means of checking the accuracy of their monthly telecommuni- cations bills and the Call Accounting system can help in this effort, few succeed due to not their not being willing to spend enough time to get the call costing right and to keep it accurate. Charging Back the Cost of Outside Lines and the Telephone System Some organizations also charge back the cost of outside lines and the telephone system itself, using the Call Accounting sys- tem. Some simply divide the cost equally among all of the users or departments. Others allocate the cost of these proportionately to the call volume of each department. As with all costing, to do this accurately, the true costs must be known. Toll Fraud Prevention As the incidence of Toll Fraud increases, Call Accounting systems are assuming a renewed importance, since many are sold with Toll Fraud Packages included or optional. Toll Fraud refers to the unauthorized use of your telephone system by outsiders to make long distance calls on your lines. Toll Fraud is a multi- billion dollar illegal industry and all organizations are vulnerable. Your telephone system may be "hacked into" through your 800 (toll free) number, your Voice Mail system or the remote access port used by your telephone installation and maintenance com- pany to diagnose problems. The Toll Fraud package in your Call Accounting system will not prevent this access, but will alert you to unusual calling pat- terns taking place through your telephone system, which may indicate unauthorized use in progress. Some Call Accounting systems dial a beeper number to immediately alert you to a prob- lem. Others simply print a warning on the screen of the system administration terminal or on the paper report. 122 - The Telecom Handbook CHAPTER 6 Other Applications for Call Accounting TRACKING EFFECTIVENESS OF ADVERTISING Although most companies use Call Accounting to obtain ba- sic reports on outgoing calls, others are more creative. For example, if you advertise in several different publications, when someone calls your 