A nonblocking architecture for broadband multichannel switching

Abstract

The paper investigates multichannel switching as a promising alternative to traditional single-channel switching where virtual paths established in a switch are between a single input channel and a single output channel. A particular non-blocking condition is derived for flip networks, which is exploited to realize a multichannel switching architecture that supports an arbitrary number of channel groups. The architecture is internally nonblocking and bufferless. Using one flip network recursively a number of times based on the number of channel groups, the resulting architecture becomes efficient in the sense that the cross point complexity is O(N log/sub 2/ N) for N inputs. Other distinguishing features are the abilities to provide multicasting, superrate switching (i.e., rates that exceed the capacity of a single channel are accommodated), multirate switching (i.e., bit pipes of different rates are supported simultaneously), multiple performance requirements (i.e., services with different performance requirements are treated accordingly), and fair access to all inputs (i.e., no input is systematically discriminated against). In multichannel switching, cells belonging to a single session can traverse multiple channels. Providing the cell sequencing integrity becomes a challenging issue. The architecture proposed in the paper accomplishes the task without employing any cell resequencing mechanism. >