Computer Networking Part 1

Computing Essentials

Lesson 4:

Computer Networking

​Lesson Objectives

• ​Define computer network

• ​Compare and contrast LANs, WANs, MANs, and VPNs

• ​Distinguish between Internet and Intranet

• ​Describe various network topologies

  • ​Bus, Star, Ring, & Mesh

Computer Network

• ​2 or more computers (or network devices) connected form a network

• ​Enables us to share files, printers, email, and many other resources

• ​Examples of devices include: computers, laptops, phones, printers, scanners, routers, servers, and so much more.

​Local Area Network (LAN)

• ​A group of connected computers within a small geographic area

• ​Range in size and scale based on use

  • ​home network

  • ​school network

  • ​small office network

• ​Wireless LANs (WLANs) extend a LAN to provide wireless connection

​Metropolitan Area Network (MAN)

• ​a network that operates within a large city or multiple small cities (AKA Metro area)

• ​much larger than a LAN because it covers a larger geographic area

• ​typically operated by local governments or private companies

​Wide Area Network (WAN)

• ​The largest network type

• ​Connects 2 or more LANs together

• ​Owned and maintained by the owner of the LANs it connects

• ​The largest WAN in the world is The Internet

Multiple Choice

A network connection across a city

• MAN

• LAN

• Network

• WAN

Multiple Choice

2 or more LANs connected together

• network

• WAN

• MAN

• CAN

Multiple Choice

A group of computers connected in a small geographic area

• LAN

• CAN

• MAN

• WA

​Intranets & Extranets

​There are also networks that are designed to keep information safe from people outside of an organization.

​

• ​Intranet - "I" for Internal

• ​Extranet - "E" for External

Intranet

• ​behind a company firewall (restricted access)

• ​content and files are only accessible by company employees granted permission

• ​Company: calendars, photos, projects, news, groups, etc

​Extranet

• ​very similar to intranet, but can be accessed from outside the physical location of the organization.

• ​usually requires login/password

​Virtual Private Network (VPN)

• ​Secure network connection that allows access to a private network across a public network (such as The Internet)

• ​Secure "tunnel"

• ​Users get a special username & password to access company resources remotely

• ​Enables employees to work from home, grant contractor access, etc

​Key Terms to add to Google Site Notes:

• ​Computer Network

• ​Local Area Network (LAN)

• ​Metropolitan Area Network (MAN)

• ​Wide Area Network (WAN)

• ​Intranet

• ​Extranet

• ​Virtual Private Network (VPN)

• ​Network Topologies: Bus, Star, Ring, & Mesh

Multiple Choice

Provides a secure connection ("tunnel") to a private network ACROSS a public network

• intranet

• VPN

• LAN

• Super Secure Ninja Private Network Protocol

​Network Topologies

​The way a network uses a PHYSICAL layout scheme tells us what type of NETWORK TOPOLOGY it is using.

​

​Each topology has a different and unique purpose for the sharing information across the network.

• ​Bus

• ​Star

• ​Ring (aka Token Ring)

• ​Mesh

​BUS Topology

• ​Connects devices through ONE (1) physical line

• ​Information can flow in only 1 direction

• ​Only 1 computer can send data at a time

• ​Requires a "terminator" at the end of the cable

• ​If the cable fails, the entire network goes down

​STAR Topology

• ​Each computer/device connects to one (1) network device

• ​Network device receives info and transmits it accordingly

• ​High speeds because computers can communicate simultaneously

• ​If one (1) cable fails, most of the network keeps running

• ​Most common topology today

​RING (aka Token Ring) Topology

• ​Connects all computers through one (1) single line

• ​Only one (1) computer can send data at a time

• ​Computer must possess a "token" to send data

• ​"Token" is passed clockwise

• ​If main cable fails, entire network goes down

​MESH Topology

• ​Each computer has a DEDICATED connection to EVERY OTHER COMPUTER.

• ​If one cable fails, the entire network is still running

• ​Most secure and reliable

• ​Most expensive topology due to the amount of cable required

Multiple Choice

What is the most commonly used network topology today?

• Bus

• Star

• Ring (aka Token Ring)

• Mesh

Multiple Select

Which topologies connect through one (1) single line/cable?

• Bus

• Star

• Ring

• Mesh

Multiple Choice

What is the most expensive and most secure topology?

• Bus

• Star

• Ring

• Mesh

Multiple Choice

Which topology passes a toekn clockwise?

• Bus

• Star

• Ring

• Mesh