2012/3/27, Jiang Dong <[email protected]>: > Hi Gang and all, > > I think there are some points need to be considered between MAP series and > 4rd-U. > > 4rd-U saids "IPv4 headers can be reversibly mapped into IPv6 headers so that > 4rd tunnel packets can be designed to be valid IPv6 packets" in Section I. > In my understanding, the difference between 4rd-u and MAP-E is "IPv6 > fragment header vs IPv4 header". Both 4rd-U and MAP-E can keep the > transparency, while 4rd-U reserves 12 bytes to improve the efficiency and > MAT-E has some IPv4 redundancy octets but keep the original IP-IP > encapsulation which is easy to be operated. > > Comparing with MAP-E, 4rd-U keeps the DF bit, TOS and so on with an > additional IPv6 fragment header, which incurs reusing IPv6 option 44. > > If 4rd-U can be considered as a tunneling technique, the question is: does > it deserve adding the IPv6 fragment header in order to save 12 bytes > efficiency each packet?
Not just bits saving, but also capable of indentification with IPv6 address. Please see more detailed at draft-despres-softwire-stateless-analysis-tool-01 > If 4rd-U can be considered as a translation technique, the question is: does > it deserve adding the IPv6 fragment header in order to keep transparency? See above draft to get more information on comparision. BTW, fragmentation header is in common for MAP-T and 4rd-U. BRs Gang > > From: GangChen > Date: 2012-03-27 15:53 > To: Kevin Y > CC: Softwires WG > Subject: Re: [Softwires]Path to move forward with 4rdŠ > Hello Kevin and all, > > I actually see current multiple solution proposal from different > angle. Regarding the changes you mentioned, MAP-T/E is also doing > that, e.g. added fragmentation header to survive DF bit; change ICMP > ID filed to carry the port information. > > 4rd-U doesn't beat MAP-series. I prefer to understand the situation is > 4rd-U raised some points(e.g. CNP, Fully IPv4 transparency) which is > desirable heading to a perfect protocol design. > > BRs > > Gang > > 2012/3/27, Kevin Y <[email protected]>: >> Hi, Remi, >> >> This is beyond the charter of softwire WG, changing IPv6 address format >> needs much broad discussion in IETF community to understand its impact >> first, before we should even discuss if it is valid to design something >> like this in softwire. Have you done that ? >> >> Best Regards, >> >> Kevin Yin >> >> On Thu, Mar 22, 2012 at 10:04 PM, Guanghui Yu <[email protected]> >> wrote: >> >>> Hi Yiu >>> >>> 4rd-u changes the IPv6 header architecture (redefine >>> fragmentation header extension) and IPv6 address architecture (different >>> meaning of u-bit when g-bit=1). These are the fundamental changes. If >>> 4rd-u >>> becomes the standard, then there will be new defined 揑Pv6?packets on >>> the Internet, which are not compatible with existing IPv6 packets and >>> no existing devices can understand those packets. >>> >>> >>> Yu Guanghui <ygh at dlut.edu.cn> >>> Network and Information Center >>> Dalian University of Technology, China >>> >>> >>> On Fri, Mar 23, 2012 at 10:10 AM, Lee, Yiu >>> <[email protected]>wrote: >>> >>>> Hi Guanghui, >>>> >>>> I agree that both MAP and 4rd-u are similar technology and solving the >>>> same problem. From technical perspective, can you elaborate this a >>>> lithe >>>> bit? >>>> >>>> Thanks, >>>> Yiu >>>> >>>> From: Guanghui Yu <[email protected]> >>>> Date: Thu, 22 Mar 2012 20:26:40 +0800 >>>> To: Softwires WG <[email protected]> >>>> Subject: Re: [Softwires] Path to move forward with 4rd? >>>> >>>> I read 4rd-u draft and found it is flawed. >>>> >>> >>> >>> _______________________________________________ >>> 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
