Call completion is a
telephony
Telephony ( ) is the field of technology involving the development, application, and deployment of telecommunication services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is i ...
feature allowing some form of alternative interaction between parties who cannot converse directly with each other.
There are several possible factors which can prevent a
telephone call
A telephone call is a connection over a telephone network between the called party and the calling party.
First telephone call
The first telephone call was made on March 10, 1876, by Alexander Graham Bell. Bell demonstrated his ability to " ...
from connecting successfully:
*
Called party
The called party (in some contexts called the "B-Number") is a person who (or device that) answers a telephone call. The person who (or device that) initiates a telephone call is the calling party.
In some situations, the called party may number m ...
does not answer
* Called party is busy in another call
* Called party is off-line or unavailable
* Called party actively disconnects the call before answering
There are various definitions as to what exactly constitutes call completion.
Generally speaking, call completion may encompass the following services:
*
Voicemail
A voicemail system (also known as voice message or voice bank) is a computer-based system that allows users and subscribers to exchange personal voice messages; to select and deliver voice information; and to process transactions relating to ind ...
*
Call transfer
A call transfer is a telecommunications mechanism that enables a user to relocate an existing telephone call to another phone or attendant console, using a transfer button or a switchhook flash and dialing the required location. The transferred c ...
*
Call waiting
Call waiting is a telephone service where a subscriber can accept a second incoming telephone call by placing an in-progress call on hold—and may also switch between calls. With some providers it can be combined with additional features such ...
*
Messaging
A message is a discrete unit of communication intended by the source for consumption by some recipient or group of recipients. A message may be delivered by various means, including courier, telegraphy, carrier pigeon and electronic bus ...
(e.g. SMS, IM)
*
Presence notification
*
Call queueing
Call or Calls may refer to:
Arts, entertainment, and media Games
* Call, a type of betting in poker
* Call, in the game of contract bridge, a bid, pass, double, or redouble in the bidding stage
Music and dance
* Call (band), from Lahore, Pak ...
*
Automatic redial
*
Text to speech
Speech synthesis is the artificial production of human speech. A computer system used for this purpose is called a speech synthesizer, and can be implemented in software or hardware products. A text-to-speech (TTS) system converts normal languag ...
interaction
The rationale for providing these features is that allowing some sort of communication between parties unable to talk directly serves both the interests of the callers (allowing them to exchange information despite the inability to talk) as well as the
telecommunication
Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than tha ...
operators, as the service allows them to get some return for providing the resources for the call (whereas if the caller simply hangs up, the operators basically have provided the call resources with no return).
Call completion features can be implemented on a
private branch exchange
A business telephone system is a multiline telephone system typically used in business environments, encompassing systems ranging in technology from the key telephone system (KTS) to the private branch exchange (PBX).
A business telephone syst ...
(PBX) (e.g. call hold or call transfer), on a dedicated server (e.g. a voicemail server)
or directly on the client device (e.g. messaging applications).
There are several commercial companies which provide call completion features, as well as IETF documents specifying call completion features for open standards, such as
Session Initiation Protocol
The Session Initiation Protocol (SIP) is a signaling protocol used for initiating, maintaining, and terminating communication sessions that include voice, video and messaging applications. SIP is used in Internet telephony, in private IP telep ...
(SIP).
See also
*
Call termination
References
{{Reflist
External links
Completion of Calls for the Session Initiation Protocol (SIP)-- the IETF VoIP features
IETF Call Completion PPT Call Completion on Ericsson website Article about tips
Telephone service enhanced features
Calling features