Which data unit is used by the Transport Layer when messages are broken up for transmission?

Which data unit is used by the Transport Layer when messages are broken up for transmission?

• A. Segment
• B. Datagram
• C. Frame
• D. Packet

Answer: (A)

Segments are the data unit used by the Transport Layer when messages are broken up for transmission. The Transport Layer (as in TCP) takes a stream of bytes from the application and divides it into manageable pieces called segments. Each segment carries a TCP header with information like source and destination port numbers, sequence numbers, and control bits, which enables reliable delivery, proper ordering, error checking, and flow control. This segmentation is what allows a single application’s data to be sent over a network in chunks while still ensuring it can be reassembled correctly at the destination. Datagrams belong to the Transport Layer in UDP, not TCP, and are used for connectionless transmission. Frames are units at the Data Link layer, and packets are the Network layer (IP) units. So the data unit for breaking messages in the Transport Layer is a segment.

Segments are the data unit used by the Transport Layer when messages are broken up for transmission.

The Transport Layer (as in TCP) takes a stream of bytes from the application and divides it into manageable pieces called segments. Each segment carries a TCP header with information like source and destination port numbers, sequence numbers, and control bits, which enables reliable delivery, proper ordering, error checking, and flow control. This segmentation is what allows a single application’s data to be sent over a network in chunks while still ensuring it can be reassembled correctly at the destination.

Datagrams belong to the Transport Layer in UDP, not TCP, and are used for connectionless transmission. Frames are units at the Data Link layer, and packets are the Network layer (IP) units. So the data unit for breaking messages in the Transport Layer is a segment.