Data Communication

Question 1

Components of Data Communication System

Answer 1

Sender: Device transmitting data.

Receiver: Device receiving data.

Transmission Medium: Path for data (e.g., cables, wireless).

Data: Communicated information (text, images, audio, video).

Question 2

Protocol

Answer 2

Rules for accurate and secure data communication.
Examples: TCP/IP, HTTP, FTP, SMTP.

Question 3

Bandwidth

Answer 3

Maximum data transmission rate.
Measured in bits per second (bps).

Question 4

Latency

Answer 4

Delay between data transmission and reception.
Critical for real-time communication.

Question 5

Error Detection and Correction

Answer 5

Ensures data integrity during transmission.
Techniques: Checksums, parity bits, CRC.

Question 6

OSI Reference Model

Answer 6

Conceptual framework for network communication protocols.
7 Layers: Each with specific functions.

Question 7

Why Do We Need OSI Model?

Answer 7

Solves interconnectivity problems.
Allows vendor flexibility for equipment and software.
Developed by ISO in the late 1970s.

Question 8

Physical Layer (Layer 1)

Answer 8

Transmits raw bit streams over a physical medium.
Components: Cables, switches, NICs.
Protocols: Ethernet, USB, Bluetooth.

Question 9

Data Link Layer (Layer 2)

Answer 9

Node-to-node data transfer, error detection, and correction.
Components: Switches, bridges.
Protocols: Ethernet, PPP, MAC.

Question 10

Network Layer (Layer 3)

Answer 10

Device addressing, packet routing between networks.
Components: Routers.
Protocols: IP, ICMP.

Question 11

Transport Layer (Layer 4)

Answer 11

Ensures complete data transfer, error recovery, and flow control.
Components: Gateways.
Protocols: TCP, UDP.

Question 12

Session Layer (Layer 5)

Answer 12

Manages sessions between applications.
Protocols: NetBIOS, RPC.

Question 13

Presentation Layer (Layer 6)

Answer 13

Translates, encrypts, and compresses data.
Protocols: SSL, TLS.

Question 14

Application Layer (Layer 7)

Answer 14

Provides network services to applications.
Protocols: HTTP, FTP, SMTP, DNS.

Question 15

Practical Example of OSI Model

Answer 15

Application: Email prepared by client.
Presentation: Email translated to network format.
Session: Session established between servers.
Transport: Email segmented for transmission.
Network: Packets routed with IP addresses.
Data Link: Packets framed for transmission.
Physical: Frames sent as signals.