ECS Network Study Guide

Networking and Communication Study Guide

Key Terms and Acronyms

  • NIC - Network Interface Card

  • PAN - Personal Area Network

  • MAN - Metropolitan Area Network

  • HTTP - Hypertext Transfer Protocol

  • HTTPS - Hypertext Transfer Protocol Secure

  • VAN - Value-Added Network

  • BPS - Bits Per Second

  • VPN - Virtual Private Network

  • SMTP - Simple Mail Transfer Protocol

  • POP - Post Office Protocol

  • LAN - Local Area Network

  • WAN - Wide Area Network

  • DNS - Domain Name System

  • DHCP - Dynamic Host Configuration Protocol

  • HTML - Hypertext Markup Language

  • NOS - Network Operating System

  • PPP - Point-to-Point Protocol

  • ICMP - Internet Control Message Protocol

  • UDP - User Datagram Protocol

  • RPC - Remote Procedure Call

  • NetBIOS - Network Basic Input/Output System

  • TLS - Transport Layer Security

  • ASCII - American Standard Code for Information Interchange

  • OSI - Open Systems Interconnection

  • NFS - Network File System

  • PDU - Protocol Data Unit

  • VOIP - Voice Over Internet Protocol

  • DSL - Digital Subscriber Line

  • ARP - Address Resolution Protocol

  • SNMP - Simple Network Management Protocol

  • SARP - Scalable Address Resolution Protocol

Networking Concepts

  • Bandwidth: The maximum rate of data transfer across a network path, measured in bps (bits per second).

  • Protocol: A set of rules governing data transmission between devices in a network.

  • Router: A device that forwards data packets between networks, determining the best route for data.

  • Firewall: A security system that monitors and controls incoming/outgoing network traffic.

  • LAN (Local Area Network): A network within a limited geographical area (home, office).

  • WAN (Wide Area Network): A network that connects multiple LANs across larger areas.

  • IP Address: A numerical label assigned to each device in a network for identification and routing.

  • MAC Address: A unique identifier for network interfaces used for communication in a network.

  • DNS (Domain Name System): Translates human-readable domain names into IP addresses.

  • Subnet: A smaller, more manageable segment of a larger network.

  • Gateway: A node that links two different networks.

  • DHCP (Dynamic Host Configuration Protocol): Automatically assigns IP addresses and network parameters to devices.

Network Types and Protocols

  • LAN vs WAN:

    • LAN: Limited geographical area, often faster and more secure (e.g., home network).

    • WAN: Spans large areas, connects multiple LANs, often slower and broader (e.g., the internet).

  • HTTP and HTTPS: Protocols for transferring data over the web. HTTPS encrypts the data for security.

  • SMTP: Used for sending emails between servers.

  • POP3: Retrieves emails from a server.

  • TCP/IP: Foundation of internet protocols, manages connections and data exchange.

  • UDP: A connectionless protocol for faster, but less reliable, data transfer.

  • DNS: Resolves domain names to IP addresses.

  • DHCP: Dynamically assigns IP addresses to network devices.

Network Layers (OSI Model)

  • Physical Layer: Transmits raw data bits over a physical medium (e.g., Ethernet cables).

  • Data Link Layer: Manages data frames, error detection, and access to the physical medium.

  • Network Layer: Handles logical addressing, routing of data packets (e.g., IP).

  • Transport Layer: Ensures reliable end-to-end communication, segments data (e.g., TCP, UDP).

  • Session Layer: Manages communication sessions between applications (e.g., RPC, NFS).

  • Presentation Layer: Formats data for the application layer, includes encryption and compression.

  • Application Layer: Provides network services directly to user applications (e.g., HTTP, FTP, DNS).

Network Topologies

  • Bus Topology: All devices are connected to a single central cable.

    • Advantages: Simple, less cabling.

    • Disadvantages: Troubleshooting difficult, one failure affects all.

  • Star Topology: Devices are connected to a central hub.

    • Advantages: Easy to manage, isolated failures.

    • Disadvantages: More cabling, hub failure affects all.

  • Ring Topology: Devices connected in a circular fashion.

    • Advantages: Equal access, high-speed data travel.

    • Disadvantages: One failure affects all.

  • Hybrid Topology: Combines multiple topologies for flexibility and scalability.

    • Advantages: Customizable.

    • Disadvantages: Complex and costly to implement.

Communications Hardware

  • Router: Routes data between networks

    • Example: Home Wi-Fi router

  • Modem: Connects home network to ISP

    • Example: DSL modem

  • Firewall: Monitors and controls network traffic

    • Example: Hardware firewall

  • Bridge: Connects and filters traffic between network segments

    • Example: Network bridge

  • Gateway: Translates different network protocols

    • Example: VoIP gateway

  • Hub: Connects multiple devices in a network

    • Example: Ethernet hub

  • NIC: Enables sending and receiving data between computers on a network

    • Example: Network Interface Cards

Transmission Media

  • Physical Media: Cables and wires such as twisted-pair, coaxial, fiber-optic cables.

  • Wireless Media: Radio waves, microwaves, and satellite transmission.

Network Management Software

  • Cisco Network Assistant: Software for managing network devices and traffic.

  • Intrusion Detection System (IDS): Monitors for potential security threats in a network.

Key Network Protocols

  • HTTP: Transfers web pages over the internet.

  • HTTPS: Secure version of HTTP, encrypts data.

  • FTP: Transfers files between client and server.

  • SMTP: Used for sending emails.

  • TCP/IP: Core internet protocols for managing data connections.

  • UDP: Faster, connectionless data transfer protocol.

  • DHCP: Assigns dynamic IP addresses to devices on a network.