International Islamic University , Islamabad
Computer Networks (CS-501)
Part 1
Topics
1.Introduction and protocols architecture
2.Basic concepts of networking
3.Network topologies
4.Layered architecture
5.Physical layer functionality
6.Data link layer functionality
7.Multiple access techniques
1. Introduction and Protocols Architecture
Introduction
Definition: A computer network is a set of interconnected devices that can
communicate and share resources.
Benefits:
Resource Sharing: Printers, files, applications.
Reliability: Redundant paths and fault tolerance.
, Scalability: Easy to add new devices.
Communication: Email, instant messaging, video conferencing.
Data Management: Centralized data storage and access.
Protocols Architecture
OSI Model
Layer 1: Physical Layer: Deals with the physical connection between
devices and the transmission of raw bits over the medium.
Examples: Ethernet cables, fiber optics.
Layer 2: Data Link Layer: Provides error detection and correction, and
controls how data is placed on the medium.
Examples: MAC addresses, switches.
Layer 3: Network Layer: Handles logical addressing and routing of
packets across the network.
Examples: IP addresses, routers.
Layer 4: Transport Layer: Ensures error-free delivery of data with
mechanisms for error checking and data flow control.
Examples: TCP, UDP.
Layer 5: Session Layer: Manages sessions between applications.
Examples: NetBIOS, RPC.
Layer 6: Presentation Layer: Translates data between the application
and the network format.
Examples: Encryption, data compression.
Layer 7: Application Layer: Provides network services to applications.
Examples: HTTP, FTP, SMTP.
TCP/IP Model
Computer Networks (CS-501)
Part 1
Topics
1.Introduction and protocols architecture
2.Basic concepts of networking
3.Network topologies
4.Layered architecture
5.Physical layer functionality
6.Data link layer functionality
7.Multiple access techniques
1. Introduction and Protocols Architecture
Introduction
Definition: A computer network is a set of interconnected devices that can
communicate and share resources.
Benefits:
Resource Sharing: Printers, files, applications.
Reliability: Redundant paths and fault tolerance.
, Scalability: Easy to add new devices.
Communication: Email, instant messaging, video conferencing.
Data Management: Centralized data storage and access.
Protocols Architecture
OSI Model
Layer 1: Physical Layer: Deals with the physical connection between
devices and the transmission of raw bits over the medium.
Examples: Ethernet cables, fiber optics.
Layer 2: Data Link Layer: Provides error detection and correction, and
controls how data is placed on the medium.
Examples: MAC addresses, switches.
Layer 3: Network Layer: Handles logical addressing and routing of
packets across the network.
Examples: IP addresses, routers.
Layer 4: Transport Layer: Ensures error-free delivery of data with
mechanisms for error checking and data flow control.
Examples: TCP, UDP.
Layer 5: Session Layer: Manages sessions between applications.
Examples: NetBIOS, RPC.
Layer 6: Presentation Layer: Translates data between the application
and the network format.
Examples: Encryption, data compression.
Layer 7: Application Layer: Provides network services to applications.
Examples: HTTP, FTP, SMTP.
TCP/IP Model
