End-to-end credit-based flow control system in a digital communication network

An improvement to a system for controlling traffic in a digital communication network eliminates the necessity for separate buffer queues in a credit-based traffic control system by providing switches at intermediate nodes that provide credit numbers back to the source reflecting either credit numbers from downstream nodes or the numbers of buffers allocated to virtual connections at the node, whichever is the smaller. In one embodiment, this is accomplished by dividing the buffers at a node among the number of virtual connections at that node to establish a number of buffers, each allocated to a different virtual connection, and comparing the numbers of credits received at that node with the number of buffers. Thereafter, data cells are transmitted only in accordance with that credit number such that the amount of data transmitted down the virtual channel is limited to that which can be processed at the node with the fewest or most restricted buffers, whereby data may be immediately transmitted to other nodes without loss.