transportréteg

Transport layer is a conceptual layer within the layered architecture of network protocols, most famously represented by the Internet protocol suite (TCP/IP) and the OSI model. Its primary function is to provide logical communication between applications running on different hosts. While the network layer (like IP) handles the routing of data packets across networks, the transport layer ensures that data is delivered reliably and in the correct order from the originating application process to the destination application process.

Key responsibilities of the transport layer include segmenting data from the application layer into smaller units called segments, adding header information to these segments, and reassembling them at the destination. It also manages flow control to prevent a fast sender from overwhelming a slow receiver and congestion control to avoid network collapse. Error detection and correction mechanisms are often implemented to ensure data integrity.

The most common transport layer protocols are Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). TCP is a connection-oriented protocol that provides reliable, ordered, and error-checked delivery of a stream of bytes. It is suitable for applications where data integrity and order are critical, such as web browsing, email, and file transfer. UDP, on the other hand, is a connectionless protocol that offers best-effort delivery with no guarantees of reliability, order, or error checking. It is faster and has lower overhead, making it suitable for applications like online gaming, video streaming, and DNS where speed is prioritized over perfect reliability.