Feature group

A Feature Group, in North American telephone industry jargon, is most commonly used to designate various standard means of access by callers to competitive long distance services.

They defined switching arrangements from local exchange carriers central offices to interexchange carriers. These arrangements were described in an official tariff of the National Exchange Carrier Association, filed with the Federal Communications Commission (FCC).

While there are other feature groups for local access, the four common feature groups exist for access from the local subscriber to competitive long-distance carriers:

These Feature Group alternatives allowed the LEC's end users to make long distance calls using the interexchange carrier's network, when non-stored program-controlled exchanges could not be modified to provide equal access. By the mid 1990s, Equal Access features in exchange software had rendered Feature Group D universally available in modern landline exchanges; the others are either used for calling card applications or are obsolete.