Networks

Networks

1. LAN: local area network

2. WAN: wide area network

3. Topologies

   • bus: lots of collisions, high chance of catastrophic failure
   • star: Low chance of collisions, low chance of catastrophic failure. Expensive
   • mesh
     • circuit switching: single route which locks others out but comes without delay
     • packet switching: separate packets but comes with delay - allows use of other paths
     • pathfinding:
   • ring: reduced collisions, high chance of catastrophic failure

4. Protocols

   • standard protocols: well known protocols that are used by a wide range and variety of applications
     • HTTP: (HyperText Transfer Protocol) used for requesting a HTML file from a webserver
     • HTTPS: a secure version which encrypts data before sending it to avoid it being intercepted
     • FTP: (File Transfer Protocol) used for transferring files between two computers
     • POP3: ( Post Office Protocol 3) is a protocol for downloading email from a mail server
     • SMTP: (Simple Mail Transfer Protocol) used to send to mail server
     • IMAP: ( Internet Message Access Protocol) replaced POP3 when web-based email took off

5. IP address

   • DNS: a DNS server is a large address book