Re: [vnrg] way forward on VNRG definitions

[Didier Colle <[e-mail]>]

Dear Martin, all,

> - Inter-domain-wide operation across multiple administrative domains.
>  Comparable to the issues in QoS research we may be able to easily
>  provide dedicated services to users within our domain, but providing
>  these services inter-domain-wide may have some technical or business
>  constraints. 
I tend to disagree with this point.
The abstraction as part of the virtualization should hide whether 
resources belong to one or multiple domain.
Scenario I am thinking of: global network service provider X and global 
network service provider Y obtain guaranteed virtual resources from 
virtual infrastructure provider P who aggregates and VIRTUALIZES 
resources (probably also partly virtual resources) obtained from local 
infrastructure provider A and in another local infrastructure provider 
B. Those local infrastructure providers might also deliver virtual 
resources directly to local service providers xa, xb, ya and yb.

Having said that, doing is much harder than saying a couple of words. 
Still I believe the abstraction and aggregation features of 
virtualization should enable overcoming multi-domain issues.
You are right, business constraints can probably not be solved by 
virtualization (probably not by any technical solution...). Having said 
that: what is the business scenario in which a provider delivers virtual 
network instances but putting in place business constraints preventing 
extensions to other domains?

Kind regards,

Didier

Martin Röhricht wrote:
> Dear Joe,
>
> On 08.06.2010 18:57 Joe Touch wrote:
>> As a starting point, we would like to have everyone on the list 
>> answer the
>> following questions. We would prefer short text rather than full 
>> paragraphs
>> extracted from any I-D or other document.
>> -----------------------------------------------------
>>
>> Starting questions:
>>
>> 1. how do you define VNs?
>
> A VN is a network that appears to its users as an ordinary network by 
> providing ordinary interfaces and services but which is actually 
> decoupled from the physical substrate.
>
>>     1.a. what are the key components?
>
> Virtual nodes, virtual links, management entities
>
>>     1.b. what is the relationship between these components?
>
> An arbitrary number of virtual links may be spanned between an 
> arbitrary number of virtual nodes.  A physical node may be equipped 
> with multiple virtual nodes.  Virtual links are controlled by 
> management entities residing on physical nodes and acting as mediators 
> between pyhsical and virtual nodes.
>
>>     1.c. what is the characteristic behavior/capability of the
>>     resulting system?
>
> The resulting virtual network provides its users the illusion of using 
> a dedicated (physical) network with a set of guaranteed resources.  It 
> should provide its services isolated from other virtual or physical 
> networks that actually run on the same hardware.  Network management 
> operations should be performed transparent for the network's users, 
> e.g. by migrating nodes or links in the physical substrate.
>
>> 2. what are VNs used for?
>
> VNs may be used to provide a dedicated network for its users which 
> operates isolated from any other network traffic.  They may be used to 
> bring out completely new network architectures and protocols.  They 
> may be used to optimize resource utilization either via aggregating or 
> via distributing resources used for a virtual network.
>
>> 3. what are they key challenges?
>>
>> for each challenge:
>>     - define the challenge
>>     - explain why it is hard
>>     - provide some references to those working on solutions
>
> - Instantiation of virtual nodes and virtual links.  How can we a
>  priori determine whether a virtual node exists or is actively running?
> - Inter-domain-wide operation across multiple administrative domains.
>  Comparable to the issues in QoS research we may be able to easily
>  provide dedicated services to users within our domain, but providing
>  these services inter-domain-wide may have some technical or business
>  constraints.
> - Dynamic and on-demand instantiation of virtual networks.  Instead of
>  using a manual or semi-manual (e.g. script-based) configuration of
>  virtual networks, it may be desirable to use signaling protocols for a
>  dynamic and on-demand management of virtual networks.
> - Network topologies. Talking about virtual networks, we may wish to
>  not only control some virtual nodes and virtual links, but also create
>  virtual network topologies, such as full-meshed networks, rings,
>  trees, etc.
> - Attachment of end-users---are they part of the virtual network? How
>  do we cope with the mobility of end-users, again inter-domain-wide?
> - Aggregation---to what level can we aggregate traffic by still
>  preserving isolation and by not losing flexibility to migrate virtual
>  nodes and virtual links to another location?
> - Security---how can security be achieved?  Is it an integrated part 
> of the virtual network architecture and transparent to its users?
> - AAA---using virtual network resources breaks down to actually using
>  physical resources of one or more network operators.  How do we
>  provide authentication, authorization, and accountability?  How do we
>  provide these AAA services inter-domain-wide?
> - Are Quality-of-Service guarantees an inherent requirement for virtual
>  networks? If yes, to what extent?
> - Providing the users the opportunity to create completely new network
>  architectures and protocols inside their virtual networks---how do we
>  cope with interoperability?  Or do we run the risk of creating an
>  »inverse Internet«?
>
>
> That's it for now.
>
> Martin
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-- 
Didier Colle
Ghent University - IMEC - IBBT
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