Superconcentrator

Summary

A superconcentrator is a graph with two designated and equal-sized subsets of vertices $I$ and $O$, such that for every two equal-sized subsets $S$ of $I$ and $T$ of $O$ there exists a family of disjoint paths connecting every vertex in $S$ to a vertex in $T$. Some sources require in addition that a superconcentrator be a directed acyclic graph, with $I$ as its sources and $O$ as its sinks.