[Nsi-wg] Topology Use-Case

[Henrik Thostrup Jensen]

On Thu, 15 Dec 2011, Jeroen van der Ham wrote:

> Hello,
>
> One of my action points for the NSI meeting was to draft a use-case for topology descriptions. The goal is to have both proposals describe in detail the approach for topology description and how that would support pathfinding.
>
> My proposal is that both approaches outline the following:
> - Define a topology description for the Automated GOLE topology as was used during SC11 (10 networks, 4 VLANs, and their interconnections), diagram attached.
> - Describe how a pathfinding algorithm would consume the above-mentioned topologies, and then find path candidates from UvA to KRLight, and finally how to select one of the listed candidates in the following three scenarios:
> 	1) none of the networks have VLAN retagging,
> 	2) Only Netherlight supports VLAN retagging,
> 	3) All network support VLAN retagging.
> - A *short* analysis of how complex this solution is for the topology.
> - A *short* analysis of how the solution would extend to multi-layer descriptions.
>
> The goal of these proposals is to inform the NSI group on the proposals, 
> their complexity, and their future-proofness. I propose that we have a 3 
> page limit on the descriptions in order not to burden the rest of the 
> group too much.
>
> Suggestions?

I very much like the idea of a practical task.

3 pages sounds like a bit much actually, but as long as there is 
reasonable limit, it should be good.

I am missing something about what to do in the case where the complete 
topology is not available, either due to size/performance/scaling 
constraints or not being published.

Being able to demonstrate how cases with multiple technologies are 
handled. E.g., the case where both ethernet and sonet exists in the same 
network and mpls can be popped/pushed on sonet, but ethernet vlans cannot, 
and ethernet can be carried over sonet, but not vice versa. Maybe I am 
getting a bit too much ahead here.


     Best regards, Henrik

  Henrik Thostrup Jensen <htj at ndgf.org>
  NORDUnet / Nordic Data Grid Facility.