Request Line - Telephone Network

Telephone Network

Although only one telephone number is usually announced, major stations typically have line hunting, with the same number being directed to any available one of several lines within the hunt group. If there are no open lines, the calling party may receive a busy signal as with an ordinary telephone call, or sometimes the special information tones followed by a recorded announcement that "all circuits are busy, please try your call again later". In this case, the line often first gives that caller a ringback tone as if the call were being completed, misleading callers to think they may have actually gotten through the swarm of other calls that sometimes flood these lines.

Within the North American Numbering Plan, telephone companies typically use special numbers for these lines, with a reserved prefix corresponding to high-capacity multi-line numbers instead of to a physical telephone exchange. In Miami, for example, numbers are 305-550-xxxx, while in metro Atlanta they are 404-741-xxxx. The last four digits are usually chosen by the station to be their callsign or frequency, or their moniker if it is short (such as B937 (2937) for a fictional B-93.7 FM).

When used on a radio show or TV show carried on a broadcast network, such a number is usually a toll-free telephone number, without a special number since it simply redirects to a local request line circuit. This allows anyone to call regardless of the location, even from a payphone. Some stations may have vertical service codes for use by mobile telephones. These are also common in the U.S. for TV stations to advertise for gathering news tips from the public, but are often specific to callers on a certain sponsoring mobile telephone company.