[Olsr-dev] Freifunk Testing

[L. Aaron Kaplan]

On Jun 14, 2008, at 10:47 PM, elektra wrote:

> Hi -
>> btw: Is there a reason for an TC Interval of 2 at an HELLO  
>> Interval of 5? that
>> would be 2 TCs before the linkcost of a link could change...
>>
> there is. This is to avoid routing loops even when links are saturated
> with payload traffic. Not all TC updates are likely to come through
> under these circumstances, so redundancy helps here. (But even when
> sending TCs twice as frequently as Hellos,  Olsrd did loop  
> occasionally
> when we were testing it at the Meraka 'Massive Mesh' grid under high
> payload.) To get entirely rid of routing loops, TC redundancy has  
> to be
> even greater. But the resulting protocol overhead is much more severe
> then occasional routing loops that persist for a couple of seconds.  
> This
> is a limitation of the protocol design.

Let me try to clarify things a bit:
routing protocol traffic should *always* be prioritized and get thru.
Otherwise you are in a dangerous situation anyway (oscillations,  
flapping etc etc).

And yes, I believe that we can all learn from cell phone networks in  
this respect.
And no - I don't believe that flooding is a good answer to this problem.

a.