What is ARS?
ARS or Alternate Route Selection is a method of intelligently routing calls, most commonly off-network (i.e., to a number that is not programmed on the local phone system.) Nortel Alternate Route Selection comes in two flavors, the “Basic Alternate Route Selection” (i.e., BARS) and “Network Alternate Route Selection” (i.e., NARS).
Why do I need ARS?
Historically, the public telephone infrastructure was not as robust as it is today and the cost associated with making calls varied not only by the distance from calling party to called party, but also by the time of day. In order for electronic phone systems to intelligently route calls to their destination based on a variety of criteria (e.g., is the user allowed to make long distance calls, are they allowed to make long distance calls to a specific region, are they allowed to make long distance calls during a certain time of day, are they allowed to use more expensive routes as overflow if the least expensive routes are in use, etc.) Nortel created the ARS translators.
Why do I needs two different ARS methods?
BARS and NARS are (for the most part) two different ways of doing the same thing. Traditionally, BARS performs call routing from a phone set on a Nortel phone system to a public telephone number, while NARS performs call routing from a phone set on a Nortel phone system to a number on a private telephone network. If you read the Nortel Technical Publications, the traditional usage is reversed from the documentation (where Nortel recommends routing private network traffic using BARS and routing public telephone network using NARS.)
- ARS 101 (in progress)
- ARS 201 (planned)
- ARS 301 (planned)