1. An end-to-end publish/subscription messaging system with a middleware architecture, comprising: at least one messaging appliance configured to receive and route messages; and an interconnect utilizing channel-based messaging that routes messages over a first messaging layer based on at least one channel, each channel mapped to a subscription topic, each channel assigned to a communication pathway of a second messaging layer, wherein each messaging appliance is further configured to execute the routing of messages by dynamically selecting, in real time, a message transmission protocol and a message routing path.