International telephone Network International Telephone Network
In each country's long-distance telephone network, one or several long-distance exchange centers are connected directly with the International import and Export Office of the International telephone network to complete the international calls.
An international telephone network consisting of international exchange centres (ISC) and several international Interchange Centres (ITC) of various countries (or regions). The International Exchange Centre, also known as the International Import and Export Bureau, has the task of connecting the International telephone network and the domestic telephone network.
The international telephone network is characterized by a far-distance communication and a majority of the non-contiguous between the majority of countries. Most of the means of transmission is the use of long relay wireless communication, satellite communication or submarine coaxial cable, optical cable, etc. widely used in communication technology to reduce transmission costs, the use of an echo suppressor or an echo Canceller to overcome the long distance four-line transmission delay caused by the echo-ringing phenomenon.