Unit 5 Flashcards
Fibre Optic Backbone
Definition:
A high-speed network connection that connects different parts of a network, allowing information to be exchanged between various points.
Uses:
Connects large networks within the same building, across different buildings in a campus, or over wide areas.
Advantages:
Preferred for its speed and reliability.
WAN (Wide Area Network)
network that is not limited to one area and can be owned by multiple organizations.
Comparison: Unlike a LAN (Local Area Network), which is limited to a small area and owned by a single organization, a WAN spans broader geographical areas.
Gateways
Definition:
A device that connects and allows communication between two or more network segments.
Functionality:
Operates at any network layer, usually between different protocols.
Router Capabilities
Functionality:
A router can see both MAC and IP addresses of the data.
Limitation:
It cannot repackage packets and frames for a different protocol.
Example:
If one network uses TCP/IP and another uses a different protocol, a gateway would be required to facilitate communication between them.
Satellite Radio Waves (5.4.1)
Definition:
Satellite communication uses satellites for voice/video calling, Internet, TV, radio, and navigation.
Features:
Global coverage, including at sea.
Reliable and secure, used by the military.
High data transmission capacity.
Can function under conditions that
Microwave Communication
Definition:
A microwave link is a communication system that uses microwave frequency radio waves to transmit data, video, or audio.
Range:
Can span distances from a few meters to several kilometers.
Usage:
Often used to connect remote locations or transmit signals where cables cannot be used.
Cellular Technologies
Definition:
Cellular technology underlies mobile phone networks, creating coverage areas called “cells” that overlap to provide broad coverage.
Functionality:
Mobile devices connect to the nearest or least congested base station (cell tower).
As users move, connections are handed over to the next cell tower without losing connection.
3G
“G” stands for “generation.” 3G is the third generation of mobile data technology.
Advancement:
Replaced 2G, which handled basic calls, texts, and minimal data.
3G supports larger data formats like HTML pages, videos, and music, but speeds are relatively slow.
4G
Advancement:
4G provides faster speeds and supports digital media on mobile devices.
Features:
Enables streaming video, rich multimedia apps, and high-quality music with minimal buffering.
Users can experience faster load times and better overall performance compared to 3G.
5G
Key Features:
5G is significantly faster, smarter, and more efficient than 4G.
Performance:
Speeds up to 100 gigabits per second, potentially 100 times faster than 4G.
Low latency (delay), allowing for quicker downloads/uploads and immediate video playback without buffering.
Wi-Fi Calling
Definition:
Wi-Fi calling allows you to make phone calls over the Internet without additional cost beyond data usage.
Use Case:
Useful when connected to Wi-Fi but unable to access the mobile network.
Utilized by apps like FaceTime, WhatsApp, and Facebook.
Fibre
Definition:
Fibre optic cables transmit data with minimal signal loss over long distances.
Advantage:
Offers faster, more reliable Internet connections compared to other technologies like ADSL.
ADSL
Definition:
ADSL uses copper telephone lines to transmit data from your nearest telephone exchange to your location.
Limitation:
Speed decreases the further you are from the exchange.
ADSL is being phased out in favor of faster fibre connections.
Bandwidth
Bandwidth:
The amount of data that can be transmitted from one point to another within a specific time frame.
Internet Speed:
Refers to how fast data travels from the web to your device.
Measured in megabits per second (Mbps).
ADSL Bandwidth
ADSL Overview:
Utilizes copper telephone lines to transmit data.
Distance from the exchange impacts speed—further distance means slower speeds.
ADSL is prone to bottlenecks: more internet traffic slows down speeds, similar to road traffic.
ADSL Speeds:
Offers speeds from 1Mbps up to 40Mbps.
Suitable for basic internet activities like browsing and email.
Fibre Bandwidth
Fibre Internet:
Uses fibre optic cables for data transmission.
Data travels at the speed of light and isn’t affected by distance from the exchange.
Can handle higher volumes of traffic without affecting download speeds.
Advantages:
Provides the fastest speeds, ideal for streaming, online gaming, and large user environments.
Often cheaper than ADSL.
Beneficial for businesses relying on online/cloud-based work.
Email Protocols
SMTP (5.6.1.1):
Simple Mail Transfer Protocol.
Used for sending emails from a client to a server or between servers.
Operates on port 25.
POP3 (5.6.1.2):
Post Office Protocol version 3.
Downloads emails from a server to a client, then deletes them from the server.
Operates on port 110.
IMAP (5.6.1.3):
Internet Message Access Protocol.
Allows emails to be stored on the server, enabling access from multiple devices.
Uses more disk space and CPU resources.
Operates on port 143.
Web Protocols Overview
A set of rules that enable connection, communication, and data transfer between two places on a network.
Key Web Protocol
HTTP:
Standard protocol for transferring web pages across the Internet.
Web addresses typically begin with “http://”.
Most web traffic defaults to using HTTP.
