It is a device capturing and controling all the signals, which are being created by the whole system, especially the made and received phone call signals. The device is mostly used for connecting regular phone system with the Internet and backwards.
AT&T Inc. is a premier communications holding company in the United States and worldwide. Operating globally under the AT&T brand, AT&T is recognized as the leading worldwide provider of IP-based communications services to businesses and the leading U.S.
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