telephony Telephony ( ) is the field of technology involving the development, application, and deployment of telecommunications services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is ...

, an international gateway exchange is a

telephone switch A telephone exchange, telephone switch, or central office is a central component of a telecommunications system in the public switched telephone network (PSTN) or in large enterprises. It facilitates the establishment of communication circuits ...

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. * Support for

echo canceller Echo suppression and echo cancellation are methods used in telephony to improve voice quality by preventing echo from being created or removing it after it is already present. In addition to improving subjective audio quality, echo suppression i ...

s. * Support for

DCME Digital circuit multiplication equipment (DCME) was a type of voice compression equipment that is installed at both ends of a long-distance telecommunication link, typically a link via communications satellite or submarine communications cable. T ...

* Support for international accounting and settlement agreements. * Support for

A-law An A-law algorithm is a standard companding algorithm, used in European 8-bit PCM digital communications systems to optimize, i.e. modify, the dynamic range of an analog signal for digitizing. It is one of the two companding algorithms in the ...

/ mu-law transcoding * High capacity (some of the largest telephone exchanges in the world are international gateway exchanges). * Support for the numbering plans of each of the countries that may be dialed. * Advanced traffic routing capabilities, in order to take advantage of the best available tariffs for each destination.

Requirements

See also