TCP Reliability Mechanism

Understanding TCP's approach to ensuring reliable data delivery

This question tests your grasp of the fundamental mechanisms that make TCP a reliable transport protocol, as opposed to the connectionless, best-effort delivery of UDP. It is a conceptual question that interviewers use to confirm you understand the architectural choices behind TCP/IP.

A strong answer identifies and explains the specific techniques TCP employs to guarantee ordered, error-checked delivery—techniques that form the backbone of how the internet handles critical data. The question rewards clear reasoning about why these mechanisms exist and how they interact to provide end-to-end reliability.

• Sequence numbers and acknowledgment schemes
• Checksums and error detection
• Retransmission and timeout handling
• In-order delivery and buffering