1. Application Layer
   1. HTTP
   2. SMTP
   3. LPD
   4. FTP
   5. TFTP
   6. SNMP
   7. TELNET
   8. API
2. Presentation Layer
   1. TIFF
   2. JPEG
   3. GIF
   4. MPEG
   5. MIDI
   6. ASCII
   7. EBCDIC
   8. compression
   9. encryption
3. Session Layer
   1. Application-to-Application
   2. RPC
   3. NFS
   4. SQL
   5. NetBIOS
   6. Simplex
   7. Half-duplex
   8. Full-duplex
4. Transport Layer
   1. computer-to-computer
   2. TCP
   3. UDP
   4. SPX
   5. SSL/TLS
5. Network Layer
   1. IP
   2. IPX
   3. ICMP
   4. RIP
   5. OSPF
   6. BGP
   7. IGMP
6. Data Link Layer
   1. Logical Link Control (LLC)-IEEE802.2
   2. Media Access Control (MAC)-IEEE802.3
   3. SLIP
   4. PPP
   5. ARP
   6. RARP
   7. L2F
   8. L2TP
   9. FDDI
   10. ISDN
7. Physical Layer
   1. High-Speed Serial Interface (HSSI)
   2. X.21
   3. EIA/TIA-232 and EIA/TIA-449