ARS definition by American Heritage Dictionary
ars - Computer Definition
Also known as Least Cost Routing (LCR). An optional, programmable PBX software feature that enables the system to route a call over the most appropriate carrier and service offering based on factors such as the type of call (e.g., local, local long distance, or long-haul long distance), the Class of Service (CoS) of the user, the time of day (e.g., prime time and non prime time), and the day of the year (e.g., weekday, weekend day, or holiday). In countries where there are lower rates for cellular-to-cellular calls than for calls between cellular phones and landlines, ARS sometimes is used to route the landline leg through a cellular interface to take advantage of the lower rates. ARS is of greatest value if the telecom environment is liberalized or deregulated and there are multiple competing carriers and rate plans from which to choose. In practice, ARS generally is on the basis of a table lookup rather than a hierarchical parsing of a dialed telephone number and calculation of a least cost route. See also carrier, cellular radio, CoS, landline, local long distance, long distance, parse, PBX, and software.