1. Define Network
A network is a collection of interconnected devices (computers, servers, switches, routers) that communicate and share resources using a communication medium.
Example: Internet, LAN.
2. Difference between IMAP and POP
| Feature | IMAP (Internet Message Access Protocol) | POP (Post Office Protocol) |
|---|---|---|
| Storage | Keeps emails on the server | Downloads & usually deletes from server |
| Sync | Syncs across devices | No automatic sync |
| Use | Access from multiple devices | Access from one device |
3. Network Topology & Types
Definition: Network topology is the physical or logical arrangement of nodes and links in a network.
Types:
- Bus
- Star
- Ring
- Mesh
- Tree
- Hybrid
📷 Example Diagram:
Star Topology:
[Switch]
/ | \
PC1 PC2 PC3
4. Metrics influencing performance of computer networks
- Bandwidth (data rate)
- Throughput (actual data transfer rate)
- Latency (delay)
- Jitter (variation in delay)
- Packet loss rate
- Error rate
5. Uses of HTTP
- Transfer of web pages (HTML, CSS, JS)
- Retrieval of multimedia content
- API communication between applications
- Supports client–server communication over the web.
6. What is URL?
URL (Uniform Resource Locator) specifies the address of a resource on the internet.
Example: https://www.example.com/index.html
Format: protocol://hostname/path
7. Use of MIME Extension
MIME (Multipurpose Internet Mail Extensions) allows email to support:
- Text in different character sets
- Non-text attachments (images, audio, video, PDF)
- Multiple parts in a single message.
8. Transmission Media with Examples
Definition: The physical path between sender and receiver.
Examples:
- Guided: Twisted pair cable, Coaxial cable, Optical fiber
- Unguided: Radio waves, Microwaves, Infrared
9. Define Socket
A socket is an endpoint for sending or receiving data between two devices over a network.
Format: (IP address, Port number)
10. Define Encapsulation & De-capsulation
- Encapsulation: Wrapping data with protocol headers (and trailers) as it moves down OSI layers.
- De-capsulation: Removing headers/trailers as data moves up layers at the receiver.
11. Features provided by layering
- Modularity
- Interoperability
- Simplified troubleshooting
- Flexibility for protocol changes
- Standardization
12. Metrics to measure network performance
(Same as Q4, but as a direct list for answer key)
- Bandwidth
- Throughput
- Latency
- Jitter
- Packet loss rate
- Error rate
13. Two types of connections in FTP
- Control connection – for sending commands/responses
- Data connection – for transferring files
14. Role of DNS Resolver
The DNS resolver queries DNS servers to find the IP address of a domain name, caching results for faster access.
Example: Resolving www.example.com → 93.184.216.34
15. Functions of POP3
- Authenticate user
- Retrieve emails from mail server
- Delete messages from server (optional)
- Download messages to client
16. How MIME enhances SMTP
- Adds support for multimedia content (images, audio, video)
- Allows different character sets
- Enables sending multiple attachments
Services by User Agent:
- Compose, send, receive, and display messages
- Manage mailbox
- Provide address book
17. Define SNMP
SNMP (Simple Network Management Protocol) is used to monitor and manage devices (routers, switches, servers) on a network.
18. Advantages of TCP over UDP
- Reliable (acknowledgements, retransmissions)
- Connection-oriented
- Ordered delivery of packets
- Flow and congestion control
19. Define Socket Address
A socket address uniquely identifies a process on a host, consisting of IP address + Port number.
Example: 192.168.1.10:80