize server port collisions, but it is expected that the same well-known port will sometimes be allocated to more than one service code. " - I need to think on this. DCCP Service Code 0 - I proposed to remove the "Minimal Support" text, as per slides at the Chicago meeting. I'd like to check the implementor's take on this one. Gorry
