Patent ID: 7076519

Claim:
A server-client system, wherein a client terminal is connected to a server through an ISDN network; wherein said server comprises notification means for transmitting to said client terminal, via a D-channel, a notification that a large volume of data is to be transmitted, when data, whose volume is greater than a predetermined volume is generated, transmission means for transmitting the large volume of data to said client terminal via a B-channel, upon reception of a notification of data transmission allowance from said client terminal and for entering into a transmission allowance waiting state during which the large volume of data is not transmitted to said client terminal upon reception of a notification of data transmission non-allowance from said client terminal; and wherein said client terminal comprises monitoring means for monitoring a state of all B-channel lines between said client terminal and said server, upon reception of the notification that a large volume of data is to be transmitted from said server; a transmission allowance notification means for transmitting to said server, via a D-channel, the notification of data transmission allowance when two or more B-channel lines are free and for transmitting to said server, via a D-channel, the notification of data transmission non-allowance when two or more B-channel lines are not free.