callback

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callback

(programming)
A scheme used in event-driven programs where the program registers a subroutine (a "callback handler") to handle a certain event. The program does not call the handler directly but when the event occurs, the run-time system calls the handler, usually passing it arguments to describe the event.

callback

(communications, security)
A user authentication scheme used by some computers running dial-up services. The user dials in to the computer and gives his user name and password. The computer then hangs up the connection and uses an auto-dial modem to call back to the user's registered telephone number. Thus, if an unauthorised person discovers a user's password, the callback will go, not to him, but to the owner of that login who will then know that his account is under attack.

However, some PABXs can be fooled into thinking that the caller has hung up by sending them a dial tone. When the computer tries to call out on the same line it is not actually dialing through to the authorised user but is still connected to the original caller.

callback

(communications)

callback

An authentication technique that calls the sender back. After connection is made, the receiving side breaks the connection and calls the sender to ensure that the logon was made from the authorized computer. Callback prevents a stolen ID and password from being used on a different machine. See also Web callback.
References in periodicals archive ?
Since making that decision, the call center environment is completely improved, she adds, "because customers are delighted and in a much better mood when we reach them." Fonolo's own research has found that 63 percent of consumers prefer the option of a call-back over waiting on hold, and 75 percent say it is "highly appealing."
With real time call-backs, there is no delay in answering the visitor's queries.
In response to Parliament's concerns, Internal Market Commissioner Frits Bolkestein said he supported including a "call-back" provision in the EU Treaty.
It's now possible to restrict access to data bases by controlling terminal use (through call-back systems) and to effectively protect data in transmission through the use of encryption/decryption devices.
The initial installation is expected to reduce hold times, eliminate the need for customers to repeat information after arriving at a live customer care representative and lets customers schedule a 'call-back' at a convenient time.
Patients were yesterday told they will have to wait 16 months for the emergency hotline's call-back service to reach "manageable levels".
THE Coventry branch of Cats Protection has introduced a new helpline call-back service.
This follows the rejection by EU leaders at the Stockholm Summit (23-24 March) of the Parliament's demand for a 'call-back' procedure (see European Report Nos 2580 and No 2577) as a way of implementing financial services legislation.Members of the European Parliament voted by 362 to 23 with 23 abstentions in support of the Resolution.
Police dialled 1471 to catch a killer who had used the same BT call-back service to track his victim, a court heard yesterday.
BlackBerry users can download the free One4000 call-back application to initiate calls via the Internet.
The latest average call-back time for help is 68 minutes - compared with eight minutes when the helpline started in 2002.
When the plenary session at the European Parliament tackles the issue, a vote will be taken on a "call-back" procedure that allows the Parliament to review any proposals made by the Commission."There is a compressed and tight schedule for the discussions with regard to the report", said a Swedish representative.