Call-back The process when a computer or device calls back an Internet service provider (ISP) to answer a ‘call’ from the ISP alerting the device of incoming traffic from the Internet. The facility can also be used to enhance security on networks: Call-back can ensure that only authorised users are granted network access. A telephony analogy can be used to illustrate how the call-back facility can enhance security: a user requests access to a network by calling the network’s server and stating a username and password. Upon answering the call and hearing the username and password, the network’s server puts the receiver down, then calls the user’s registered telephone number back, this way ensuring that a bogus caller will not get network access. Thus, if an unauthorised person discovers a password and uses it to seek access, access will not be granted as the call-back will go to the registered number of the password’s rightful owner instead. Call-back may, of course, also have implications on which party pays for the ‘call’.
