Non-blocking Networks The class of strict-sense non-blocking networks is here investigated, that is those networks in which it is always possible to set up a new connection between an idle inlet and an idle outlet independently of the network permutation at the set-up time. As with rearrangeable networks described in Chapter 3, the class of non-blocking networks will be described starting from the basic properties discovered more than thirty years ago (consider the Clos network) and going through all the most recent findings on network non-blocking mainly referred to banyanbased interconnection networks. Section . | Switching Theory Architecture and Performance in Broadband ATM Networks Achille Pattavina Copyright 1998 John Wiley Sons Ltd ISBNs 0-471-96338-0 Hardback 0-470-84191-5 Electronic Chapter 4 Non-blocking Networks The class of strict-sense non-blocking networks is here investigated that is those networks in which it is always possible to set up a new connection between an idle inlet and an idle outlet independently of the network permutation at the set-up time. As with rearrangeable networks described in Chapter 3 the class of non-blocking networks will be described starting from the basic properties discovered more than thirty years ago consider the Clos network and going through all the most recent findings on network non-blocking mainly referred to banyanbased interconnection networks. Section describes three-stage non-blocking networks with interstage full connection FC and the recursive application of this principle to building non-blocking networks with an odd number of stages. Networks with partial connection PC having the property of nonblocking are investigated in Section whereas Section provides a comparison of the different structures of partially connected non-blocking networks. Bounds on the network cost function are finally discussed in Section . . Full-connection Multistage Networks We investigate here how the basic FC network including two or three stages of small crossbar matrices can be made non-blocking. The study is then extended to networks built by recursive construction and thus including more than three stages. . Two-stage network The model of two-stage FC network represented in Figure includes matrices n X r2 at the first stage and r2 matrices X m at the second network clearly has full accessibility but is blocking at the same time. In fact if we select a couple of arbitrary matrices at 128 Non-blocking Networks the first and second stage say A. and B. no more than one connection between the n inlets of .
