Networks

Networks

1. Types of network

   • WAN
     • Wide Area Network
       • • The computers are wide apart
   • LAN
     • Local Area network
       • • The computers are located at a single site

2. Factors that affect the performance of networks

   • Bandwidth. Throughput. Latency. Jitter. Error rate. Interplay of factors. Satellite telephony. Deep space communication

3. Peer-to-peer + pros and cons

4. Client server + pros and cons

5. Hardware

   • WAP
     • A Wireless Access Point is a switch that allows devices to connect wirelessly
   • Router
     • transmit data between networks e.g. LAN & WAN (The internet). They direct (‘route’) packets of data to their correct destination. They are used in homes and offices to connect LANs to the internet
   • Switch
     • connect devices on a LAN. They receive data and forward it onto the correct device.
   • NIC
     • Network Interface Card
   • Transmission media
     • Wireless + pros and cons
     • Ethernet + pros and cons
     • Wi-Fi
       • Frequencies
         • 2.4 GHZ / 5GHZ
       • Channels
         • 1-12
       • Encryption
         • Data is encrypted before transmission and decoded afterwards

6. Virtual networks & why they are used

   • A virtual network is one that is created through software as opposed to hardware
   • • Reduces network traffic because data will only be sent to members of the VLAN
   • • Increases security as data can be kept separate from other areas of the network

7. The internet

   • DNS
     • Domain Name Server
   • Hosting
     • The cloud uses the internet to store files and applications Services that use the cloud are those such as Dropbox, Google Drive/Docs
   • The cloud
     • The cloud uses the internet to store files and applications Services that use the cloud are those such as Dropbox, Google Drive/Docs
   • The internet as a WAN
     • Is the biggest WAN
   • MAC addressing
     • A media access control address of a device is a unique identifier assigned to network interfaces for communications at the data link layer of a network segment
   • IP addressing
     • An Internet Protocol address is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication

8. Protocols

   • TCP/IP
     • transmission control protocol
     • Internet Protocol
   • HTTP
     • Hyper Text transfer protocol
   • HTTPS
     • HTTP secure
   • FTP
     • file transfer protocol
   • POP3
     • Post Office protocol
   • IMAP
     • Internet message access protocol
   • SMTP
     • Simple mail transfer protocol
   • What is a protocol?
     • the official procedure or system of rules governing communication

9. What is a network?

   • a group or system of interconnected people or things.

10. The concept of layers

    • A layer is a division of network functionality

11. Packet switching

    • Routers and switches make sure the packets arrive at the correct destination The protocol that is responsible for packet switching is IP.

12. Mesh Network

    • Pros
      • Many Different routes for the data to use
      • No single point of failure
    • Cons
      • Hard to set up/very complex
      • Latency
      • Normally needs IT specialists

Imagens e arquivos do mapa