Hey Jeroen, Your algorithm does not calculate available capacity, then; it's just reachability. That's not too expensive, but it's also not as useful. :) On Feb 9, 2010, at 4:00 PM, Jeroen van der Ham wrote:
On 09/02/2010 15:42, John MacAuley wrote:
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.
Yes, there will be a cost in maintaining an up-to-date topology. Again, reflecting on the current situation, the time between reservation is measured in days, not miliseconds, so this is not really an issue right now.
Then again, if you're doing a single node aggregation, you will be getting a lot more false-positives, which means that the clients will have to do recalculations. I am not sure how the amount of calcalations in the two situations balance out. I think that it will fall negatively towards the single node aggregation, because each client has to discover false positives himself. In the full mesh situation it's calculated once and then shared with everyone.
Do you have description of the mechanism used to compute the meshed topology? I wouldn't mind understanding in more detail if possible.
I think there are several mechanisms to do that. The one I used is very simple: for each border node we do a Dijkstra's towards all the other border nodes. If there is a path available, then we add a link in the full mesh topology. I don't do anything fancy with the metric, it's set to 1 on every link.
Jeroen. _______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg