[Nsi-wg] Fwd: Thoughts on a basic topology model for NSI

[John MacAuley]

Jeroen,

I agree with the statement that the signal node model would perform more 
poorly for optimal path computation, but would the computation of the 
summarized meshed links not be a costly on an on-going basis?  These 
meshed links would need to be updated anytime there is a reservation 
added to the network that could impact the availability of the existing 
precomputed links.  I this model are you providing the summarized 
bandwidth available between nodes?  This would be an extremely costly 
calculation summing all potential bandwidth.

Do you have description of the mechanism used to compute the meshed 
topology?  I wouldn't mind understanding in more detail if possible.

Thank you,
John.

also suffer from being "potentially possible" topology, in that

On 10-02-09 12:23 PM, Jeroen van der Ham wrote:
> On 09/02/2010 07:37, John MacAuley wrote:
>> 1. Aggregation and summarization.
>
> I've done some simulations, analysis and have written a chapter about 
> this in my thesis. My results show that aggregating a domain to a 
> single node performs very badly compared to an aggregation model where 
> you advertise a full mesh between edge nodes.
> I would also argue that the advantages of simplifying the internal 
> domain do not balance the disadvantages you have in false positives in 
> inter-domain pathfinding.
>
> However, these simulations have only used a single layer. We're 
> currently looking at pathfinding in multi-layer networks, and we're 
> thinking about how to create aggregations for multiple layers. This is 
> a hard problem.
>
> Given the fact that current domains are not that complicated, and we 
> have a very open culture in regards to information exchange, I would 
> suggest that we leave the problem of aggregation open for now and just 
> use full topologies.
>
> Jeroen.