Computer Networks Fundamentals

Internet and Network Fundamentals

• The internet is a global network connecting millions of computers to exchange data, news, and documents.
• The internet relies on a physical infrastructure/device to connect networks to other networks.

Computer Networks

• A computer network is a group of two or more computers linked together to exchange information and data.
• Computer networks can also use resources of other computers.
• Basic network components include:
  • Server
  • Client
  • Media
  • Network Adopter (Network Interface Card)
  • Resources
  • User
  • Protocols

Server

• A server is a powerful computer that provides services to other computers on the network.
• The server is in charge of sending programs and files to computers.

Client

• A client is a computer device that accesses and uses the network as well as shares network resources.
• Clients are less powerful than servers and typically do not share their resources.
• Examples of client-server applications include email, network printing, and the World Wide Web.

Media

• Media is the physical connection between devices and computers.
• Examples of media include cables.

Network Adopter (Network Interface Card)

• A Network Interface Card (NIC) is a circuit board that enables sending and receiving data.
• NICs are plugged into a motherboard or PCIe port.

Resources

• Resources include devices such as FAX, printers, and more.
• Any device available to a client on the network is considered a resource.

User

• A user is a person who uses a client to access resources on the network.

Protocols

• Protocols are set of defined rules that allow entities to communicate across computers.
• Examples of protocols include:
  • TCP (Transmission Control Protocol)
  • IP (Internet Protocol)
  • HTTP (Hypertext Transfer Protocol)
  • SMTP (Simple Mail Transfer Protocol)
  • FTP (File Transfer Protocol)
  • SNMP (Simple Network Management Protocol)
  • DNS (Domain Name System)
  • DHCP (Dynamic Host Configuration Protocol)
  • SSH (Secure Shell)
  • BGP (Border Gateway Protocol)
  • VoIP Protocols (SIP, RTP, RTCP)
  • Wireless Protocols (Wi-Fi, Bluetooth, Zigbee)

Basic Types of Computer Networks

Local Area Network (LAN)

• A LAN connects network devices over a relatively short distance.
• It provides a local connection, such as internet cable and wireless access.
• LANs are faster and have less congestion due to the short distance.

Wide Area Network (WAN)

• A WAN provides long-distance transmission of data, voice, image, and video information over large geographical areas.
• Examples of WANs include ZPN and the internet.