Pierrick, Kostas,
On Nov 13, 2012, at 9:20 PM, <[email protected]> <[email protected]> wrote: > Hi Jouni, Kostas, > > Please see comments inline. > > Pierrick > >> -----Message d'origine----- >> De : [email protected] [mailto:[email protected]] De la part de >> Konstantinos Pentikousis >> Envoyé : mardi 13 novembre 2012 16:53 >> À : jouni korhonen; [email protected] >> Objet : Re: [DMM] comments on draft-ietf-dmm-requirements-02 >> >> Hi Jouni, all, >> >> | "PS2: Divergence from other evolutionary trends in network >> | architecture >> | >> | Centralized mobility management can become non-optimal with >> a >> | flat network architecture." >> | >> | o What are the "other"? I would consider removing PS2 if we cannot >> |name those. >> >> I think "other" here refers to the distributed nature of delivering >> network services/content today (e.g. multiple data centers, CDNs etc.). >> It's not only the mobile that moves around these days, but your >> "correspondent" node as well. >> > > Exactly. Here, we refer to distribution of content delivery, i.e. CDN. > Probably, one of the main motivation for distributing mobility management :-) > IMHO, if we should keep only one PS, it would be PS#2 :-) Maybe we need to then say something about it like "Divergence from other evolutionary trends in network architectures such as distribution of content delivery" ? >> | "PS3: Low scalability of centralized route and mobility context >> | maintenance" >> | >> | o Isn't e.g. the SDN evolution just doing to the opposite? Highly >> | centralized management point for traffic steering? I would >> >> Oh dear, should we discuss SDN scalability here? :) No (without smile). But that is another trend to opposite direction and we should have a sufficient argument for our assertion here imho. What is so fundamentally resource consuming in "mobility context" handling that it requires distribution? Is it just a combination of all functions in one place (that has little to do with mobility per se)? >> >> >> | "REQ2: Transparency to Upper Layers when needed >> | >> | DMM solutions MUST provide transparent mobility support >> |above the IP layer when needed. Such transparency is needed, >> |for.." >> | >> | o Doesn't the "when needed" make the earlier MUST conditional? At >> |least I understand it so. If that is the case we probably could just >> say: >> | "DMM solutions SHOULD provide transparent mobility support above >> |the IP layer." ? >> >> I know we should not be talking implementation, but since I got >> inspired just now, this is the way I parse the former: >> >> procedure dmmXYZ (in: mobility_support_required, out: mobility_support) >> { mobility_support = false; ... >> if (mobility_support_required==true) then mobility_support=true; ... >> } >> >> Your proposal does not capture the conditionality of mobility support >> for different hosts, applications, and even different sessions of the >> same app. I read it more like I get the point.. but I have a slight issue here. I would need to implement the "mobility stack" whatever support function anyway even if none of my application care about it. On the other hand network based mobility should (!) be transparent to the MN or is this promise also long gone in reality? >> // set to 0 for disabling mobility support #define MOBILITY_SUPPORT 1 >> > > I agree that conditional mobility support, depending on application > capability, is a key requirement. However, I think that this requirement is > orthogonal to the distribution of mobility management functions; actually, we > may have the same requirement with centralized mobility management, right? > Basically, here, we refer to the capability of an application to use either a > home IP Yes. > address or a local IP address, depending respectively on the need, or not, > for IP session continuity. This is not really a DMM issue but a source > address selection problem and the terminal (i.e. the function tackling with > source address selection) must be able to distinguish between anchored > address/prefix and local address/prefix to make a decision. This is why we > have also suggested a work item on prefix coloring in DMM, even if the scope > of prefix coloring is larger than DMM. Agree for some obvious reason ;) >> |In Section 4.4: >> | >> | o I would just remove the sentence: >> | "Motivation: Using IETF protocols is easier to deploy and to >> | update." IMHO it brings no additional clarity what has already >> | been said. >> >> Second this too, although the section looks a bit too short then. Less is quite often more ;) - Jouni >> >> Best Regards, >> >> Kostas >> >> >> >> _______________________________________________ >> dmm mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/dmm > _______________________________________________ dmm mailing list [email protected] https://www.ietf.org/mailman/listinfo/dmm
