A method and apparatus for processing message is described. In one embodiment, an application programming interface is configured for receiving and sending messages. A building block layer is coupled to the application programming interface. A channel layer is coupled to the building block layer. A transport protocol stack is coupled to the channel layer for implementing properties specified by the channel layer. The transport protocol stack has a concurrent stack consisting of an out of band thread pool and a regular thread pool. The transport protocol layer is to process messages from each sender in parallel with the corresponding channel for each sender.