Virtual Cut-Through: A New Computer Communication Switching Technique

In this paper a new switching technique called virtual cut-through is proposed and its performance is analyzed. This switching system is very similar to message switching, with the difference that when a message arrives in an intermediate node and its selected outgoing channel is free (just after the reception of the header), then, in contrast to message switching, the message is sent out to the adjacent node towards its destination before it is received completely at the node; only if the message is blocked due to a busy output channel is a message buffered in an intermediate node. Therefore, the delay due to unnecessary buffering in front of an idle channel is avoided. We analyze and compare the performance of this new switching technique with that of message switching with respect to three measures: network delay, traffic gain and buffer storage requirement. Our analysis shows that cut-through switching is superior (and at worst identical) to message switching with respect to the above three performance measures.