Phone Switches

Telephone switches route calls through the PSTN (Public Switched Telephone Network).

When you pick up the handset on your home telephone, you are initiating a connection with your local telephone switch. When you dial a telephone number, your phone switch interprets the digits you dial and determines where to route your call.

If your call is to another number in the same area, your local end-office switch will make the call itself. If your call is to another area, your local end-office switch will route your call to a toll-switch. That toll switch will then route your call either to another toll switch or to an end-office switch. When your call is finally routed to an end-office switch, the phone line of your called party will ring.

Telephone switches in use include: