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Re: [nvrg-bof] Updated charter proposal



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James Kempf wrote:
> I've actually heard the term "slices" apply to network as well as
> computation resources.
> 
> 			jak 

I have too, focusing on things like BW, not on addresses, interfaces,
paths, etc. We have a name for that - an overlay or a virtual network.
I've also heard people assert (incorrectly) that slices of existing
systems (e.g., PlanetLab) included network virtualization. Given the
confusion, the term slice may have clear meaning in a distributed OS,
but does not in networking.

I'd rather not use an ill-defined term that doesn't have a direct
relation to the WG's work, esp. in the charter.

Joe

> 
>> -----Original Message-----
>> From: Joe Touch [mailto:touch at ISI.EDU] 
>> Sent: Wednesday, June 10, 2009 12:10 PM
>> To: James Kempf
>> Cc: Martin Stiemerling; nvrg at listserv.gwdg.de
>> Subject: Re: [nvrg-bof] Updated charter proposal
>>
> 
> 
> James Kempf wrote:
>>>> Hi Joe,
>>>>
>>>> Thanx for the reply. Regarding: 
>>>>
>>>>>> Currently,
>>>>>> there is much work going on in GENI on control frameworks for 
>>>>>> provisioning a virtual aggregate (a network slice and compute 
>>>>>> resources).
>>>>> This is not network virtualization. I.e., when we deal 
> with an OS, we 
>>>>> don't try to standardize the provisioning of memory, processing 
>>>>> capacity, etc. Processes don't ask for 20% of a CPU; they 
> just ask to 
>>>>> run. Processes don't ask for 20% of memory, they ask for 
> it in terms 
>>>>> they need (bytes).
>>>>> Similarly, virtual networks ask for resources in terms they need 
>>>>> (addresses, links, and reserved link capacity, i.e., 
> provisioning). 
>>>>> We need a common way to express how to virtualize the 
> network (which 
>>>>> most "virtualization" systems don't really do anyway) 
> before we can 
>>>>> standardize how its resources are manged.
>>>> GENI has the notion of RSPECs which I believe are designed to allow 
>>>> virtual network providers to ask for resources. There has also been 
>>>> some recent work in 4WARD along these lines. Are you saying 
> that the 
>>>> way these proposals are designed doesn't really address the need or 
>>>> perhaps that they need some modification?
> RSPECs, like many things in GENI, focus on services and 
> computation - i.e., OS resources, not network resources 
> (e.g., addresses, interfaces, virtual links, etc.) - at least 
> according to the March 2008 slides I could find on the topic.
> 
>>>> One of the issues we've been discussing here at ER is that there is 
>>>> already a collection of deployed data plane techniques to support 
>>>> network virtualization. For dedicated bandwith, the techniques run 
>>>> from dedicated lambdas up to MPLS LSPs in IP networks and PBB-TE 
>>>> tunnels in Metro Ethernet. For nondedicated bandwidth, 
> there are IP-IP 
>>>> tunnels, maybe one could even view HIP as a kind of tunnel. 
> Are these 
>>>> techniques insufficient?
> There are lots of building blocks, and a few systems that 
> create network architectures out of them (which is more than 
> just the building blocks).
> We need to develop a common framework for virtualizing the 
> *network*; then we can engage groups like GENI about how to 
> organize distributed resources on it.
> 
>>>> If you grant that these techniques are sufficient, then the primary 
>>>> issue becomes how to  construct a virtual network in a 
> cross provider 
>>>> way. This today, as far as I can determine, is impossible except if 
>>>> you run over IP.
> It can be done at IP, MPLS, or ethernet, as well as some 
> other less ubiquitous ways today.
> 
>>>> The issue you cite above, namely how to name and allocate 
> resources, 
>>>> is a big one, also interoperability between providers to allow the 
>>>> slices to be plumbed together.
> Slices, AFAICT, refer to a group of (virtualized) OS 
> resources. It's not useful to talk about those resources 
> until the *network* resources are virtualized and coordinated.
> 
>>>> There is also a question of
>>>> timescale. Most providers require a timescale of days to set up a 
>>>> virtual network like a VPN. I believe the vision of most 
> researchers 
>>>> is such virtual networks to be available on demand.
> You're jumping a few steps ahead. IMO, the steps are:
> 
> 	- define a common virtual network framework
> 	(what this BOF is for)
> 	- determine how providers can offer VNFs as a service
> 	- determine how to provision a VNF across providers
> 	- integrate VNFs with slice reservation systems
> 
> We're at step one here.
> 
>>>> So our view on this is that the work is primarily needed in 
>>>> constructing a control plane that allows virtual network 
> slices to be 
>>>> constructed from resources obtained from different ISPs by 
> a virtual 
>>>> network provider. And then to connect the network resources 
> up to end 
>>>> host resources (which may involve clouds or end host virtual 
>>>> machines). This seems to me what GENI is trying to address, maybe 
>>>> Trilogy and Akari as well (I am not that familiar with them).
> It's hard to consider discussing a control plane when we 
> haven't yet defined what to control. Slices don't include 
> network interfaces or addresses as a virtualized, localized 
> resources - that is the purpose of network virtualization, 
> and it is useful independently of a slice. So let's start by 
> decoupling the two, and solve the network virtualization 
> problem first.
> 
> Joe
>>
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