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Module Objectives

  • Module Title: Networking Today
  • Module Objective: Explain the advances in modern technologies.

Topic Objectives

  • Networks Affect our Lives
    • Explain how networks affect our daily lives.
  • Network Components
    • Explain how host and network devices are used.
  • Network Representations and Topologies
    • Explain network representations and how they are used in network topologies.
  • Common Types of Networks
    • Compare the characteristics of common types of networks.
  • Internet Connections
    • Explain how LANs and WANs interconnect to the internet.
  • Reliable Networks
    • Describe the four basic requirements of a reliable network.
  • Network Trends
    • Explain how trends such as BYOD, online collaboration, video, and cloud computing are changing the way we interact.
  • Network Security
    • Identify some basic security threats and solutions for all networks.
  • The IT Professional
    • Explain employment opportunities in the networking field.

1.1 Networks Affect Our Lives

  • Communication is integral to human existence—comparable to air, water, food, and shelter.
  • Networking allows unprecedented connectivity in today's world.

1.2 Network Components

Host Roles

  • Every computer on a network is referred to as a host or end device.
  • Servers provide information to end devices:
    • Email servers
    • Web servers
    • File servers
  • Clients are computers that send requests to servers to retrieve information:
    • Requesting web pages from web servers.
    • Requesting emails from email servers.
Server Types and Descriptions
  • Email Server: Runs email server software; clients access email using client software.
  • Web Server: Runs web server software; clients access web pages using browser software.
  • File Server: Stores corporate/user files; clients access these files as needed.

Peer-to-Peer Networks

  • Devices can act as both client and server in a Peer-to-Peer Network.
  • Advantages:
    • Easy to set up
    • Less complex
    • Lower cost
  • Disadvantages:
    • No centralized administration
    • Less secure
    • Not scalable
    • Typically slower performance
    • Used for simple tasks (file transfer, printer sharing).

End Devices

  • End Device: Source or receiver of a message in a network; data originates from an end device, flows through the network, and arrives at another end device.

Intermediary Network Devices

  • Intermediary Devices: Connect end devices and manage data flow, including:
    • Switches
    • Wireless Access Points
    • Routers
    • Firewalls
    • Functions of intermediary devices include:
    • Regenerating and retransmitting data signals.
    • Maintaining network pathway information.
    • Notifying devices of errors and communication failures.

Network Media

  • Network Media: Medium through which messages travel.
    • Media Types:
    • Metal Wires within Cables: Use electrical impulses.
    • Fiber-Optic Cables: Use pulses of light (made from glass or plastic fibers).
    • Wireless Transmission: Utilizes modulation of electromagnetic waves.

1.3 Network Representations and Topologies

Network Representations

  • Network diagrams (topology diagrams) use symbols to represent devices.
  • Key Terms:
    • Network Interface Card (NIC)
    • Physical Port
    • Interface
    • (Note: Terms port and interface are often interchangeable).

Topology Diagrams

  • Physical Topology Diagrams: Illustrate physical location and cabling.
  • Logical Topology Diagrams: Illustrate devices, ports, and addressing schemes.

1.4 Common Types of Networks

Networks of Many Sizes

  • Small Home Networks: Few computers interconnected.
  • Small Office/Home Office (SOHO): Connects computers to corporate networks.
  • Medium to Large Networks: Hundreds/thousands of interconnections.
  • World Wide Networks: Include countless interconnected devices globally (e.g., the internet).

LANs and WANs

  • Local Area Network (LAN):
    • Covers small geographic area, connects end devices.
  • Wide Area Network (WAN):
    • Covers a wide geographic area, connects multiple LANs.
  • Comparison:
    • LAN: High-speed; single organization administration.
    • WAN: Slower; typically administrated by multiple service providers.

The Internet

  • The internet is a global collection of interconnected LANs and WANs, connected using various transmission mediums (copper wires, fiber optics, etc.).
  • Not owned by any individual/group; managed by entities such as IETF, ICANN, and IAB.

Intranets and Extranets

  • Intranet: Private collection of internal LANs/WANs accessible only to members.
  • Extranet: Provides secure access to authorized individuals from outside organizations.

1.5 Internet Connections

Internet Access Technologies

  • Home/small office services:
    • Broadband Cable, DSL, Wireless WANs, Mobile Services.
  • Organizations require faster connections for IP phones, video conferencing, and data centers, provided by service providers including business DSL, leased lines, and Metro Ethernet.

Home and Small Office Internet Connections

  • Cable: High bandwidth, always-on internet via cable providers.
  • DSL: Similar to cable but over telephone lines.
  • Cellular: Involves cellular networks connected to the internet.
  • Satellite: Benefits rural areas lacking ISPs.
  • Dial-up: Low bandwidth using a modem, cost-effective.

