Lecture Notes: Introduction to Computer Networking

Overview of Introductory Material

• Lecture Goals:
  • Provide a broad overview of computer networking.
  • Introduce key vocabulary.
  • Focus on the big picture; details will be covered later.

Introduction to the Internet and Protocols

• Key Questions:
  • What is the Internet?
  • What is a protocol?
• Lecture Structure:
  • Start with the network edge: hosts, access network, and physical media.
  • Discuss the network core: circuit and packet switching, routers, and switches.
  • Explore network performance, including packet loss and throughput.
  • Introduction to protocol layers and network security.
  • Brief history of computer networks.

What is the Internet?

• Nuts and Bolts Approach:

  • Components: Devices at the edge (hosts/end systems) and network devices (packet switches).
  • Types of packet switches: routers and switches.
  • Communication links interconnect all devices.
  • The Internet is a network of networks, each owned and operated independently.
  • Protocols control data exchange within the network.
  • Internet standards defined by the Internet Engineering Task Force (IETF) as RFCs (Requests for Comments).

• Service Perspective:

  • Internet as a platform for applications, enabling information exchange between endpoints.
  • Complexity of applications built on top of a basic service infrastructure to deliver packets.

What is a Protocol?

• Human Protocol Analogy:

  • Example: "What time is it?" protocol involves a request and a reply.
  • "Question asking protocol" in a classroom setting.
  • Common elements: specific messages and actions taken upon receipt.

• Network Protocols:

  • Analogous to human protocols but involve network components (applications, hosts, routers, switches).
  • Define format and order of messages exchanged and actions taken.

Conclusion

• Summary:
  • Introduction covered a broad overview of what the Internet is and the concept of protocols.
  • Next section will delve deeper into the Internet's structure, starting with the edge devices and working inward.