+1
Regards, Wassim H. On Apr 21, 2011, at 8:40 AM, Geoff Mulligan wrote: > Pascal, > We need to close on this discussion. > > Back in Hiroshima the Working Group decided that Backbone router stuff > and "address defense" across backbone routers was not going to be part > of ND draft. It appeared that the draft was getting way to complicated > and the Working Group decided to simplify things. > > I have not seen much support on the list for making these changes to > include the TID in ND. > > We need to get this draft completed. If there is a large "unheard from" > support group for these changes, please speak up or we shall move > forward with the draft as it is. > > geoff > > > > > On Thu, 2011-04-21 at 09:27 +0200, Pascal Thubert (pthubert) wrote: >> Hi Erik >> >> The TID is not a strong coupling between the H2R and the R2R operations, and >> it is not a coupling with a RPL version explicitly. >> It is an abstract information that if defined properly can be used by many >> forms or R2R interactions. >> As demonstrated by older versions of the ND spec (Backbone Router), RPL, and >> MIP. >> >> 6LoWPAN ND cannot scale if the node needs to register to all LBRs. 6LoWPAN >> ND does not define anymore any LBR interaction. >> IOW, 6LoPWAN ND lost the capability to scale when the backbone router piece >> was removed from the draft. >> Which means that it lost its capability to apply in the domains I'm looking >> at (industrial and metering). >> >> With the TID, we know that we can restore scalability in the future, and we >> know how. I do not know of a plan B. >> >> Pascal >> http://www.xtranormal.com/watch/7011357/ >> >> >>> -----Original Message----- >>> From: Erik Nordmark [mailto:[email protected]] >>> Sent: Thursday, April 21, 2011 1:25 AM >>> To: [email protected] >>> Cc: Pascal Thubert (pthubert); [email protected]; Dijk, Esko >>> Subject: Re: [6lowpan] FW: TID in ARO [was: "Advertize on Behalf" flag in >>> ARO] >>> >>> On 4/20/11 1:21 AM, [email protected] wrote: >>>> >>>> Dear Pascal and al, >>>> >>>> I support the idea of reviving the TID in ARO and DAR/DAC. Supporting >>>> a TID directly in the node initiating the initial NS appears much >>>> simpler than time stamping in the parent router. >>> >>> How would you make this work if the protocol between the routers is not >>> RPLv1, but some future version of RPL or a completely different routing >>> protocol? >>> >>> The decoupling of the host-router interaction from router-router interaction >>> has served us well in the history of the Internet. >>> >>> Erik >>> >>>> A simple and efficient method to detect mobility of hosts along a >>>> backbone of Edge Routers is an important feature to deploy backbones >>>> of Edge Routers in Buildings and should be clarified before closing >>>> 6LoWPAN WG. >>>> >>>> Cheers, >>>> Nicolas >>>> >>>> >>>> >>>> >>>> >>>> >>>> *"Pascal Thubert (pthubert)" <[email protected]>* Envoyé par : >>>> [email protected] >>>> >>>> 18/04/2011 10:37 >>>> >>>> >>>> A >>>> "Dijk, Esko" <[email protected]>, "Erik Nordmark" >>>> <[email protected]> cc >>>> [email protected] >>>> Objet >>>> Re: [6lowpan] FW: TID in ARO [was: "Advertize on Behalf" flag in >>> ARO] >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> Hi Esko, Erik >>>> >>>> The discussion on RPL and hosts should happen on the RPL list under a >>>> different topic. The point being discussed here is this: >>>> >>>> The reality is also that those (LLN) networks will need to scale to >>>> large subnets in plants, building, etc... (see the requirement drafts >>>> in ROLL). Registering to all LBRS is totally impractical. 6LoWPAN ND >>>> requires a coordination between LBRs but does not say how it happens. >>>> This problem was discussed in 6LoWPAN; the answer was in ND-01to07; >>>> and it requires a TID, for the same reason as RPL. Removing the >>>> backbone operation and the TID from the draft is ostrich policy. >>>> >>>> BTW 6LoWPAN ND needs a TID to correlate the NS and the NA as all other >>>> registrations do when strict ordering is not guaranteed (MIP being an >>>> example). Say that due to some config, a node registers a lifetime of >>>> X, then deregisters (lifetime 0), then reregisters (lifetime X) in a >>>> rapid sequence, but does not get an answer yet. Then it finally gets 2 >>>> AROs back, lifetime X and 0. What's the final state in the router? >>>> >>>> I'd like to hear what others think. >>>> >>>> Pascal >>>> http://www.xtranormal.com/watch/7011357/ >>>> >>>> >>>>> -----Original Message----- >>>>> From: Dijk, Esko [mailto:[email protected]] > Sent: Monday, >>>> April 18, 2011 10:19 