I have trouble understanding the concept of bisection bandwidth in high performance computing clusters.
Wikipedia article on bisection bandwidth, and online materials say that bisection bandwidth is the minimum number of links one have to cut to partition the network in two equal parts.
My understanding from reading research papers in networking (like MapReduce) keep saying that bisection bandwidth represents the "lower bound" on the bandwidth that the network can "push through". Is it a correct intuition? If yes, how do I reconcile it with the definition from Wikipedia et al.?
From a perspective of one single node, does bisection bandwidth roughly represent the average bandwidth that the node can have to any other node in the network?