What does the TCP layer use to establish reliable communication?

What does the TCP layer use to establish reliable communication?

• A. UDP
• B. Connectionless transport
• C. Sequence numbers
• D. IP addresses

Answer: (C)

The TCP layer utilizes sequence numbers to establish reliable communication between devices. In the Transmission Control Protocol (TCP), sequence numbers are crucial because they allow the sender and receiver to keep track of the segments of data being transmitted. Each byte of data sent is assigned a unique sequence number that helps in reordering the segments at the receiving end if they arrive out of order. This mechanism not only ensures that data can be accurately reassembled but also enables the detection of any lost segments during transmission. If the sender does not receive an acknowledgment for a segment sent within a specified timeframe, it can retransmit that particular segment using its sequence number. This capability for acknowledgments and reordering, all managed through the use of sequence numbers, is fundamental to achieving the reliable, connection-oriented service that TCP is known for. The other options do not directly relate to how TCP ensures reliability. For instance, UDP is a connectionless protocol that does not include mechanisms for reliability, such as acknowledgments or sequence control. Connectionless transport, as a concept, refers to protocols that operate without establishing a dedicated end-to-end connection, which is contrary to the operation of TCP. IP addresses play a critical role in routing packets to the correct destination but do not handle the reliability aspect of

The TCP layer utilizes sequence numbers to establish reliable communication between devices. In the Transmission Control Protocol (TCP), sequence numbers are crucial because they allow the sender and receiver to keep track of the segments of data being transmitted. Each byte of data sent is assigned a unique sequence number that helps in reordering the segments at the receiving end if they arrive out of order.

This mechanism not only ensures that data can be accurately reassembled but also enables the detection of any lost segments during transmission. If the sender does not receive an acknowledgment for a segment sent within a specified timeframe, it can retransmit that particular segment using its sequence number. This capability for acknowledgments and reordering, all managed through the use of sequence numbers, is fundamental to achieving the reliable, connection-oriented service that TCP is known for.

The other options do not directly relate to how TCP ensures reliability. For instance, UDP is a connectionless protocol that does not include mechanisms for reliability, such as acknowledgments or sequence control. Connectionless transport, as a concept, refers to protocols that operate without establishing a dedicated end-to-end connection, which is contrary to the operation of TCP. IP addresses play a critical role in routing packets to the correct destination but do not handle the reliability aspect of