Bi-directional process-to-process byte stream protocol

(57) The system of a summary client memorizes a message (710) and sends out this message to the system of a server. A message is included in the request (702) formatted according to the protocol which can cross a firewall. The system of a server also memorizes a message and sends out this message to the system of a client. The system of a server stands by the 1st request and 2nd request from a system (740) of a client. If the 1st request is received and a specific number of messages are accumulated in the system of the server, the system of a server sends out the response corresponding to the request of 第. If the 2nd request is received (740), the system of a server sends out the response (760) corresponding to the 1st request, even if the message is not accumulated. In the following opportunity to which the system of a client sends out a request, a request includes the display of which message the system of the client received from the system of the server in the last response.