A communication system using asymmetrical paths for performing asymmetrical routing using unidirectional paths for unidirectional packet communication without changing existing protocols in network systems configured for bidirectional packet communication using bidirectional paths. The communication system includes a receiver gateway installed in a satellite receiver station for performing address substitution on a packet transmitted from a personal computer (PC) to a server via an Internet network, and a transmitter gateway installed in a satellite transmitter station that receives the substituted packet and transmits the substituted packet to the server. Particularly, the transmitter gateway transmits the substituted packet to the PC from the server by transmitting the substituted packet to the receiver gateway by way of a satellite. The receiver gateway sends the substituted packet to the PC.