dial-up modem
CCNA
What Is Dial-Up? How Dial-Up Modem Connections Work
Dial-up is a WAN connection technique established using a modem and an active PSTN (Public Switched Telephone Network) line. The modem dials a phone number attached to another modem at the destination end and establishes a connection capable of transferring data, using the ordinary analog telephone line as the transmission medium. Dial-up was, for decades,...
CCNA
WAN Devices: Roles, Verification, and Selection
A WAN connection rarely involves just a router. Between the customer’s equipment and the provider’s core, a small set of specialized devices each handle a distinct job — converting signals, providing clocking, switching carrier traffic, or forwarding at the speeds a provider backbone demands. Knowing what each device actually does, and how to verify it’s...