Nortel T7100 Phone Charcoal Business Series Terminal Nortel T7100 is simply designed for low traffic areas such as lobbies, office kitchens, reception rooms and break rooms. Although it has only one programmable button it supports a wide range of features. The T7100 is a robust entry level digital phone with one line. It is easy to use and has a great range of features including a 16 char LCD display screen, memory buttons and audio volume controls.