International gateway exchange

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: International variants of signalling protocols, such as International ISUP and #5, in addition to the relevant national signalling protocols.

Source: Wikipedia — International gateway exchange (CC BY-SA 4.0)