Patent ID: 6892240

Claim:
A bidirectional communication method between a server and each of a plurality of clients through an HTTP (Hyper Text Transfer Protocol) communication gate allowing only HTTP traffic to pass through, the method comprising the steps of: a) establishing two connections between the server and the client; b) setting one of the two connections to an upstream connection using POST method of HTTP to allow real-time data transfer from the client to the server, c) setting the other of the two connections to a downstream connection using GET method of HTTP lo allow real-time data transfer from the server to the client; and d) transferring data between the server and the client through the upstream connection and the downstream connection, wherein the real-time data transfer is inhibited between the client and the server until the two connections have been completely set up; wherein the HTTP communication gate is an HTTP proxy having a caching function; at the client, e) adding a temporary unique character string, which is different from previous temporary unique character strings used by the client and by other clients, to content location information of each of a POST-method HTTP header and a header of a data cell so as to avoid the caching function of the HTTP proxy; and at the server, f) ignoring the temporary unique character string added in the content location information received from the client.