Maoke, Thanks for the discussion (valuable a usual). More below. Le 2012-03-08 à 11:01, Maoke a écrit :
> 2012/3/7 Rémi Després <[email protected]> > > The max PSID feature, present in 4rd-u-00 and -01 (i.e. before IETF 82), was > abandoned during the Taipei meeting (November 2011) > It no longer appeared in -02 (December 29). > > Reasons of the 4rd-u fixed offset are (ref. sec 4.3 of -04): > "NOTE: The choice of the PSID position in Port fields has been guided by the > following objectives: (1) for fairness, avoid having any of the well-known > ports 0-1023 in the port set specified by any PSID value (these ports have > more value than others); (2) for compatibility RTP/RTCP [RFC4961], include in > each port set pairs of consecutive ports; (3) in order to facilitate > operation and training, have the PSID at a fixed position in port fields; (4) > in order to facilitate documentation in hexadecimal notation, and to > facilitate operation and training, have the PSID at a fixed position in port > fields." > > > Remi, > > point (1) is qualified for the individual use case but not available for the > enterprise environment, where surely it is possible that one put all well > know services under a same CE. > but if MAP or 4rd-U states enterprise use case is NOT to be supported, it is > fine. Actually, enterprise are in scope (last sentence of the ISP definition). The point that enterprise environments may have specific use cases is therefore valuable. To keep nibble alignment, and avoid unnecessary flexibility, while permitting some assignment(s) of ports 0-1023, would a rule parameter with the following two values cover your point? - Full fairness (=> offset = 4) - WKPs assignable to one CE per address (=> offset = 0) > point (2) is qualified but not a sufficient condition to derive the fixed > position of PSID. point (3) and (4) is about the human reading on the PSID. > however, the MAP or 4rd-U address has been human-unfriendly. i don't see > training and operation on easy-to-read PSID is significant. > > therefore i think MAXPSID, though it is abandoned, is a convincing reason of > having fixed position of PSID. While I understand the previous point, I don't get this one: MaxPsid could AFAIK work as well with rule-dependent offsets. This comment is just in view of keeping common understanding of issues but, since MaxPsid is now out of scope, I will have no problem if we leave the subject for the time being. RD > > - maoke > > > > Hope it clarifies. > > Regards, > RD > > > >> >> > >> > Gang >> > >> > 2012/3/2, Tina TSOU <[email protected]>: >> >> Dear all, >> >> You may be interested to comment on >> >> http://datatracker.ietf.org/doc/draft-tsou-softwire-port-set-algorithms-analysis/ >> >> >> >> Abstract: >> >> This memo analyses some port set definition algorithms which >> >> encode port set information into IPv6 address so as to support >> >> stateless IPv4 to IPv6 transition technologies, e.g. 4rd-U and MAP. >> >> >> >> >> >> Tetsuya, Simon and Tina >> >> >> >> _______________________________________________ >> >> Softwires mailing list >> >> [email protected] >> >> https://www.ietf.org/mailman/listinfo/softwires >> >> >> _______________________________________________ >> Softwires mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/softwires >> >> _______________________________________________ >> Softwires mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/softwires > >
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