Hi，Peeno， In section 4.5 of the SDNAT draft you've given a mapping function example. I'm not quite get the meaning of the stateless algorithm.
Say the maxpot is 1024, so we get the i = floor((65535-1024) / 1024 ) = 63. I cannot find the definition of the P, does it mean the number of addresses in the address pool? If it is, what's the mean by floor(i / p)? Or maybe I misunderstand the meaning... Best Regards! Jiang Dong >Hello Peng, > >Some comments inline... > > >On 11/3/11 5:12 AM, "Peng Wu" <[email protected]> wrote: > >> Hi Olivier, >> >> see inlines :) >> -------------- >> Peng Wu >>> Hello, thanks for this interesting draft. >>> >>> In your use case, could you explain if every CPE/Host need to reach >>> Internet? That would be the case in a typical Broadband deployment but >>> perhaps not in your deployment scenario. >> Could be every CPE/Host. >>> >>> If all CPE needs Internet access, all of them with an IP@ need a dedicated >>> "bucket of ports" installed in the Concentrator. Which means that we could >>> just have a static allocation of ports in the Concentrator instead of >>> DHCP/PCP mechanism as described in your draft. >> Well, we've thought of this. >> There're two differences here. >> >> The first and the major one is that, if we just take ds-lite and have static >> port set allocation in the concentrator, the concentrator still has to keep >> the per-session NAT table and perform the translation, while in lightweight >> 4over6, NAT happens on CPE and the concentrator just perform >> encapsulation/decapsulation, with a per-subscriber mapping table. > >Per-session NAT is not needed if: > >- the B4 performs NAT or >- Each host has a unique IP and a known port space. > >Our implementation performs NAT without any per session state. > >> >> The second one is that in lightweight 4over6, with one-time DHCP/PCP, >> the subscriber learns its public IPv4 address. This brings convenience and >> eases the ALG problem to a certain extent. > >I think ALG is an application issue and can only be fully solved when all >applications make use of PCP. > >> In ds-lite with static concentrator >> port allocation, the subscriber still doesn't know its public IPv4 >> address/port >> without per-session PCP process. > >Yes, that is a good point. We devised an extension to PCP to return the >public IP and port range. Therefore a single message would be needed. > >>> >>> My point is we could have a Stateless mechanism in the Concentrator as >>> described in SD-NAT (draft-penno-softwire-sdnat-01) and just use regular >>> DHCP/Radius on the CPE to get a dynamic address allocation with the same >>> result. >>> >>> What do you think? >>> >>> Cheers, >>> Olivier >>> >>> >>> On 11/2/11 8:06 AM, "peng-wu@foxmail" <[email protected]> wrote: >>> >>>> Hi all, >>>> >>>> We've submitted a -04 version of the b4-translated-ds-lite draft. >>>> It describes the per-user-state IPv4-over-IPv6 mechanism with port set >>>> support, which can be achieved through some extensions to ds-lite. >>>> There are discussions going on upon this topic during and after the >>>> Interim meeting. >>>> We've received quite a lot offline comments/suggestions, and made >>>> progresses accordingly. >>>> >>>> The draft is available on >>>> http://tools.ietf.org/html/draft-cui-softwire-b4-translated-ds-lite-04 >>>> Please provide your valuable comments. And hopefully we'll present it in >>>> Taipei. >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> u--- >>>> A new version of I-D, draft-cui-softwire-b4-translated-ds-lite-04.txt has >>>> been successfully submitted by Qiong Sun and posted to the IETF >>>> repository. >>>> >>>> Filename: draft-cui-softwire-b4-translated-ds-lite >>>> Revision: 04 >>>> Title: Lightweight 4over6 in access network >>>> Creation date: 2011-10-30 >>>> WG ID: Individual Submission >>>> Number of pages: 24 >>>> >>>> Abstract: >>>> The dual-stack lite mechanism provide an IPv4 access method over IPv6 >>>> ISP network for end users. Dual-Stack Lite enables an IPv6 provider >>>> to share IPv4 addresses among customers by combining IPv4-in-IPv6 >>>> tunnel and Carrier Grade NAT. However, in dual-stack lite, CGN has >>>> to maintain active NAT sessions, which could become the performance >>>> bottom-neck due to high dynamics of NAT entries, memory cost and log >>>> issue. This document propose the lightweight 4over6 mechanism which >>>> moves the translation function from tunnel concentrator (AFTR) to >>>> initiators (B4s), and hence reduces the mapping scale on the >>>> concentrator to per-customer level. For NAT44 translation usage, the >>>> mechanism allocates port restricted IPv4 addresses to initiators in a >>>> flexible way independent of IPv6 network in the middle. >>>> >>>> >>>> >>>> >>>> >>>> The IETF Secretariat >>>> >>>> _______________________________________________ >>>> 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 _______________________________________________ Softwires mailing list [email protected] https://www.ietf.org/mailman/listinfo/softwires