AM > To: Erik Nordmark; Pascal Thubert >>>> (pthubert) > Cc: [email protected] > Subject: RE: [6lowpan] FW: TID >>>> in ARO [was: "Advertize on Behalf" flag in > ARO] > > Hello Erik, >>>>>> taking the definition you quoted: >>>>> 'host' refers to an LLN device that can generate but does not >>>> forward > RPL traffic > > the question may arise what is "RPL >>>> traffic"? It is not defined in the RPL draft > it seems. Pascal >>>> clarified to me it is traffic associated to a RPL instance, not > >>>> necessarily RPL protocol messages. This means that a host could >>>> generate > RPL traffic without being aware of the existence of RPL at >>>> all. So, _not_ all > hosts have to speak RPL? >>>>> The RPL draft does not explicitly state if "hosts" in a RPL network >>>> always > speak RPL, never speak RPL, or can be mixed RPL/non-RPL >>>> speakers. >>>>> >>>>> Taking the definition of 'node' in the RPL draft: >>>>> 'node' refers to any RPL device, either a host or a router > > >>>> rules out (?) the option that all "hosts" are non-RPL speakers, since >>>> there > may be a "RPL device" (i.e. RPL-speaking device, I assume) >>>> that is also a host. >>>>> >>>>> I communicated these perceived unclarities to Pascal and the RFC >>>> editor 2 > weeks ago. Once this is clear I think the present >>>> discussion can continue. >>>>> And then there is the related discussion of ND support for sleepy >>>> devices, > the original topic of Anders ;) > > best regards, > > >>>> Esko > > > > -----Original Message----- > From: >>>> [email protected] [mailto:[email protected]] On > >>>> Behalf Of Erik Nordmark > Sent: Friday 15 April 2011 18:39 > To: >>>> Pascal Thubert (pthubert) > Cc: [email protected] > Subject: Re: >>>> [6lowpan] FW: TID in ARO [was: "Advertize on Behalf" flag in > ARO] >>>>>> On 4/14/11 11:43 PM, Pascal Thubert (pthubert) wrote: >>>>> >>>>>> RPL can do what all classical IGPs can do WRT hosts. That is as >>>> long > > as the host address belongs to the router's prefix and stays >>>> attached > > to that router. >>>>> >>>>> I just realized that we might be talking about a different >>>> definition of "host". >>>>> What I mean by "host" is a node which does not participate in a >>>> routing > protocol, and does not forward packets (except packets >>>> explicitly addressed > to itself using e.g., a routing header). >>>>> >>>>> However, RPL has a different definition: >>>>> 'host' refers to an LLN device that can generate but does not >>>> forward > RPL traffic > > Basically per the RPL definition there is >>>> no such thing as a node which does > not participate in the RPL >>>> protocol. >>>>> IMHO what is in RPL should have been defined as a non-forwarding >>>> node, so > that we can have a sane discussion without getting >>>> entangled in terminology > issues. >>>>> >>>>> Which definition of "host" are you using above? >>>>> >>>>> Per the RPL definition there is no need for 6lowpan-nd, since all >>>> nodes will > speak RPL. This is rather confusing, don't you think? >>>>> >>>>> Erik >>>>> >>>>>> When the topology becomes multilink subnet and mobility is >>>> required > > then it is a new problem entirely, and NO, 4861 is not a >>>> suitable > > interaction with the router to allow the router to >>>> redistribute a host route. >>>>>> Because the neighbor cache that 4861 builds is not a of the same >>>>>> nature as the binding table that 6LoWPAN ND builds. Another thing >>>> that > > 6LoWPAN ND fails to express correctly. I proposed text to >>>> explain that > > (attached) but it was not considered, contributing >>>> to the illusion > > that a cache is a table. >>>>>> >>>>>> The reality is also that those networks will need to scale to >>>> large > > subnets in plants, building, etc... (see the requirement >>>> drafts in > > ROLL). Registering to all LBRS is totally impractical. >>>> 6LoWPAN ND > > requires a coordination between LBRs but does not say >>>> how it happens. >>>>>> This problem was discussed in 6LoWPAN; the answer was in >>>> ND-01to07; > > and it requires a TID, for the same reason as RPL. >>>> Removing the > > backbone operation and the TID from the draft is ostrich >>> policy. >>>>>> >>>>>> RPL already adapted to the new reality of large multilink subnet >>>> with > > inner mobility. Placing the blame on RPL is another >>>> illusionist trick. >>>>>> And this is not RPL last call. >>>>>> >>>>>> BTW 6LoWPAN ND needs a TID to correlate the NS and the NA as all >>>> other > > registrations do when strict ordering is not guaranteed >>>> (MIP being an > > example). Say that due to some config, a node >>>> registers a