Definition: end office switch

A telephone central office switch that connects directly to the customer. Also called a "Class 5 switch" or "TDM switch," an end office switch is a computer specialized for TDM-based, circuit-switched telephone calls. It handles services such as call forwarding and call waiting. Such switches are typically from Lucent and Nortel Networks (see ESS and DMS).

Most of the call recording and billing is also performed in Class 5 end office switches, whereas in the past, it was handled in Class 4 tandem switches. Local telephone companies use both end office and tandem switches, which may be the exact same hardware with services differentiated only by software. See tandem switch.