[Nsi-wg] Topology virtualisation

[John MacAuley]

So it looks like there are requirements for both resource exclusion and 
inclusion.  Inclusion is a tougher path computation issue. Are we 
putting this into release 1.0 of the protocol?


On 10-06-27 10:20 PM, Gigi Karmous-Edwards wrote:
> Jeroen,
>
> I agree, that if a user has a preference on which domains to include 
> during path computation, then: 1) that should be communicated via the 
> NSI and 2) that the path computation entity computes the path based on 
> user requirements.
>
> We might not ever have a completely globally GOLE-interconnected 
> network, however, I do think the roles of GOLEs are different than 
> regular network domains and that in most cases interconnecting domains 
> via GOLEs may result in simpler and shorter paths.
>
> Gigi
>
> Jeroen van der Ham wrote:
>> On 25/06/2010 15:14, Gigi Karmous-Edwards wrote:
>>    
>>> I agree that the removal of non-GOLEs from the topology graph is an
>>> alternative to creating a constraint during path computation. I thought
>>> that the removal from the graph would be easier, similar to removal of
>>> failed links (due to availability etc ) during crank-back.  Having said
>>> that, in GIRRA, both technology and policy is taken into account but
>>> availability is not. This is because we do not collect availability
>>> information only relatively static  information about the topology,
>>> therefore reducing complexity and the number or required updates.
>>>      
>>
>> Availability is then taken into account using crank-back.
>>
>> As we discussed before, it remains to be seen whether the number of
>> updates regarding availability outnumbers the load on the network due to
>> crank-backs.
>>
>>    
>>> With reference to your other comments about policy: having an open
>>> policy GOLE makes path computation easier, since the fewer "policy-rich
>>> " domains one has in the computed path the better. IMHO, an ideal global
>>> path will consist of only the source and destination domains and the
>>> rest of the path will consist of policy-free GOLEs. Leaving the policy
>>> of the path to the two endpoint domains only. Does this make sense?
>>>      
>>
>> This will really depend on the user! I would imagine that LHC Tier-x
>> users do not want to use GOLEs, but instead want to make use of the
>> LHCnet as much as possible.
>> I realise that the LHC is an extreme case, but similar cases can be made
>> for NLR/Internet2, GEANT, GLORIAD and other networks that some but not
>> all users have access to.
>>
>> Leaving policy out of the equation like this may make pathfinding a
>> whole lot simpler, but I'm not sure whether you end up with answers that
>> you can work with.
>>
>>    
>>> I do realize that this is different than traditional approach and I
>>> realize that today in our real world,  GOLEs are not all interconnected.
>>> The above statements are based on an "ideal" network.
>>>      
>>
>> Given the examples I made above I'm not sure that we'll ever end up with
>> anything resembling an "ideal" network as you describe.
>>
>> Jeroen.
>>    
>
>
> _______________________________________________
> nsi-wg mailing list
> nsi-wg at ogf.org
> http://www.ogf.org/mailman/listinfo/nsi-wg
>    

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.ogf.org/pipermail/nsi-wg/attachments/20100627/d6b1f1da/attachment.html