Which protocol is responsible for reliable transmission of data across a network?

Which protocol is responsible for reliable transmission of data across a network?

• A. IP
• B. UDP
• C. TCP
• D. DNS

Answer: (C)

Reliable data delivery over a network is provided by a transport protocol that guarantees integrity and order. The protocol that does this is TCP, which is connection-oriented and establishes a session before data is sent. Each piece of data gets a sequence number and a checksum, the receiver sends acknowledgments, and the sender retransmits any data that isn’t acknowledged. TCP also manages flow control to prevent overwhelming the recipient and uses congestion control to adapt to network conditions. These mechanisms work together to ensure data arrives correctly, in order, and without missing parts. In contrast, IP handles routing and addressing but doesn’t guarantee delivery, order, or error checking at the endpoints. UDP offers a faster, simpler, connectionless approach but provides no reliability guarantees—packets can arrive out of order, be duplicated, or be lost. DNS is for translating domain names to IP addresses and isn’t about transporting data reliably. So the protocol that provides reliable transmission is TCP.

Reliable data delivery over a network is provided by a transport protocol that guarantees integrity and order. The protocol that does this is TCP, which is connection-oriented and establishes a session before data is sent. Each piece of data gets a sequence number and a checksum, the receiver sends acknowledgments, and the sender retransmits any data that isn’t acknowledged. TCP also manages flow control to prevent overwhelming the recipient and uses congestion control to adapt to network conditions. These mechanisms work together to ensure data arrives correctly, in order, and without missing parts.

In contrast, IP handles routing and addressing but doesn’t guarantee delivery, order, or error checking at the endpoints. UDP offers a faster, simpler, connectionless approach but provides no reliability guarantees—packets can arrive out of order, be duplicated, or be lost. DNS is for translating domain names to IP addresses and isn’t about transporting data reliably.

So the protocol that provides reliable transmission is TCP.