Network: Terms Flashcards
What is LAN?
- Local Area Network
- A network found on a single site E.g. A school
What is WAN?
- Wide Area Network
- A network found across a large geographical area.
What is Wireless Transmission?
Uses radio waves to transmit data. E.g. WiFi, Bluetooth, RFID
What is Wired Transmission?
Uses cables to connect and send data. E.g. Ethernet/Coaxiel copper cables or Fibre Optic
What is a Switch?
Connects devices on a network and ensures packets are forwarded to the correct address
What is a Hub?
Connects devices on a network
What is Packet Witching?
- File is broken into packets
- Packets directed to destination via routers
- Packets take different paths and may arrive in different order.
- Receiving computer assembles packets in order using packet headers.
Explain the structure of Data Packets
Header: IP address of source and destination. Sequence number, total number of packets and Checksum
Payload/Body: Data from file
Footer: End of packet flag
What is a Router?
- Connects networks together.
- Directs packets on the Internet as part of packet switching.
- They use routing tables to select the most efficient route
What is a URL?
- Uniform Resource Locator (Web address)
- An Internet browser would send a request to a DNS server to get the IP address of a website
What is Encryption?
Disguising a message/data so it can not be understood by scrambling data. E.g. Caesar Cypher
What is a Protocol?
Rules that govern communication. E.g. IP, FTP, etc
What is an IP address?
An address of a device or network
What is a MAC address?
A unique serial number given to networking hardware E.g. 00-B0-D0-63-C2-26
What are the main Protocols?
TCP/IP
HTTP/HTTPS
FTP
SMTP
POP/IMAP
What is TCP/IP
- The protocol that enables communication over the internet
What is HTTP/HTTPS?
- Hyper Text Transfer Protocol (secure). Allows web server and client to communicate
What is FTP?
- File Transfer Protocol
- The protocol that allows files to be transferred to a server
What is SMTP?
- Simple Mail Transfer Protocol.
- How emails are sent over a network to a mail server
What is POP / IMAP
- Post Office Protocol / Internet Message Access Protocol
- Protocols about how emails are downloaded from mail servers
- POP deletes off server IMAP doesn’t
- POP is obsolete to IMAP
What is a Packet?
- Data sent over a network is broken into packets
- Each packet has an IP address, packet number and payload (data)
What is a Checksum?
A number that packets often have as a method of validation
Explain the 4 Layer TCP/IP Model:
Application Layer - Decoding the data. E.g. turning data into websites. HTTP/IMAP/FTP
Transport Layer - Splitting data into packets. TCP
Internet Layer - Making connection and directing packets. Adding IP addresses to packets. IP
Link Layer - Passing data over a physical network. Ethernet or WiFi
What is Latency?
How long it takes a packet to arrive at the destination. The delay between sending and receiving
