TCP (Transmission Control Protocol) is a standard communications protocol used for sending data over networks, including the internet. It is one of the core protocols of the Internet Protocol Suite (TCP/IP).
TCP is a connection-oriented protocol, which means that it establishes a virtual connection between two endpoints before any data can be exchanged. This connection provides a reliable, ordered, and error-checked delivery of data, with acknowledgments for all data received.
TCP divides data into small packets and transmits them from the sender to the receiver. The packets are then reassembled in the correct order at the destination. TCP uses a sliding window mechanism to ensure that packets are delivered in sequence and retransmits lost packets.
TCP is used by a wide range of applications, including web browsers, email clients, and file transfer protocols. It provides a reliable transport layer for these applications, ensuring that data is delivered accurately and efficiently. However, the reliability of TCP comes at the cost of increased overhead and slower transmission speeds compared to UDP (User Datagram Protocol), another popular transport protocol.
The Transmission Control Protocol (TCP) is a core protocol in the Internet Protocol (IP) suite, which is responsible for providing reliable, ordered, and error-checked delivery of data between applications running on different hosts on a network.
Here's how TCP works:
Establishing a connection: Before data can be transmitted, a connection must be established between the two hosts. This is done through a three-way handshake, where the sender sends a SYN packet to the receiver, the receiver responds with a SYN-ACK packet, and the sender sends an ACK packet in response.
Sending data: Once the connection is established, the sender can begin sending data to the receiver. The data is broken up into segments of a maximum size determined by the Maximum Segment Size (MSS) negotiated during the connection setup. Each segment is numbered and includes a sequence number and an acknowledgment number.
Ensuring reliability: TCP uses a system of acknowledgments and retransmissions to ensure reliable delivery of data. The receiver sends an acknowledgment (ACK) packet to the sender for each received segment, and the sender will retransmit any segments that are not acknowledged within a certain timeout period.
Flow control: TCP also includes flow control mechanisms to prevent the sender from overwhelming the receiver. The receiver advertises a window size, indicating how much data it can receive at a time, and the sender adjusts its transmission rate accordingly.
Closing the connection: Once all the data has been transmitted, the connection is closed. This is done through a four-way handshake, where the sender sends a FIN packet, the receiver responds with an ACK packet, the receiver sends a FIN packet, and the sender responds with an ACK packet.
Overall, TCP provides a reliable and ordered data transfer service, making it widely used in applications that require a high degree of data integrity, such as file transfer, email, and web browsing.