Which types of packets does TCP retransmit?

TCP (Transmission Control Protocol) is designed to ensure reliable data transmission over networks. One of its key features is the mechanism for retransmitting packets that have either been lost in transit or corrupted during transmission.

Packet loss can occur for several reasons, such as network congestion or faulty hardware, leading to a situation where the sender sends data but doesn't receive the expected acknowledgment (ACK) from the receiver within a timeout period. In such cases, TCP interprets this lack of acknowledgment as a signal that the packet may have been lost, prompting retransmission.

Corrupted packets are identified through the inclusion of checksums in the TCP segment header. When a packet arrives at its destination, the receiving system calculates the checksum and compares it to the one included in the packet. If the checksums do not match, this indicates that the packet has been corrupted during transit. TCP will then ignore this corrupted packet and retransmit it after a timeout period.

By employing these mechanisms for lost and corrupted packets, TCP ensures a more reliable communication channel, providing orderly and accurate delivery of data. Thus, the answer regarding the types of packets that TCP retransmits is correct, as it specifically focuses on the handling of lost and corrupted packets, which are key elements of TCP's reliability features