In telephony, an international gateway exchange is a telephone switch that forms the gateway between a national telephone network and one or more other international gateway exchanges, thus providing cross-border connectivity.
Requirements
Whereas international gateway exchanges are commonly implemented using hardware that could also serve to build a Class 4 (national transit) switch, some of the differences between an international gateway exchange and a Class 4 switch include:
References
International gateway exchange Wikipedia(Text) CC BY-SA