Network Fundamentals Notes

Networks Overview

  • Networks connect devices, enabling data flow.

  • They include wireless (Wi-Fi, cellular) and wired (Ethernet, fiber optic) connections.

  • Networks are not limited to computers or the Internet.

Personal Area Network (PAN)

  • Example: Smartwatch communicating with smartphone via Bluetooth.

  • Characterized by proximity (e.g., wrist and cell phone).

Local Area Network (LAN)

  • Example: Home Wi-Fi network connecting tablet to the Internet via a wireless access point.

Network Components

  • Desktop computer connects to a switch.

  • Switch connects to a router.

  • Router connects to a modem.

  • Modem connects to the Internet.

  • These components demonstrate the diversity and complexity of even basic network architectures.

Network Convergence

  • Previously, distinct networks served different purposes (analog telephone, digital data, video).

  • Modern networks are unified, carrying voice, data, and video over a single connection.

  • Smartphones exemplify this, treating everything as digital data.

High Availability and Uptime

  • Essential considerations for network design due to heavy reliance on networks.

  • Customers may expect 100% uptime, which is unrealistic.

Service Level Agreement (SLA)

  • Publishes a service level agreement goal - often 99.999% uptime.

  • 99.999% uptime, also known as “the five nines of availability.”

  • Allows only about five minutes of downtime per year.

  • Formula: Availability=Total UptimeTotal TimeAvailability = \frac{Total\,Uptime}{Total\,Time}

Network Technician/Administrator Challenges

  • Maintaining continuous operations (high availability) day after day and year after year.

  • Requires understanding network fundamentals and troubleshooting skills.

Converged Network Designs

  • Support diverse activities like file sharing, video chatting (Zoom, FaceTime), browsing (Google, deontrain.com), and social media (LinkedIn, Facebook, TikTok).

  • Streaming videos (YouTube, Disney+, Netflix).

  • All activities use the same Internet connection because everything is treated as packets inside an IP network.

Ongoing Challenges

  • Supporting an ever-growing range of network traffic.

  • Maintaining the “five nines of availability”.

Course Focus

  • Domain 1: Networking Concepts

  • Domain 2: Network Implementation

Course Objectives

  • Objective 1.2: Compare and contrast networking appliances, applications, and functions.

  • Objective 1.6: Compare and contrast network topologies, architecture, and types.

  • Objective 2.3: Given a scenario, select and configure wireless devices and technologies.

Network Components (Detailed List)

  • Clients

  • Servers

  • Hubs

  • Switches

  • Wireless Access Points

  • Routers

  • Firewalls

  • Load Balancers

  • Proxies

  • Intrusion Detection Systems (IDS)

  • Intrusion Prevention Systems (IPS)

Network Resources

  • Client-server model

  • Peer-to-peer model

Network Geography

  • Personal Area Network (PAN)

  • Local Area Network (LAN)

  • Campus Area Network (CAN)

  • Metropolitan Area Network (MAN)

  • Wide Area Network (WAN)

  • Considerations: Size, scope, and appropriate use cases.

  • Real-world demonstration: How these networks are used in modern vehicles.

Wired Network Topologies

  • Point-to-point

  • Ring

  • Bus

  • Star

  • Hub and spoke

  • Mesh

Wireless Network Topologies

  • Ad hoc

  • Point-to-point

  • Infrastructure mode

  • Wireless mesh networks

Data Center Topologies

  • Three-tier model

  • Collapsed core model

  • Spine and leaf

Data Center Traffic

  • Classification of traffic as it enters, leaves, or transmits throughout data centers.

Assessment

  • A short quiz to assess learning.

  • Review answers to understand correct and incorrect choices.