A telecommunications company that offers Toll-Free Services to its customer.

An entity that offers Shared Use Toll-Free Service to its Customers and holds the rights of Toll-Free Subscriber on the Toll-Free Number.

A Toll-Free Service Provider that purchases Toll-Free Service from another Toll-Free Service Provider and resells the Toll-Free Service to it’s customers.

Toll-Free Service that is resold by the customer of a Toll-Free Service Provider to a Toll-Free Subscriber or to another Toll-Free Service Reseller.

An electrically generated single-frequency sinusoidal oscillation. [T1.305-1990]

In a voice frequency telegraph (VFTG) transmission system, the use of two channels to carry the same information.
Note: Tone diversity is usually achieved by twinning the channels of a 16-channel VFTG to obtain 8 channels with dual diversity.

See dual-tone multifrequency signaling.

Synonym utility program.

In Internet addressing, a domain name identifying the highest hierarchical level in the geographical or organizational structure of the addressing system in Internet.
Note: In Internet, the top-level domain name is either an ISO country name, or an English abbreviation such as "com," "edu," "gov," "mil," "net," or "org. " [After 2382-pt.35]

The specification and arrangement in physical locations of actual communication and information system components which implement the topology.