Business Internet Connections

  • Corporate connections need higher bandwidth and dedicated services:
    • Dedicated Leased Lines: Reserved circuits connecting offices.
    • Ethernet WAN: Extends LAN access into WANs.
    • Business DSL: Available in various formats (e.g., Symmetric Digital Subscriber Lines).
    • Satellite: Used where wired options are unfeasible.

The Converging Network

  • Historically, separate wiring was used for voice, video, and data.
  • Converged Networks: Carry multiple services on a single link (data, voice, video) using unified standards and technologies.

1.6 Reliable Networks

Network Architecture

  • Network Architecture: Technologies supporting data movement across networks.
  • Four Basic Characteristics:
    • Fault Tolerance
    • Scalability
    • Quality of Service (QoS)
    • Security

Fault Tolerance

  • Designed to limit failure impact, requiring multiple pathways.
  • Packet Switched Network: Splits traffic into packets, routing through different paths as needed; differs from circuit-switched networks that establish dedicated circuits.

Scalability

  • Scalable networks can quickly and easily expand to support new users/applications without degrading performance.
  • Recommendations for scalability include following accepted standards and protocols.

Quality of Service (QoS)

  • QoS ensures reliable delivery, managing data, voice, and video flows effectively.
  • Mismanaged bandwidth can cause interruptions in live video streams.

Network Security

  • Primary Security Types:
    • Infrastructure Security: Protects devices from unauthorized access.
    • Information Security: Safeguards data transmission.
  • Three Main Goals of Network Security:
    • Confidentiality: Only intended recipients can read data.
    • Integrity: Data remains unaltered during transmission.
    • Availability: Authorized users have reliable access to data.

1.7 Network Trends

Recent Trends

  • The networking role must adjust to new technologies/devices, including:
    • BYOD (Bring Your Own Device)
    • Online Collaboration
    • Video Communications
    • Cloud Computing

Bring Your Own Device (BYOD)

  • BYOD allows users to use personal devices for work purposes, enhancing flexibility.
  • Devices include laptops, tablets, smartphones, and e-readers.

Online Collaboration

  • Enables users to work together over the network on projects.
  • Tools like Cisco WebEx facilitate instant connection and interaction, a priority in business and education.

Video Communication

  • Video conferencing connects users regardless of their location, essential for collaboration.
  • Cisco TelePresence: An example of technology that supports a global workforce model.

Cloud Computing

  • Enables file storage/backup on servers over the internet, accessible globally.
  • Data centers allow smaller companies to lease services from larger entities.
Types of Clouds
  1. Public Clouds: Available for general public; pay-per-use or free.
  2. Private Clouds: Exclusive to specific organizations (e.g., government).
  3. Hybrid Clouds: Combination of two cloud types, connected via unified architecture.
  4. Custom Clouds: Designed to meet industry-specific needs.

Technology Trends in the Home

  • Smart home technology allows appliances to interconnect and communicate, enhancing convenience.

Powerline Networking

  • Allows LAN connection where traditional cabling isn’t feasible by utilizing electrical outlets.

Wireless Broadband

  • Applicable particularly in rural areas, connects homes/businesses through Wireless Internet Service Providers (WISP) using cellular technology.

1.8 Network Security

Security Threats

  • Essential for all network sizes: securing data while maintaining quality of service.
  • Threat Vectors: Can be external or internal.
External Threats
  • Types include:
    • Viruses, worms, Trojan horses
    • Spyware and adware
    • Zero-day attacks
    • Denial of service attacks
    • Identity theft
Internal Threats
  • Types include:
    • Lost or stolen devices
    • Accidental misuse by employees
    • Malicious employees

Security Solutions

  • Security should be multilayered, including:
    • For Home/SOHO Networks:
    • Antivirus/antispyware on end devices.
    • Firewall filtering to block unauthorized access.
    • For Larger Networks:
    • Dedicated firewalls
    • Access Control Lists (ACL)
    • Intrusion Prevention Systems (IPS)
    • Virtual Private Networks (VPN)

1.9 The IT Professional

CCNA Certification

  • The Cisco Certified Network Associate (CCNA) certification validates foundational knowledge in networking, essential for staying relevant.
  • Focus Areas Include:
    • IP foundations and security
    • Wireless technologies
    • Virtualization and automation
    • Network programmability
  • DevNet Certifications: Validate software development skills at various levels to match professional roles.

Module Practice and Quiz

Key Learnings

  • We connect through networks like never before.
  • All computers in a network are classified as hosts.
  • Network diagrams use symbols for easy understanding.
  • LANs and WANs are the two main types of network infrastructures.
  • SOHO and corporate internet connections have distinct types of services.
  • Key characteristics of network architecture include Fault Tolerance, Scalability, QoS, and Security.
  • Networking trends like BYOD, online collaboration, video communications, and cloud computing are significant.
  • Understanding network security threats and solutions is critical for safeguarding data.