What is TCP/IP?

What is TCP/IP?

TCP/IP, Transmission Control Protocol/Internet Protocol, is a suite of communications protocols used to interconnect network devices on the Internet. TCP/IP implements layers of protocol stacks, and each layer provides a well-defined network services to the upper layer protocol. TCP and IP are the two protocols used by TCP/IP, as well as the (higher) application, (lower) data link and (lower) physical layer protocols.

Layer Protocols
5. Application DNS, FTP, HTTP, IMAP, POP3, SMTP, SSH, Telnet, SSL, ...
4. Transport TCP, UDP, ...
3. Network IP (IPv4, IPv6), ICMP, ARP, ...
2. Data Link 802.3 (Ethernet), 802.11 (Wi-Fi), PPP, ...
1. Physical Ethernet (NIC), Wireless (NIC), Cat 5/RJ-45, ...


Ethernet Overview

1. What is Ethernet?

Ethernet is the most widely used local area network (LAN) technology, that defines wiring and signaling standards for the physical layer of TCP/IP. Ethernet was originally standardized as IEEE 802.3 with a data transmission rate of 10 Mb/s. Newer versions of Ethernet were introduced lately to offer higher data rates. Fast Ethernet and Gigabit Ethernet support data rates of 100 Mbps and 1 Gbps (1000 Mbps) respectively. An Ethernet LAN may use coaxial cable (10Base2), unshielded twisted pair wiring (10BaseT, 100BaseT and 1000BaseT), or fiber optic cable. Ethernet devices compete for access to the network using a protocol called Carrier Sense Multiple Access with Collision Detection (CSMA/CD). With prosperity of Internet, Wi-Fi, the wireless LAN technology standardized by IEEE 802.11, is used in hybrid with Ethernet LAN to offer portability.


2. Ethernet Standards

IEEE 802.3 is the signaling standards for Ethernet, and IEEE 802.11 is the standards for Wi-Fi. The standards documents may be obtained free of charge at the following website: http://standards.ieee.org/getieee802/