Topic 1 Notes

Topic 1: Introduction to Network Design

  • COSC 2385: Networking 1 – Topic 1: Introduction to Network Design (RMIT)

  • Purpose: Build practical and conceptual skills foundational to understanding basic networking.

  • Learning outcomes (high level): Discover media types used to carry data; become familiar with network devices and addressing schemes; understand the impact of networking on daily life; build simple LANs.

Introduction to Networks

  • Communication is almost as important to us as air, water, food, and shelter.

  • In today’s world, people can communicate instantly with each other.

  • Networks and the Internet have changed how we communicate, learn, work, and play.

  • Networks come in all sizes, from two computers to millions of devices.

Network Size Overview

  • The Internet: A global network connecting billions of devices worldwide.

  • Small Home Network: Typically used for personal devices and basic internet access.

  • Medium to Large Network (SOHO): Facilitates larger organizations with extensive connectivity needs; supports small business operations with shared resources.

Network Types

  • Wide Area Network (WAN): Largest network spanning countries or continents.

  • Metropolitan Area Network (MAN): Network covering a city or region.

  • Local Area Network (LAN): Network within a building or campus.

  • Wireless Local Area Network (WLAN): Wireless connectivity in local areas.

  • Personal Area Network (PAN): Smallest network for personal devices.

Rules of Communication

  • The sending of a message is governed by rules called protocols.

  • Protocols are specific to the medium used in communication.

  • All communication methods share three elements:

    • message source, or sender

    • destination

    • a pathway channel (medium)

Users, Clients and Servers in IT Networks

  • Users are devices that communicate, also called hosts or end devices (e.g., PCs, phones, TVs).

  • Servers run software to provide information like web pages, emails, and files (e.g., Web server, DNS server, email server).

  • Clients run software (e.g., Internet Explorer, Safari, Chrome) that requests/displays information from servers.

  • A single host can be both a client and a server.

Basic Network Components

  • Devices: Hardware such as PCs, printers, monitors, routers, switches.

  • Media: Used to transfer data between devices (e.g., Ethernet cables, optical fibre, serial cables, telephone lines, radio waves).

  • Services: Software that runs on networked devices (e.g., email hosting, video).

  • End devices: Computers, network printers, VoIP phones, TelePresence endpoints, security cameras, mobile devices.

  • Intermediary Network Devices: Enable network access (e.g., switches, wireless access points, routers, firewalls).

Network Components & ICONs of Simulated Devices

  • End Devices / hosts

  • Intermediary Devices

  • Network Media

  • Q: What do these devices have in common?

Common Characteristics of Network Devices (and what they have in common)

  • All have:

    • Processing power

    • Memory

    • NICs (Network Interface Cards) – interfaces that enable physical connectivity to the network

  • You’ll learn how components use protocols (a set of rules) to communicate over networks and applications.

  • Networks require documentation of a set of rules in various formats to assist in design, modification, and troubleshooting a network.

Connecting to the Network

  • A physical (wired or wireless) connection to a LAN is needed first.

  • Many homes use a combination of a wired/wireless switch and router called an integrated service router (ISR).

  • Devices are interconnected using media, also called the medium.

Network Medias (Modern IT network medias)

  • Three primary types of media used to interconnect devices and provide pathways for data transmission:

    • Metal wires – Copper cable: electrical pulses

    • Glass or plastic – Fibre/Optical cable: light pulses

    • Wireless: electromagnetic waves

  • All are controlled by standard protocols.

  • Q: Which one is the best choice? (Note: depends on needs; see discussions below)

Copper vs Glass/Plastic (Fiber) vs Copper – UTP, STP (as presented)

  • Glass & Plastic (Fiber) vs Copper (UTP/STP)

    • Fiber: Light pulses; Costly; Long distance; Highest Bandwidth; EMI-free

    • Copper: Electric pulses; Cheaper/common; 100 m distance; PoE; Suffer from EMI; Lightning & cross-talk

    • Note: The slide pairs “Fiber” with high bandwidth and EMI-free and Copper with PoE and EMI susceptibility; Wireless row is not fully detailed here.

  • Related terms to consider: UTP (Unshielded Twisted Pair), STP (Shielded Twisted Pair).

  • See Netacad resources for more info.

Media Characteristics: Copper, Fiber, and Wireless (summary cues from slides)

  • Copper Cable

    • Bandwidth: High (relative to older copper spec) – typical capabilities depend on standard used (e.g., Cat5e/Cat6).

    • Distance: Limited to about 100 m for Ethernet without repeaters.

    • Installation cost: Higher than wireless; PoE capability often available.

    • Security/Interference: Susceptible to EMI and cross-talk; Lightning risks exist.

  • Fiber-Optic Cable

    • Bandwidth: Very high; often described as high bandwidth capacity (as per slide’s phrasing).

    • Distance: Very long-distance transmission with minimal signal loss.

    • Installation cost: Higher due to equipment and installation complexity.

    • EMI: Free from EMI; more secure against tapping.

  • Wireless

    • Media: Electromagnetic waves; no physical cables.

    • Flexibility: Highly flexible and convenient.

    • Security/Interference: Susceptible to interference and security risks.

Which network media is most suitable for specific needs?

  • Fiber-Optic Cable: High bandwidth and security, but costly and complex installation.

  • Copper Cable: Cost-effective and easy to install, but limited bandwidth and distance.

  • Wireless Communication: Flexible and convenient, but susceptible to interference and security risks.

Network Trends

  • Networks must continually transform to keep up with new technologies and end-user devices.

  • Trends affecting organizations and consumers:

    • Bring Your Own Device (BYOD)

    • Online collaboration

    • Video communications

    • Cloud computing

Device Interface

  • An interface is a link to plug and play a device to access the device.

  • Example interfaces:

    • Router: Gig0/0 and Gig0/1

    • Switch: Fa0/1, Fa0/2, Fa0/3

    • PCs: Fa0 (one interface each)

  • Important note: Addresses should be assigned to all used interfaces; all addresses are paired with a subnet mask.

Topic Summary

  • Networks and the Internet have a dramatic impact on our lives.

  • A network can be as small as two devices or as large as the Internet with millions of devices.

  • Using appropriate media for a network is important.

  • Network components use protocols to communicate over networks and applications.

  • Recent networking trends affecting organizations and consumers: BYOD, online collaboration, video communications, cloud computing.

  • Network diagrams often use symbols to represent devices and connections.

New Terms and Commands (Glossary Overview)

  • Protocols, Media/Medium, Copper, Fibre-Optic, EMI, Cross-talk, Light pulses, Electric pulses, Electromagnetic waves

  • End Devices, Intermediary Devices, Hosts, Routers, Switches, ISR, Interface

  • Users, Servers, Clients, Services

Next Topic

  • Topic 2: Network Models and Introduction to Wireless Technology

  • Advice: It is essential to grasp Topic 1 and go through next week’s lecture notes before the next session.