[e2e] fast restoration/protection

Jon Crowcroft Jon.Crowcroft at cl.cam.ac.uk
Thu Jun 15 06:28:04 PDT 2006


to clarify - what happens in a link state protocol is that you
distribute states each epoch to all routers who construct a RIB
and do a dijkstra to compute a local FIB - what i am saying is
save the output of the dijkstra for all cases you see, and then 
when you get a link state delta that _matches_ the FIB for a previous
case, load the FIB immediately

for distance or path vector, this is harder as you need to add info
(BGP in practice already has loadsa add ons to achieve some of these
effects in an ad hoc way, but it might be nice to do it in some sort
of principled fashion:-)

In missive <E1FqqRl-0000uA-00 at mta1.cl.cam.ac.uk>, Jon Crowcroft typed:

 >>there's loads and loads of fancy algorithms for computing alternate
 >>routes and building k-resiliency etc etc, but does anyone know if
 >>there's a paper on the obvious - if routers were to log routing
 >>tables, and then one correlated this with faults, one could simply
 >>_load_ the alternate forwarding table directly after a link or node
 >>outage from the previous time there had been an outage at that point -
 >>i.e. simply use the fact that the routing system is a distributed 
 >>algoriithm for path finding, but give it some memory:)
 >>
 >>j.

 cheers

   jon



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