On Tue, Oct 7, 2014 at 7:33 PM, Sri Gundavelli (sgundave) <sgund...@cisco.com> wrote: > > Hi Thomas, > > > > No. Let's please not go here. > > No .. no. My comment is not intended to argue against inventing a new > approach; I'm not in the way. But, if we do not discuss and show a > reasonable technical argument as why an option needs to be ruled out, I > suspect we will end with the exact same answer, but with a different > technology title and functional entities. I'm more curious to understand > how the VM mobility properties/requirements are any different from IP > mobility requirements of a classical mobile node. In today's deployments, > that classical mobile node is not always a cellular device /laptop, but > can also be a mobile router, IOT device with no user association. > > > IP Mobility protocols are providing layer-3 mobility to a device. There is > very little relation to the user. If the device moves by itself, or if the > user moves it physically, the protocol has no clue. If there exists any > relation to the user, its only about using the access authentication of > the user and binding that identity to the mobility session. But, even such > user relation is not present in mobile router/IOT deployments. The core > protocol only deals with signaling and managing the forwarding state. > There is no user identity semantic in the data-plane. > > If a mobile node changes its point of attachment in the network, because > the owner of the device moves it, or when a VM moves across L3 boundaries > due to the administrator triggering a VM migration may not mean any thing > to the protocol underneath. If we take CDMA2000, the MIP stack is in the > chipset and there are many IOT devices with the cellular interface and > there is still IP Mobility for the device without a user operating it. > > > > > > the entire physical device is mobile, > > This is a good point. But, however you look at it, the "Virtual Machine" > construct is presenting the view of a separate IP node. It has an > Operating System, set of applications, a logical interface card, IP > address configuration, forward stack, and a set of resources. Applications > are able to bind to an address, TCP/UDP ports and are able to send/receive > IP traffic. That Virtual Machine entity as a whole is moving across > networks. Now, why would it matter for layer-3 mobility protocols to be > aware of this subtle difference on a real mobile device, vs a VM instance > ? Why is it relevant from the forwarding point of view ?
You've reverted to posing the networking virtualization problem in terms of virtual machines which leads to a use case specific solution-- this is exactly the reason I suggested to not use the term. The general problem is not (virtual) machine migration, it is a problem of moving networking state between hosts and adapting the network to be aware of this. > > > > > > > Finally, in MIP, the mobile device itself *knows* it is mobile and > >actively participates in that mobility. > > There exists two mobility models; Client-based and network-based. For the > later, there is no such assumption on the client awareness. The network is > responsible for providing the mobility. > > > > Regards > Sri > > > > > On 10/7/14 9:54 AM, "Thomas Narten" <nar...@us.ibm.com> wrote: > > >> =====> Now, if I replace "VM" with "mobile node", that's layer-3 > >> mobility and we have few solution options thereŠ > > > >No. Let's please not go here. As David pointed out in a different > >thread, NVO3 is about VM *migration*. > > > >Mobile IP is a very different beast built on a number of fundamentally > >different assumptions. E.g., in mobile IP, the entire physical device > >is mobile, not just a VM. Also, the physical device is moving, i.e., > >because its owner is carrying it around. In the DC, the VM is moving > >because the DC operator wants to move it. Finally, in MIP, the mobile > >device itself *knows* it is mobile and actively participates in that > >mobility. In data centers, the VMs are oblivious to being moved and > >are not themselves actively involved in any of the signaling or steps > >of the move. > > > >Thomas > > > >_______________________________________________ > >nvo3 mailing list > >nvo3@ietf.org > >https://www.ietf.org/mailman/listinfo/nvo3 > _______________________________________________ nvo3 mailing list nvo3@ietf.org https://www.ietf.org/mailman/listinfo/nvo3
