Message relaying scheme based on switching in units of flows

A message relay device suitable for contructing a ultra-high-speed message relaying system is disclosed. In the message relay device, a flow is detected by a prescribed condition, while a bypass channel capable of transferring messages with an amount of calculations smaller than the case of handling messages by a default channel is set up, and the message transfer belonging to the flow is switched from the default channel to the bypass channel, while providing the connection-less communications on the default channel, so that it is possible to realize the message relaying with the ultra-high throughput by relieving the large amount of calculations inherently associated with the connection-less communications.