Re-, Please see inline.
Cheers Med -----Message d'origine----- De : Nejc Škoberne [mailto:[email protected]] Envoyé : mardi 16 août 2011 14:01 À : BOUCADAIR Mohamed OLNC/NAD/TIP Cc : [email protected]; [email protected] Objet : Re: [Softwires] draft-operators-softwire-stateless-4v6-motivation Dear Med, [SNIP] > [NS: I don't think this is true only for stateless > solutions. If we have a stateful solution with static port allocation > (as you mention in section 3.1.3), then implementing such an implicit > host identification which uses also port information, is doable as > well.] > > Med: I Agree. But then you loose other benefits of the stateful: have an > aggressive address sharing ratio. You indeed loose agressive sharnig ratio, but you have somewhat more flexible addressing. Also, the CPEs can be then really simple devices, excluding any of the NAPT functionality, doing only stateless encapsulation. However, what you loose/gain is irrelevant for my point. I think this section should be modified in a way like the logging section or any other appropriate way, which explains, that this is not the benefit of the stateless nature, but rather the benefit of the static port allocation. Med: Your point is valid and the text should be updated accordingly. My comment aims to show that the comparison is not so that trivial. We can claim the stateful with port ranges can provide similar features as the stateless or the binding mode but we always forget to mention this lead to loose one of the characteristics of the stateful. We captured a similar discussion in http://tools.ietf.org/html/draft-operators-softwire-stateless-4v6-motivation-01#section-4.2: "5.2. Port Utilisation Efficiency CGN-based solutions, because they can dynamically assign ports, provide better IPv4 address sharing ratio than stateless solutions (i.e., can share the same IP address among a larger number of customers). For Service Providers who desire an aggressive IPv4 address sharing, a CGN-based solution is more suitable than the stateless. If a Service Provider adopts an aggressive address sharing ratio, it is likely to be attempted by enforcing a NAT port overloading mode and as a consequence some applications will break. However, as more and more hosts become dual-stack enabled, the need for ports in IPv4 is likely to decrease. The insurance to have the full set of 64K ports per host will be one of the incentives to have them IPv6 capable. Moreover, Service Providers should offload some services to IPv6 (e.g., DNS, VoIP)." _______________________________________________ Softwires mailing list [email protected] https://www.ietf.org/mailman/listinfo/softwires
