Cache Coherent Handshake Protocol for In-Order and Out-of-Order Networks

Disclosed herein is a processing network element (NE) comprising at least one receiver configured to receive a plurality of memory request messages from a plurality of memory nodes, wherein each memory request designates a source node, a destination node, and a memory location, and a plurality of response messages to the memory requests from the plurality of memory nodes, wherein each memory request designates a source node, a destination node, and a memory location, at least one transmitter configured to transmit the memory requests and memory responses to the plurality of memory nodes, and a controller coupled to the receiver and the transmitter and configured to enforce ordering such that memory requests and memory responses designating the same memory location and the same source node/destination node pair are transmitted by the transmitter in the same order received by the receiver.