TCP

Question 1

What is TCP?

Answer 1

TCP (Transmission Control Protocol) is a reliable, connection-oriented transport-layer protocol that ensures error-free, ordered, and complete data delivery between applications over potentially unreliable networks.

Question 2

What are the key features of TCP?

Answer 2

Connection-Oriented: Requires a handshake to establish a logical connection.
Stream-Oriented: Hides packetization from applications, providing continuous data.
Reliability: Achieved through acknowledgments (ACKs), retransmissions, and checksums.
Full Duplex: Supports bidirectional data transfer

Question 3

What is the TCP Three-Way Handshake?

Answer 3

SYN: Client requests a connection.
SYN-ACK: Server acknowledges and requests connection.
ACK: Client confirms connection.
This process ensures both parties are ready to communicate.

Question 4

How does TCP ensure reliability?

Answer 4

Acknowledgments (ACKs): Confirmation that data has been received.
Retransmissions: Unacknowledged packets are resent after a timeout.
Sliding Window Protocol: Allows multiple packets to be sent before an ACK is required, improving throughput.

Question 5

What is the difference between segmentation and fragmentation in TCP?

Answer 5

Segmentation: Divides data streams into smaller packets at the TCP layer.
Fragmentation: Divides packets into smaller pieces at the IP layer if they exceed the network’s Maximum Transmission Unit (MTU).

Question 6

How does error control work in TCP?

Answer 6

TCP uses a checksum to verify data integrity. If the checksum doesn’t match, the data is retransmitted.

Question 7

What is piggybacking in TCP?

Answer 7

Piggybacking involves including ACKs in outgoing data packets to reduce overhead and increase efficiency.

Question 8

What are TCP ports used for?

Answer 8

TCP ports uniquely identify connections between applications. For example:

Port 80: HTTP
Port 25: SMTP
Port 443: HTTPS

Question 9

What is the role of sockets in TCP?

Answer 9

Sockets represent endpoints for network communication. TCP sockets establish either active (client-side) or passive (server-side) connections.

Question 10

How does TCP handle retransmission and timeouts?

Answer 10

Retransmissions: Triggered after increasing timeouts to handle congestion.
Unacknowledged data is resent until either successfully delivered or deemed undeliverable.

Question 11

What information is included in a TCP header?

Answer 11

The TCP header contains:

Source and Destination Ports
Sequence and Acknowledgment Numbers
Window Size
Checksum for error detection.

Question 12

What is the summary of TCP characteristics?

Answer 12

TCP provides a robust transport-layer protocol suitable for reliable communication, ensuring order, integrity, and delivery through acknowledgments, segmentation, and error control mechanisms.

Question 13

How does TCP differ from UDP?

Answer 13

TCP: Reliable, connection-oriented communication, with guaranteed data integrity and ordering.
UDP: Connectionless, with low overhead and fast delivery, but without reliability guarantees.