Tom, My question/concern was quite the opposite. Why logically centralised; why not even logically distributed ? I would rather think leaving it open to accommodate both (logically centralised or distributed) depending on deployment scenario, etc would be more sensible. A physically centralised one, obviously, as you said, would hardly be practically unusable.
- Manish From: "Thomas D. Nadeau" <[email protected]<mailto:[email protected]>> Date: Thursday, 28 August 2014 9:55 PM To: Manish Kumar <[email protected]<mailto:[email protected]>> Cc: Benson Schliesser <[email protected]<mailto:[email protected]>>, Osama Zia <[email protected]<mailto:[email protected]>>, "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Re: [nvo3] Second Draft Charter Update for Discussion On Aug 28, 2014:12:21 PM, at 12:21 PM, Manish Kumar (manishkr) <[email protected]<mailto:[email protected]>> wrote: Hi Benson, The same text ("A logically centralized control plane for network virtualization") was bothering me for days as well! However, having been out of touch with developments in the working group for the past few months, I thought I better do the homework to check if this has already been covered in some discussions earlier. I also see the intent of keeping out BGP and or MPLS (L2VPN/L3VPN) based solutions because work for the same is going on (or would be done) in other working groups. The final solution, as you say, could very well involve centralised and/or distributed components. Even the updated framework document talks about a balance needed - "Domain and/or deployment specific constraints define the balance between centralized and distributed approaches". Given these, as well as based on other limitations of a centralised model, I still don't understand the rationale behind the text - "A logically centralized control plane for network virtualization" in the charter update. Excluding BGP and/or MPLS based solutions for the reason above makes sense but not distributed models summarily. Am I missing something here ? I think you are. Logically centralized covers physically centralized and only allows you to have more resiliency/scale/performance than a single instance. I would also think that no one in a production environment would install a single centralized instance anyways, so we need logically centralized to cover real-world scenarios. --Tom Thanks, Manish From: Benson Schliesser <[email protected]<mailto:[email protected]>> Date: Tuesday, 26 August 2014 5:18 AM To: Osama Zia <[email protected]<mailto:[email protected]>> Cc: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Re: [nvo3] Second Draft Charter Update for Discussion Hi, Osama. On Mon, Aug 25, 2014 at 4:30 PM, Osama Zia <[email protected]<mailto:[email protected]>> wrote: 1. I am getting the impression that NVO3 WG will only look at logically centralized control plane. All decentralized solutions such as BGP based should be looked separately. Is this correct? Yes. To elaborate: Existing and new solutions that are based on BGP to provide network virtualization would be developed in the (to-be-formed) BESS working group. This would be the case for all BGP-based solutions, regardless of whether they have a control plane architecture that is distributed or centralized. It is possible that NVO3 solutions could leverage BGP and/or that BGP-based solutions could leverage NVO3 work. In these cases we would work cross-WG to make sure that the solution is documented completely and accurately, with work happening in the most appropriate place(s). For example one could imagine combining a NVO3-developed data plane encap, a NVO3-developed TS-NVE control plane, and a BESS-developed NVA control plane. (There are many other possible combinations here; I'm not trying to be exhaustive, just illustrate the idea.) Similar to what I've described above, NVO3 solutions might leverage distributed protocols in various ways, resulting in cross-WG work with other WGs. For example, it is possible that the centralized NVE-NVA control plane protocol is responsible for certain mapping functions whilst other functions are provided by distributed protocols, such as liveness detection via IGP-provided link state etc. (Again, not trying to be exhaustive, just illustrating the idea.) 2. The statement says that "The NVO3 WG will develop solutions for network virtualization based on the following architectural tenets". However, the control plane requirements and data plane requirements are optional. Shouldn't architecture be based on certain requirements? Requirements are certainly helpful, and as an NVO3 chair I do intend to encourage their development. But one of the goals of this recharter is to begin working on solutions in parallel, rather than in serial, with requirements. Indeed, the purpose of working on requirements is to assist the WG in developing solutions (requirements on their own have little value). And so with this new charter text we have given ourselves the flexibility to manage the production of requirements in whatever way is best for the WG. Cheers, -Benson _______________________________________________ nvo3 mailing list [email protected]<mailto:[email protected]> https://www.ietf.org/mailman/listinfo/nvo3
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