TCP/IP:The TCP/IP protocol is a stack of protocols. consisting of several different protocols, on layes 3 and 4 of the OSI model, including TCP, IP, ARP, DHCP, ICMP, and others.
TCP – Transport Control Protocol: is a layer 4 protocol that is commonly used because it provides an efficient method of reliable bi-directional communication, where computers can transmit and receive data simultaneously.
IP - Internet Protocol: is a layer 3 protocol that provide the addressing system that allows communication on the network, IP is a connectionless protocol which means that it needs of TCP to ensure the reliability of transmitted data.
The TCP 3 way handshake:before you can transfer data from another computer, the sender and the receiver need to complete the TCP 3 way handshake. The handshake is a 3 step process where the client computer establishes a connection with the server computer. All of this is possible through the different types of TCP packets and flags: SYN, SYN/ACK, ACK.
You can see the full 3 way handshake in the following figure. Read the rest of this entry »