Physical Layer - Overview
Includes network hardware and circuits
- physical media (e.g., cables) and
- special purposes devices (e.g., routers and hubs).
Types of Circuits
- Physical circuits connect devices & include actual wires such as twisted pair wires
- Logical circuits refer to the transmission characteristics of the circuit, such as a T-1 connection refers to 1.5 Mbps
- Can be the same or different. For example, in multiplexing, one wire carries several logical circuits