The data link layer

Skills: noneIT concepts: LAN, medium access, Ethernet and WiFi protocols, why standards win

This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.

• Internet concepts– Applications– Technology (communication)– Implications for

• Internet skills– Application development– Content creation

Where does this topic fit?

TCP/IP protocol layers from 1,000 feet up

Application

Transport

Internet

Data link

Physical

Programs that do useful work like retrieve Web pages, copy files, send and receive email, etc.

Make client-server connections and optionally control transmission speed, check for errors, etc.

Route data between networks

Route data within the local area network

Specify what medium connects two nodes, how binary ones and zeros are differentiated, etc,

The view from 2,000 feet

Networks inside the cloud

The router at the edge of each network

The LANs and the Internet

Data linklayer

Data linklayer

Internet layer

A simple LAN combining data link (Ethernet and WiFi) and internet (IP) protocols in one box

A complex LAN may have many switches and routers

Data link layer protocols

Ethernet (copper and optical fiber)

WiFi (physical and data link)

101011010101010101101010111010101011

101011010101010101101010111010101011

Transfer data and check for errors

Medium access control

WiFi and Ethernet won because they were

Open

Dynamic

(WiFi was also license free)

The data link layer

Skills: noneIT concepts: LAN, medium access, Ethernet and WiFi protocols, why standards win

This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.