company, the switchboard attendant can ask where they saw the ad. The receptionist then dials a three-digit code relating to that ad on the touchtone pad on the telephone before sending the caller through to the salesperson. The result- ing report will indicate the volume of calls you are receiving from each ad, helping you to spend your advertising dollars more effectively. Or if you have a group of separate 800 numbers used for different marketing purposes, the Call Accounting system can track call volume by the 800 number called. TRAFFIC STUDIES ON OUTSIDE LINE USE Another function of the Call Accounting system is to track call activity on each of your outside lines, which is known as a traffic study. If you request a traffic study from your telephone installation and maintenance company, there may be a charge of up to $1,500. If you have a Call Accounting system you may do it yourself as often as you wish. This lets you know whether all of your outside lines are in use and if so, how often. If you have 25 outside lines and only 15 are in use at the busiest times of day, you will be able to disconnect some lines to lower your monthly costs. If the traffic study shows that all 25 lines are in use at the busiest times of day, this means that your callers are hearing busy signals when they dial your number, it's time to order more lines. OPTIMIZING YOUR TELECOMMUNICATIONS NETWORK FOR VOICE CALLS Call Accounting reports can also single out calls to a specific telephone number. If you have two offices and you see that you The Telecom Handbook 123 CALL ACCOUNTING & TELEMANAGEMENT SYSTEMS are spending $1,000 monthly to make telephone calls back and forth between them, you may want to order tie lines (can be individual lines or on a T-1 circuit) to connect the offices. This may cost only $400 per month per line (varies widely depending upon the distance) and permits an unlimited amount of calls (one call at a time per line). Rather than ordering a tie line, you may also want to consider sharing of data circuits for in