Networks[]
Local Area Network (LAN) Metropolitan Area Network (WAN) Wide Area Network (WAN)
Levels[]
application
- FTP, SMTP, HTTP
transport
- TCP, UDP
network
- IP, routing protocols
link
- PPP, Ethernet
physical
Protocols[]
- How to exchange information
- Example: HTTP, FTP, IRC, etc.
Services
- What networks offer
Interfaces
- How services can be accessed
Developed by the RFC system and the holy IETF (Internet Engineering Task Force)
TCP[]
reliable, in order byte stream data transfer
- loss: acknowledgements and retransmissions
flow control
- sender doesn't overwhelmn sender
- relatively slow
UDP[]
User datagram protocol [RFC 768]
- connectionless
- unreliable data transfer
- no flow control
- no congestion control
- fast
Circuit Switching[]
FDM: Frequency division multiplexing TDM: Time division multiplexing