Which protocols operate at the transport layer of the OSI model?

Which protocols operate at the transport layer of the OSI model?

• A. HTTP and HTTPS
• B. TCP and UDP
• C. SMTP and FTP
• D. IP and ICMP

Answer: (B)

The transport layer of the OSI model is responsible for providing communication services directly to the application processes running on different hosts. This layer ensures complete data transfer through flow control, error checking, and segmentation of data into smaller packets. The protocols that operate at this layer are TCP (Transmission Control Protocol) and UDP (User Datagram Protocol). TCP is a connection-oriented protocol, which means it establishes a reliable connection between host devices before data can be sent. It also ensures that data packets are delivered in the correct order and without errors. On the other hand, UDP is a connectionless protocol that allows for faster data transmission by sending packets without establishing a connection, but it does not guarantee delivery or order. This makes TCP and UDP the primary protocols for the transport layer, as they provide essential functions for data transfer and communication between applications across the network. Other options listed, such as HTTP, SMTP, or IP, operate at different layers: HTTP and HTTPS are at the application layer, SMTP also functions at the application layer for email transmission, and IP is part of the network layer, which manages packet routing.

The transport layer of the OSI model is responsible for providing communication services directly to the application processes running on different hosts. This layer ensures complete data transfer through flow control, error checking, and segmentation of data into smaller packets.

The protocols that operate at this layer are TCP (Transmission Control Protocol) and UDP (User Datagram Protocol). TCP is a connection-oriented protocol, which means it establishes a reliable connection between host devices before data can be sent. It also ensures that data packets are delivered in the correct order and without errors. On the other hand, UDP is a connectionless protocol that allows for faster data transmission by sending packets without establishing a connection, but it does not guarantee delivery or order.

This makes TCP and UDP the primary protocols for the transport layer, as they provide essential functions for data transfer and communication between applications across the network. Other options listed, such as HTTP, SMTP, or IP, operate at different layers: HTTP and HTTPS are at the application layer, SMTP also functions at the application layer for email transmission, and IP is part of the network layer, which manages packet routing.