Explain the mechanism of reliable data delivery in the TCP protocol.

The TCP protocol ensures reliable data delivery through several mechanisms:

• Sequence Numbers: each byte of data is assigned a unique number, allowing tracking of order and delivery control.

• Acknowledgments (ACK): the receiver sends an acknowledgment indicating the next expected byte.

• Retransmission: if the sender does not receive an acknowledgment within a timeout, it retransmits the data.

• Integrity Check: each segment contains a checksum that the receiver verifies to detect errors.

• Flow Control: using a receive window, the receiver adjusts the sending rate to prevent buffer overflow.

• Congestion Control: algorithms like slow start and congestion avoidance regulate the transmission rate based on network conditions.

These mechanisms together ensure that data is delivered correctly, in order, and without loss.