[Olsr-users] getting second best route from dikjstra's algorithm

[Teco Boot]

The trick is to converge to something that works well. L2 feedback may play an important role. Give the 2nd best route a chance and find out its L2 behaviour makes sense. Before the 2nd best route is taken, we must make sure there isn't a micro-loop.

Teco


Op 14 jun. 2013, om 09:12 heeft Henning Rogge het volgende geschreven:

> On 06/14/2013 09:07 AM, Vigneswaran R wrote:
>>   +---- J --------- K -------+
>>  /                            \
>> A --- B --- C --- D --- E ---- F
>>        \                      /
>>         +-- M -- N -- O -- P-+
>> 
>> 
>> You're right. In the above scenario, A thinks that B,C,D,E,F is the
>> second best path. However, as far as B is concerned, M,N,O,P,F is the
>> 2nd best path. When we apply policy routing uniformly on all the routers
>> to use 2nd best path (for a particular traffic), traffic from A to F
>> will flow through B,M,N,O,P,F instead of B,C,D,E,F (and which remains
>> unused).
> 
> It might be even worse. Think about a network like this:
> 
>  B---C---D
> / \ / \ / \
> A   X   X   H
> \ / \ / \ /
>  E---F---G
> 
> A might decide that A-B-C-D-H is the best path and A-E-F-G-H is the second best one.
> 
> But E decides that E-F-G-H is the best one and E-C-D-H is the second best one, pushing the traffic back onto the best path from A to H.
> 
> Henning Rogge
> -- 
> Diplom-Informatiker Henning Rogge , Fraunhofer-Institut für
> Kommunikation, Informationsverarbeitung und Ergonomie FKIE
> Kommunikationssysteme (KOM)
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