install cable for your computer network. It does not make sense to have two separate companies (one for tele- phones and one for computers) running cable back to a central point since a significant portion of the cost is for labor. The Telecom Handbook to 283 UNDERSTANDING THE INDUSTRY They will program the system in a manner to complement your organization's particular way of operating. Program- ming the telephone system for the way in which it will be used is as important as buying the right system. Most tele- phone systems have a set of rules determining how they may be programmed. Programming determines such things as which extensions are picked up by which telephones and what happens to a call when it rings on an extension which is unanswered or busy. The interaction between the telephone system and the voice mail system is a key ele- ment of system programming and how successfully your system handles callers. They will train your staff how to use the telephone system and provide an instruction manual. They will handle changes to your system such as installing new telephones, rearranging telephones and making program- ming changes. If you wish, someone on your staff can learn to make some of the system program changes with a Mainte- nance Administration Terminal or MAT. The changes made with the MAT are often called MAC work which stands for moves and changes. They will handle all repairs to the telephone system and the cabling. They may act on your behalf to interface with the local telephone company. If there is a problem with one of your outside lines, they will report the problem and follow up un- til it is resolved. They sell other related systems such as Voice Mail, Auto- mated Attendant and Call Accounting which they will install and maintain. They may also be authorized representatives for a local tele- phone company or a long distance carrier, from whom they 284 ** The Telecom Handbook CHAPTER 13 receive a commission for selling certain types of services. This is called being an Authorized Agent or 