Troubleshooting Telephone Problems. First you need to know where the trouble lies. The phone company owns and maintains the telephone lines (wires) that bring phone service to your house. Usually, a gray plastic box is mounted to the side of your house that is split into two parts, the customer and utility connections. Although you can access the customer side of the box, the phone company side has a special screw that doesn't allow customers to remove, nor should you. Often, the company places a demarcation jack that is located either in a basement or utility room wall. To this point, it is the phone company's responsibility to provide service at no charge, if there is a problem. However, if the problem lies after this point, you'll be responsible for technical services if you want their technician to fix a problem within your home. For AVAYA, NORSTAR, NEC, SAMSUNG, MITEL, PANASONIC, TOSHIBA telephone systems and voicemail call (866)206-2316 or email