2012/4/12 Behcet Sarikaya <[email protected]> > >> > 2012/4/9 Lee, Yiu <[email protected]> > >> > > >> >> > >> >> on the other hand, 4rd-u makes a tight coupling between the > address > >> >> format > >> >> and its own header mapping mechanism. this makes an operator > unable > >> >> to > >> >> have > >> >> different choices of transition mechanism as long as it chooses > >> >> 4rd-u. > >> >> if > >> >> you concern the choice of IPv6 transition mechanism, i do > recommend > >> >> MAP, as > >> >> either encapsulation or translation is operatable with MAP > >> >> address/port > >> >> mapping without difficulty. > >> >> > > [Behcet] > So you see MAP as a single protocol and say that the operator can > start with either one and then change it to the other one? >
well, easy to change in the term that the device support both and only a switch-on/off is enough to work. > Then you negate yourself saying that it may not be so easy. > not easy to change in the term that in some deployment cases (like home network), CPE are controlled by users rather than the provider, so informing them to do the switch-on/off might be a sort of work. ;-) > My simple argument then is why not start with three as some people suggested and interchange between the three? > interchangeability between the three is fine but costs. MAP modules for header processings have been ready but 4rd-u header processing module must be code and administered separately. MAP address scheme is different from 4rd-u and therefore the address mapping modules are also needed to separate. you may wonder why the address format cannot be unified. i wonder too. the story is, MAP design team was aiming to make a unified address mapping format and it has reached a rough consensus on the format, as we see now in MAP draft, where V-octet and CNP are decided by the team not to include. however, some insist they are critically important. > > All these three are different flavors of the 4rd protocol. > > Somehow you don't like to hear the words 4rd. > :) well, actually, i was the one who wrote in the MAP deployment draft that MAP is defined for IPv4 residual deployment. i like the 4rd word very much because this word helps the understanding of MAP addressing plan starting from IPv6 prefix delegation, (which is quite different from the typical use case of RFC6052). recently i avoid using 4rd (but clearly MAP and 4rd-u) just because some people recently mentioning 4rd actually refer to 4rd-u only. i respect this way of calling but avoid to make any confusion by myself. hope it clarifies. - maoke
_______________________________________________ Softwires mailing list [email protected] https://www.ietf.org/mailman/listinfo/softwires
