Nonblocking multicast Clos networks
Yujie Wan, Tony T. Lee · 2010
This paper studies the necessary and sufficient nonblocking conditions for multicast Clos network or v(m, n1, r1, n2, r2) network, wherein there are r1/r2switch modules at first/third stage, n1input/n2output ports on each first/third stage switch module, and m central stage modules. We prove that given constant n1, n2, if r1≥ L = n2((m over n2−1)−1)+1, r2≥ n1n2(L over n2), m ≥ n1n2is a necessary and sufficient nonblocking condition. Analogy to point-to-point Clos network, this result is independent of r1,r2and improves on the current best sufficient condition at the given region. We also present a wide-sense nonblocking routing algorithm for satisfying each input multicast call.