Very interesting. I was contracted a few years ago to analyze redundancy ring networks for satellites. Everyone had been trying to analyze the problem by optimizing search algorithms that essentially walked through every switch state. For a large ring, say 16 actives and 8 redundancies (backups), two problems exist--one, the analysis time is measured in years, second, the volume of information (in the trillions of path permutations) is pretty much useless. I ended up writing some algorithms that looked at connectivity patterns. Interestingly, this resulted in two things--I could tell the engineer where failures would occur (which is what they wanted to know to begin with) in about 10 seconds, and I also established a set of rules so that the program could generate optimal rings (at least from the network switching perspective--issues such as power consumption and mass were not handled!). So, by teaching myself how to look at the problem from the perspective of patterns, and then figuring out the rules for those patterns (which is really hard, BTW), I was able to do so really cool stuff! Marc Latest AAL Article My blog Join my forum!