lifetime of > > X, then deregisters (lifetime 0), then >>>> reregisters (lifetime X) in a > > rapid sequence, but does not get an >>>> answer yet. Then it finally gets >>>> 2 >>>>>> AROs back, lifetime X and 0. What's the final state in the router? >>>>>> >>>>>> It seems we can never agree on any of this. I'd like to hear what >>>>>> others think. >>>>>> >>>>>> Pascal >>>>>> http://www.xtranormal.com/watch/7011357/ >>>>>> >>>>>> >>>>>>> -----Original Message----- >>>>>>> From: [email protected] [mailto:6lowpan- >>> [email protected]] >>>> On > >> Behalf Of Erik Nordmark > >> Sent: Friday, April 15, 2011 >>>> 1:30 AM > >> To: 6lo>> '6lowpan' >>>>>>> Subject: Re: [6lowpan] Fwd: Re: "Advertize on Behalf" flag in >>>> ARO > >> > >> > >> On 4/13/11 12:53 AM, Pascal Thubert (pthubert) >>>> wrote: >>>>>>>> Hi Erik: >>>>>>>> >>>>>>>> The RPL (DAO) sequence number allows the node to increment >>>> rapidly > >>> in case of rapid changes and then lazily when the >>>> situation is > >>> stable and DAO are scarce. The increase is >>>> strictly monotonous which > > > >>> is critical to us. >>>>>>>> >>>>>>>> A time stamp imposes a synchronization between the routers. We >>>> do > >>> not have such mechanism in RPL. A time unit (a granularity) >>>> must be > >>> agreed upon. Within that unit, movements go undetected >>>> so the time > >>> unit must be thin grained to cover rapid changes. >>>> Yet, depending on > >>> the medium, the time unit, and the size of >>>> the network, it is not > >>> necessarily easy/possible to guarantee a >>>> strictly monotonous value > >>> with a thin grained time unit. And we >>>> have limited space (2 >>>> octets) >>>>>>>> and have to deal with wrap around, which divides the space by >>>> at > > least 3. >>>>>>>> >>>>>>>> So RPL went for a sequence number. >>>>>>> >>>>>>> But the unstated assumption that RPL made is that all >>>> host-to-router > >> protocols have to now be RPL aware. That doesn't >>>> sound like good > > design. >>>>>>> A host isn't aware of whether the routers speak IS-IS or OSPF, >>>> so why > >> do the hosts need to be aware of RPL by passing some TID >>>> around? >>>>>>> >>>>>>>> I think ND has the same need as MIP for a TID == Sequence # . >>>> We > >>> know of MIP; We know of RPL. We know of the backbone router >>>>>>>> operation. We know we'll need the TID and we know exactly why. I >>>>>>>> think we should have it in the 6LowPAN ND spec right away to >>>> avoid > >>> interop issues when we add RPL and BR operations. >>>>>>> >>>>>>> I don't see a need in 6lowpan-nd for a TID; the protocol works >>>> fine > > without it. >>>>>>> I think RPL needs to be improved to deal with reality. Isn't >>>> there a > >> desire for RPL to handle 4861 hosts? Those would never >>>> know about a > > TID. >>>>>>> >>>>>>> Erik >>>>>>> >>>>>>> _______________________________________________ >>>>>>> 6lowpan mailing list >>>>>>> [email protected] >>>>>>> https://www.ietf.org/mailman/listinfo/6lowpan >>>>>> _______________________________________________ >>>>>> 6lowpan mailing list >>>>>> [email protected] >>>>>> https://www.ietf.org/mailman/listinfo/6lowpan >>>>>> >>>>> >>>>> _______________________________________________ >>>>> 6lowpan mailing list >>>>> [email protected] >>>>> https://www.ietf.org/mailman/listinfo/6lowpan >>>>> >>>>> The information contained in this message may be confidential and >>>> legally > protected under applicable law. The message is intended >>>> solely for the > addressee(s). If you are not the intended recipient, >>>> you are hereby notified > that any use, forwarding, dissemination, or >>>> reproduction of this message is > strictly prohibited and may be >>>> unlawful. If you are not the intended recipient, > please contact the >>>> sender by return e-mail and destroy all copies of the > original >>>> message. >>>> >>>> _______________________________________________ >>>> 6lowpan mailing list >>>> [email protected] >>>> https://www.ietf.org/mailman/listinfo/6lowpan >>>> >>>> >>> __________________________________________________________ >>> ____________ >>>> This email has been scanned by the MessageLabs Email Security System. >>>> >>> __________________________________________________________ >>> ____________ >>>> >> >> _______________________________________________ >> 6lowpan mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/6lowpan > > > _______________________________________________ > 6lowpan mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/6lowpan _______________________________________________ 6lowpan mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lowpan
