TCP/IP

TCP 'rides' on top of Internet Protocol (IP) in the protocol stack. TCP segments are passed inside the payload section of the IP packets. IP handles IP addressing and routing and gets the packets from one place to another

TCP attaches a header to the application layer data; the header contains fields for the sequence numbers and other information necessary for these mechanisms, and fields for addresses called port numbers, which identify the source and destination applications of the data. The application data with its attached TCP header is then encapsulated within an IP packet for delivery

 

TCP/IP 3Way handshake

-SYN, SYN-ACK, ACK

-Process:

Host A sends a TCP SYN packet to Host B, Host B receives A's SYN

Host B sends a SYN-ACK, Host A receives B's SYN-ACK

Host A sends ACK, Host B receives ACK.

TCP socket connection is ESTABLISHED

Socket: A port number for an application, when coupled with the IP address of the host the application resides on, is called a socket. A socket uniquely identifies every application in a network.