Solved S.Y. B.B.A. (Computer Application) CA-401: NETWORKING (2019 Pattern) Exam Paper
Here are the detailed explanations and answers to the questions from the S.Y. B.B.A. (C.A.) CA-401 Networking exam paper:
01) Attempt any three of the following:
a) Define Network Topology? Explain different types of topologies.
- Network Topology refers to the arrangement or structure of various elements (links, nodes, etc.) in a computer network. It describes how different network devices (such as computers, routers, switches) are connected and how data flows between them.
Types of Network Topologies:
- Bus Topology:
- All devices are connected to a central cable (bus).
- Data is sent in both directions, and devices listen to data on the bus.
- Easy to install, but if the bus fails, the whole network goes down.
- Star Topology:
- All devices are connected to a central device (hub or switch).
- If one device fails, it does not affect others, but if the hub fails, the whole network fails.
- Ring Topology:
- Devices are connected in a circular fashion.
- Data travels in one direction from one device to the next.
- If one device or connection fails, the entire network may be affected.
- Mesh Topology:
- Each device is connected to every other device in the network.
- Provides redundancy and fault tolerance, as there are multiple paths for data transmission.
- Hybrid Topology:
- A combination of two or more topologies.
- Flexible and scalable, but more complex and expensive.
b) Explain function of each layer of ISO-OSI reference Model.
The ISO-OSI (Open Systems Interconnection) model is a conceptual framework used to understand network communication. It divides the communication process into seven layers:
- Physical Layer:
- Deals with the transmission of raw data over physical media (cables, switches).
- Defines electrical and physical specifications like voltage, cables, and connectors.
- Data Link Layer:
- Responsible for node-to-node data transfer and error detection.
- Divided into two sublayers: MAC (Media Access Control) and LLC (Logical Link Control).
- Network Layer:
- Handles routing and forwarding of data packets between devices.
- Defines logical addressing, such as IP addresses.
- Transport Layer:
- Ensures reliable data transfer between devices.
- Provides error correction, flow control, and segmentation of data into packets (TCP, UDP).
- Session Layer:
- Manages sessions or connections between applications.
- Ensures communication is properly established, maintained, and terminated.
- Presentation Layer:
- Translates data formats between the application and transport layers.
- Ensures data is in a readable format (e.g., encryption, compression).
- Application Layer:
- The topmost layer, where end-user applications (such as email or web browsers) operate.
- Provides services like HTTP, FTP, SMTP.
c) What’s wireless transmission? Explain any two media in detail.
Wireless Transmission refers to the transfer of data without using physical cables. It uses electromagnetic waves to transmit information across the air.
Types of Wireless Transmission Media:
- Radio Waves:
- Commonly used for long-distance communication, such as AM/FM radio broadcasting and wireless internet.
- Radio waves can travel through walls and are highly flexible but may suffer interference from physical obstructions or other signals.
- Microwaves:
- Higher frequency than radio waves, commonly used for point-to-point communication (e.g., satellite communication, radar).
- Requires line-of-sight between transmitter and receiver due to limited ability to bend around obstacles.
d) Define the bridge? Explain the types of bridge.
A bridge is a networking device used to connect two or more network segments to form a single network. It operates at the Data Link Layer (Layer 2) of the OSI model.
Types of Bridges:
- Transparent Bridge:
- It automatically learns the MAC addresses of devices on the network and forwards frames based on this information.
- It is used in Ethernet networks to divide collision domains.
- Source Routing Bridge:
- It is used in Token Ring networks and allows the sender to specify the route to be used by data packets.
- Remote Bridge:
- It connects two geographically separated networks over long distances, usually through leased lines.
02) Attempt any three of the following:
a) Define Computer Network? Explain goals of Computer Network.
A Computer Network is a collection of interconnected devices (computers, printers, servers, etc.) that share resources and data using communication protocols.
Goals of a Computer Network:
- Resource Sharing:
- Enables multiple users to share resources like printers, files, and internet connections.
- Reliability and Fault Tolerance:
- Ensures communication continues even if one part of the network fails (redundant paths, backup devices).
- Scalability:
- Ability to easily add new devices or resources as the network grows.
- Security:
- Protects data and resources from unauthorized access or cyber threats.
b) Explain different types of Addresses.
- IP Address:
- A unique identifier for a device on a network, used to locate the device across the internet or an intranet.
- Types: IPv4 (32-bit), IPv6 (128-bit).
- MAC Address:
- A hardware address assigned to network interfaces at the Data Link Layer (Layer 2).
- It is globally unique and used for device identification on a local network.
- Port Address:
- A numerical identifier for processes or services on a device, used in the Transport Layer (TCP/UDP).
- Logical Address:
- Refers to addresses used in the Network Layer (IP address) to route data across networks.
c) Explain propagation methods in detail.
Propagation refers to how signals travel from one point to another. The main methods of propagation are:
- Line-of-Sight Propagation:
- The signal travels directly from the transmitter to the receiver without any obstructions.
- Typically used in satellite communication or microwave communication.
- Ground Wave Propagation:
- Signals travel along the ground, bending over the Earth’s curvature.
- Used for AM radio transmissions.
- Sky Wave Propagation:
- Signals are reflected by the ionosphere and bounce back to Earth.
