[OLSR-users] network problems

[Holger Mauermann]

Andrew Hodel wrote:
> This is all I have found on the subject: 
> http://64.233.187.104/search?q=cache:pwVvfEXsyRgJ:lion.cs.uiuc.edu/courses/cs497hou/mbw.ppt+packet+pair+bandwidth&hl=en&client=firefox
>  & 
> http://64.233.187.104/search?q=cache:ZkmvmlorR9QJ:pdos.csail.mit.edu/decouto/papers/hsu97bandwidth.pdf+bandwidth+routing&hl=en&client=firefox

A click on http://www.google.com/search?q=packet+pair should give you
much more reading ;-)

Here is a short description of the Packet-Pair technique, quoted from
http://research.microsoft.com/mesh/papers/multiradio.pdf

"...Each node sends two back-to-back probe packets to each of its
neighbors every minute. The first probe packet is small (137 bytes),
while the second probe packet is large (1137 bytes). The neighbor
measures the time difference between the receipt of the first and the
second packet and communicates the value back to the sender. The sender
takes the minimum of 10 consecutive samples and then estimates the
bandwidth by dividing the size of the second probe packet by the minimum
sample. Note that this estimate is not very accurate, since it ignores
several factors that affect packet delivery time. However, the estimate
is sufficiently accurate to distinguish between links of significantly
different bandwidths..."

> I am willing to help any way I can.

Of course me too!

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