An Interexchange Carrier (IXC) is a telecommunication company that offers connections between local exchanges in various geographic areas. IXCs are generally referred to as long distance carriers.
Interexchange Carrier is a U.S. legal and regulatory term commonly used by telecommunication companies for long distance telephone companies. IXCs offer local access and transport area services in accordance to the Telecommunication Act of 1996.
An IXC is often defined as a carrier that provides inter-LATA communication, where LATA stands for local access and transport area. From a telephone user’s point of view, a long-distance company does not manage calls that do not have supplementary tolls. Calls made across telephone circuits within a local geographic area covered by a local network are managed only by that one LATA, which is commonly called a local telephone exchange. Local calls are typically described as connections made without additional charge regardless of the fact whether the connected call is in the same LATA or connects to another LATA. The term “Inter-LATA” typically refers to rated or toll calls between LATA in the interior of state boundaries.
An IXC transmit traffic, typically voice traffic, between different telephone exchanges. Usually, different exchanges cover different geographic locations which are connected as distinct central offices (Cos). Central offices are also known as wire centers.
Initially, IXCs carried voice traffic on analog lines. In recent times, voice traffic has become largely digitalized. Now it is more of a data stream that can be blended with data traffic like uplinks for Digital Subscriber Line (DSL). Generally, links between IXCs and COs are Asynchronous Transfer Mode (ATM) links, which are carried on optical fiber.
For voice traffic transmission, IXCs use Soft switches, software code, which applies Session Initiation Protocol (SIP) and error correction.