Foreign Area Translator
A foreign area translator (FAT) is a type of translator that handles area codes in a 5XB completing marker. In 5XB offices for which all foreign area (long distance) traffic is sent to a tandem or toll switch for completion, there is usually no need for a FAT, because all calls out of the local dialing area can indiscriminately be sent onward for completion over a single route. However, in 5XB offices that are near an area code boundary, there may be direct trunks to a nearby office, even if it is technically in an entirely different area code. Thus, routing that traffic off to a long distance switch may not be the best or most direct choice. Foreign Area Translators allow 5XB switches to choose with greater discrimination on routes to nearby switches in other area codes.