TCP/IP - ISO Reference Model
Application	SMTP Telnet FTP/TFTP DNS
Transport	TCP		UDP
Network	IP				ARP RARP ICMP*
Data Link	Ethernet FDDI/CDDI Token Ring
Physical	UTP/STP Fiber Coaxial Cable Wireless

*ICMP messages are encapsulated in an IP datagram, which is
further encapsulated in a data link frame for transmission.

Definitions

• ISO - International Standards Organization
• SMTP - Simple Mail Transfer Protocol
• FTP - File Transfer Protocol
• TFTP - Trivial File Transfer Protocol
• DNS - Domain Name System
• TCP - Transmission Control Protocol
• UDP - User Datagram Protocol
• IP - Internet Protocol
• ICMP - Internet Control Message Protocol
• ARP - Address Resolution Protocol
• RARP - Reverse Address Resolution Protocol
• Ethernet - Based on CSMA/CD technology. (Carrier Sense Multiple Access/Collision Detect)
• FDDI - Fiber Distribution Data Interface
• CDDI - Copper Distribution Data Interface
• Token Ring - Token passing network. (802.5)
• UTP - Unshieled Twisted Pair
• STP - Shieled Twisted Pair