Deadlock-Free Packet Switching Networks

Deadlock states have been observed in existing computer networks, emphasizing the need for carefully designed flow control procedures (controllers) to avoid deadlocks. Such a deadlock-free controller is readily found if we allow it global information about the overall network state. Generally, this assumption is not realistic, and we must resort to deadlock-free local controllers using only packet and node information. We present here several types of such controllers, we study their relationship and give a proof of their optimality with respect to deadlock-free controllers using the same set of local parameters.