Patent ID: 7272135

Claim:
A gateway apparatus, arranged between an internet protocol network and a circuit switched network, for transmitting data received from the internet protocol network to the circuit switched network, comprising: an expansion section for expanding compressed data received from the internet protocol network; a compression section for coin pressing the data expanded by the expansion section; a setting section setting a compression form for compressing the data being transmitted to the circuit switched network, wherein the compression form includes a transmission rate; a judging section judging whether the compression form set by said setting section coincides with the compression form of the compressed data received from the internet protocol network or not; and a controller performing control such that when the compression forms judged by the judging section do not coincide, the compressed data received from the internet protocol network is expanded by said expansion section, the expanded data expanded by said expansion section is compressed by said compression section at the compression form set by said setting section, and the compressed data compressed by said compression section is transmitted to the circuit switched network, and when the compressed forms are judged to coincide, the compressed data received from the internet protocol network is transmitted to the circuit switched network without processing by said expansion section and said compression section.