'''Automatic ring back''' is a service offered by phone companies.

On making a telephone call to a number that is engaged, automatic ring back is a service provided by the telephone company whereby, when the called number becomes available, the caller is rung back, usually with a distinctive "ring back" ring. When the phone is picked up, it calls the previously engaged number. The service is typically invoked by keying a number on hearing the engaged tone.

In the UK the service is also known as '''Ringback'''.<ref>[http://bt.custhelp.com/app/answers/detail/a_id/8460/ BT Ringback]</ref>

In the United States the service is often called '''Auto Redial'''.

In the United States Army on post wide communications networks, this is referred to as Callback or Automatic Callback.

==See also== * Callback * Camp-on busy signal * Vertical service code

==References== {{reflist}}

{{refimprove|date=February 2008}}

Category:Calling features

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