- Used in shortwave radio transmission.
- Space Wave Propagation:
- Signals travel directly through the air and can include satellite communication or microwave line-of-sight communication.
d) Explain Firewall and its Security Features.
A Firewall is a security system designed to monitor and control incoming and outgoing network traffic. It acts as a barrier between a trusted internal network and untrusted external networks (such as the internet).
Security Features of a Firewall:
- Packet Filtering:
- Inspects packets based on predefined rules and allows or blocks traffic based on source, destination IP address, and port number.
- Stateful Inspection:
- Tracks the state of active connections and makes decisions based on the context of the traffic.
- Proxying and Network Address Translation (NAT):
- Firewalls can hide the internal network by modifying packet headers and masking internal IP addresses.
- Intrusion Detection and Prevention:
- Identifies and blocks potential threats, such as malicious traffic or attempts to exploit vulnerabilities.
03) Attempt any three of the following:
a) Draw TCP/IP model and state the function of each layer.
Here’s a brief overview of the TCP/IP model:
- Application Layer:
- Provides network services directly to end-users (e.g., HTTP, FTP).
- Transport Layer:
- Responsible for reliable communication (e.g., TCP, UDP).
- Internet Layer:
- Handles packet routing (e.g., IP).
- Network Interface Layer:
- Deals with physical transmission of data on the network (e.g., Ethernet).
b) Compare connection-oriented and connectionless services.
Connection-Oriented Services:
- TCP is a good example (e.g., telephone network).
- Establishes a reliable, continuous connection between sender and receiver before transmitting data.
- Guarantees delivery, order, and error recovery.
Connectionless Services:
- UDP is a good example (e.g., IP).
- No need to establish a connection before transmission.
- Faster but less reliable, as there is no guarantee of delivery.
c) What is Router? Explain its components.
A Router is a device that forwards data packets between different networks. It operates at the Network Layer (Layer 3) of the OSI model.
Components of a Router:
- Routing Table:
- Stores information about different network destinations and the best paths to them.
- Ports:
- Physical or virtual interfaces for connecting to different networks.
- CPU:
- Handles processing and decision-making tasks, such as forwarding packets.
- Memory:
- Stores the operating system, routing table, and packet buffers.
d) What is Ethernet? What are its types? Explain any one in detail.
Ethernet is a widely used LAN (Local Area Network) technology that uses a protocol to allow devices to communicate on a network.
Types of Ethernet:
- 10BASE-T (10 Mbps): Traditional Ethernet with a maximum speed of 10 Mbps over twisted pair cables.
- 100BASE-TX (Fast Ethernet): Offers speeds of 100 Mbps.
- 1000BASE-T (Gigabit Ethernet): Offers speeds of 1 Gbps.
- 10GBASE-T (10 Gigabit Ethernet): Offers speeds of 10 Gbps.
04) Attempt any three of the following:
a) Explain IEEE standards 802.11 in detail.
IEEE 802.11 refers to a set of standards for wireless local area networks (WLANs). These standards specify how devices communicate over wireless networks (Wi-Fi).
- 802.11a: Provides speeds up to 54 Mbps using the 5 GHz frequency band.
- 802.11b: Provides speeds up to 11 Mbps using the 2.4 GHz frequency band.
- 802.11g: Provides speeds up to 54 Mbps using the 2.4 GHz frequency band.
- 802.11n: Supports up to 600 Mbps, using both 2.4 GHz and 5 GHz frequencies.
b) Compare ISO-OSI reference model and TCP/IP model.
| Aspect | OSI Model | TCP/IP Model |
|---|---|---|
| Layers | 7 layers (Physical, Data Link, Network, Transport, Session, Presentation, Application) | 4 layers (Link, Internet, Transport, Application) |
| Standardization | Developed by ISO | Developed by ARPANET |
| Focus | Conceptual and logical framework | Practical implementation |
c) What is cryptography? Explain encryption and decryption process.
Cryptography is the practice of securing communication and data through encoding messages so that only authorized parties can read them.
Encryption: The process of converting plaintext (original data) into ciphertext using a key.
Decryption: The process of converting ciphertext back to plaintext using a key.
d) Explain Fiber optic cable in detail.
Fiber optic cables use light to transmit data over long distances. They consist of glass or plastic fibers that carry light signals.
- Core: The central part of the fiber that carries the light signal.
- Cladding: The outer layer that reflects the light back into the core.
- Jacket: The protective outer covering.
Fiber optics offer high bandwidth, low attenuation, and immunity to electromagnetic interference.
05) Write notes on (Any Two):
a) Modes of Communication.
- Unidirectional: Data flows in one direction (e.g., radio broadcasting).
- Bidirectional: Data flows in both directions, can be synchronous or asynchronous (e.g., telephone).
b) Bluetooth Architecture.
- Bluetooth uses a master-slave architecture, where one device acts as a master and controls up to seven slave devices.
c) MAC Sublayer with its Frame Format.
- The MAC sublayer handles channel access mechanisms, determining how devices access the shared communication medium. It is responsible for framing, addressing, and error control.
d) Copyright.
- Copyright is a legal protection granted to the creators of original works, preventing unauthorized use of their creations.