A ghost call is a telephone call for which, when the recipient of the call answers, there is no one on the other end of the call. The term is also used in managing IP PBX systems. Ghost calls on the lines that cannot be explained or are some residual output of one Real-time Transport Protocol or RTP stream interacting with the PBX.
Contents
Causes
This is generally caused by a neglected Autodialer or indirectly through consequences of restrictions applied to autodialers used for telemarketing by the FCC that restricts how long they can tie up a phone line without causing inconvenience to the receiver or blocking emergency services. It could also fall under the accidental Pocket dialing category.
Consequences
A ghost call sometimes can be repetitive or completely tie up a phone line making it impossible to call 911 in an emergency. You may receive a ghost call sometimes once an hour, once a day or once a week. At a certain level when an Autodialer is completely overlooked and unmanaged or in extremely rare cases where a company goes under and an autodialer gets left running for years before it's discovered, this can be especially annoying as there is no one to complain to.
Stopping the calls
Several websites collect reports of ghost calls. Repeated reports of the same number provide insight into where the machine is located and hopefully aid in getting it shut down (especially the abandoned ones.)
Improvements
Today's autodialer supposedly runs a smarter batch of software, claiming less than a 2% hangup rate. Most telemarketing companies place thousands of calls an hour, bringing that 2% back up to an annoying level however.
In fiction
Ray Bradbury had at one time written a story about a telephone switch box that gained sentience. Its first order of business in the world, stalking. Eventually the person documenting the calls traced it down to a specific phone box and was summarily executed by said box through electrocution.