OSI Reference Model
| # | Layer | Description | Equip./Protocol/App |
| 1. | Physical | The transmition of data over physical medium. | CAT5 Cable, Hub, Switch |
| 2. | Data Link | Packages bits into frames, adds CRC | Network Card |
| 3. | Network | Addressing, IP to MAC conversion & Routing | IP, IPX, NW Link, NetBEUI |
| 4. | Transport | Formats data and provides error handling | NetBeui, TCP, SPX & NW Link |
| 5. | Session | Synchronizes computers and allows them to communicate | NetBios |
| 6. | Presentation | Protocol conversion & encryption | NCP, AFP, TDI |
| 7. | Application | Provides network access for applications | NCP, SMB, SMTP, FTP, SNMP, Telnet, Appletalk |