Physical Layer Protocols and Services:
L1 controls how data is placed on the media.
It has to encode bits into signals and Tx/Rx these signals across the physical media.
The delivery of frames across media requires.
Physical media and connectors.
A representation of bits – code.
Encoding of data and control information.
Tx and Rx circuitry on devices.
The purpose of L1 is to create the electrical, optical, or radio signal that reqresents the bits in each frame.
It also must retrieve signals from media, restore them to bit representations, and pass them to L2 as a complete frame.
The type of signal – depends on the type of media.
Copper = electrical pulses.
Fiber = patterns of light.
Wireless = patterns of radio transmissions.
Tags: wan, 802.1q, guides, cisco, vlan, router
