Le 2013-01-30 13:47, Ole Troan <[email protected]> : > Tom, > > [...] > >>> I don't at all see why moving the port mapping algorithm out of the >>> document would make things simpler. it would make it a lot more >>> complex. then you'd end up with having to support many different port >>> algorithms. >>> >>> >> My first reaction to that is to say: unless we fix a at 4, you're going to >> be stuck with implementing the a = 0 case anyway, so you might as well use >> that and exclude the lowest values of PSID if you want to keep things >> simple. The WG really needs to have an opinion on which direction to go here. > > a premise of MAP is to not put any dependency on the IPv6 addressing plan of > the ISP. excluding e.g. PSID = 0, would require the ISP > to not delegate that prefix to the end-user. that's a dependency we do not > want. > > I'm fine with fixing a to 4. > if an end user needs well known ports, give her a full address.
An alternative is possible that - permits ISPs that want it to assign well-known ports to some privileged users without necessarily giving them full IPv4 addresses; - uses a trivially simple algorithm. That which has been chosen for 4rd can be used for MAP-E as well. It uses for this an option to be used if well-nown ports must be assignable. It is specified in two sentences, in http://tools.ietf.org/html/draft-ietf-softwire-4rd-04#page-15, at the end of the first paragraph. Its complete picture representation is in a part of Figure 5: (by default) (If WKPs authorized) : : : : +---+----+---------+ +----+-------------+ Ports in |> 0|PSID|any value| OR |PSID| any value | the CE port set +---+----+---------+ +----+-------------+ : 4 : 12 : : 16 : Regards, RD >> Thinking in terms of the broader picture, I still wonder if the port mapping >> algorithm should be documented separately with MAP having a normative >> dependency on it, just so the algorithm is reusable amongst all A+P variants. > > that is really water under the bridge at this stage. > we have been there and tried that. that's how we started with MAP as the base > document, and separate MAP-E and MAP-T documents. > > cheers, > Ole > _______________________________________________ > Softwires mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/softwires _______________________________________________ Softwires mailing list [email protected] https://www.ietf.org/mailman/listinfo/softwires
