Computer Networks
CN Part-1
- What is a Computer Network?
- Goals and Applications of Computer Networking
- Computer Network Components
- Types of Computer Networks
- Network Topology
- Difference between Client Server and Peer to Peer Network
- Layered Architecture in Computer Networks
- Protocol Hierarchy in Computer Networks
- Interfaces and Services in Computer Networks
- Connection Oriented and Connectionless Services
- Service Primitives
- OSI Model
- TCP/IP Model
- Difference between OSI Model and TCP/IP Model
- Encapsulation and Decapsulation in Computer Networks
- Queueing Models in Computer Network
CN Part-2
- Physical Layer in Computer Networks
- Transmission Media in Computer Networks
- Analog and Digital Signals
- Data Rate and Bandwidth
- Encoding Techniques
- Multiplexing in Computer Networks
- Transmission Modes in Computer Networks
- Data Link Layer
- Framing in Data Link Layer
- Flow Control in Data Link Layer
- Error Control in Data Link Layer
- Error Detection and Correction in Computer Networks
- Stop and Wait Protocol
- Sliding Window Protocol
- SDLC(Synchronous Data Link Control) Protocol
- High-Level Data Link Control (HDLC) Protocol
- Point-to-Point Protocol (PPP)
CN Part-3
- MAC Sublayer and MAC Addressing
- Channel Allocation Methods
- ALOHA Protocol (Pure and Slotted ALOHA)
- CSMA/CD and CSMA/CA in Computer Networks
- Ethernet (IEEE 802.3)
- Wireless LANs (IEEE 802.11, Wi-Fi, and Bluetooth Basics)
- Network Layer and Design Issues
- IPv4 and IPv6 Protocols
- Addressing: IP Address, Subnetting, and Supernetting
- Routing Algorithms: Static vs Dynamic, Distance Vector, and Link State
- Routing Protocols: RIP, OSPF, and BGP
- Packet Switching and IP Fragmentation
- Network Layer Protocols: ICMP, ARP, RARP, DHCP, and NAT
CN Part-4
- Transport Layer and Functions
- Process-to-Process Delivery, Ports, and Sockets
- TCP Segment and Three-Way Handshake Connection Establishment
- UDP (User Datagram Protocol): Format and Features
- Flow Control and Error Control in Transport Layer
- Congestion Control: Leaky Bucket, Token Bucket, and TCP Congestion Control
CN Part-5
- Application Layer Architecture and Principles
- Domain Name System (DNS)
- Email Protocols: SMTP, POP3, and IMAP
- File and Web Protocols: FTP, HTTP, and HTTPS
- Remote Access Protocols: Telnet and SSH
- World Wide Web (WWW) and Web Architecture
- Network Security Basics: SSL, TLS, and Cryptography Fundamentals
Client-Server vs Peer-to-Peer Network
Computer networks do tarike se design kiye ja sakte hain:
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Client-Server Network
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Peer-to-Peer (P2P) Network
Chaliye dono ko simple language mein samajhte hain.
1. Client-Server Network
Kya hota hai?
Is type ke network mein ek central computer (Server) hota hai jo baaki sab computers (Clients) ko data ya service provide karta hai.
Examples:
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Jab aap Gmail, Facebook, ya college ki website use karte ho
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Aapka mobile (Client) server se data maangta hai
Diagram:
Kaise kaam karta hai?
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Client server ko request bhejta hai
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Server wo request process karke reply karta hai
Features:
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Centralized system → ek server sabko control karta hai
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Security zyada achhi hoti hai
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Maintenance easy hai (sirf server update karo)
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Server crash ho gaya to sab clients ruk jaate hain
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Server powerful hona chahiye
2. Peer-to-Peer (P2P) Network
Kya hota hai?
Is network mein har computer ek jaisa hota hai — koi server ya client nahi. Sab computers ek dusre ke saath directly data share karte hain.
Examples:
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Bluetooth file sharing
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LAN gaming
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Torrent download karna (BitTorrent)
Diagram:
Kaise kaam karta hai?
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Har computer doosre computer se direct connect hota hai
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Koi central server nahi hota
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Sab computers data share bhi karte hain aur receive bhi
Features:
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Sasta setup (no server required)
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Small network ke liye best
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Security kam hoti hai
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Zyada users hone par slow ho jaata hai
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Maintenance thoda tough (har system alag update karna padta hai)
Client-Server vs Peer-to-Peer: Side-by-Side Comparison
| Feature | Client-Server | Peer-to-Peer (P2P) |
|---|---|---|
| Structure | Server + Multiple Clients | Sab computers equal (Peers) |
| Control | Server control karta hai | Sab control apna-apna karte hain |
| Security | Zyada secure | Kam secure |
| Cost | Mehenga (Server chahiye) | Sasta (server nahi chahiye) |
| Speed | Fast | Slow (users badhne par) |
| Use Case | Websites, Offices, Colleges | Ghar ka LAN, File Sharing |
| Maintenance | Easy (server update karo) | Hard (sabko update karo) |
| Dependency | Server pe depend karta hai | Koi ek point fail nahi hota |
Real Life Example:
Client-Server:
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College library: Ek librarian (Server), students (Clients)
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Students book maangte hain, librarian deta hai
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Librarian nahi hua to books nahi milengi
Peer-to-Peer:
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4 doston ka LAN game khelna
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Har kisi ke paas game hai
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Sab ek dusre se connect hoke game khel rahe hain
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Koi central system nahi
Summary:
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Client-Server ka use tab karo jab:
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Network bada ho (college, office, banking)
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Security aur control important ho
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Peer-to-Peer ka use tab karo jab:
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Chhota network ho
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Jaldi aur saste mein setup chahiye
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