Computer Networks Notes
Subject Overview
Computer Networks covers network architecture and reference models (OSI, TCP/
Subject at a glance
3
Units
25
Topics
4
Credits
3
Infographics
Unit-wise Syllabus
3 units — open any unit for detailed topic-wise notes, diagrams and important exam questions
- Uses
- goals and applications of computer networks
- network structure and architecture
- OSI and TCP/IP reference models and their comparison
- static and dynamic channel allocation
- ALOHA protocols
- CSMA and CSMA/CD
- collision-free protocols
- networking devices (repeaters, bridges, routers, gateways, switches)
Repeater
Physical
Regenerates signals
Hub
Physical
Broadcasts to all ports
Bridge / switch
Data link
Forwards by MAC address
Router
Network
Forwards by IP address between networks
Gateway
All layers
Connects different protocols
Study guide
This unit covers the uses and goals of networks, architecture, the OSI and TCP/IP models and their comparison, channel allocation, ALOHA, CSMA and CSMA/CD, collision-free protocols and networking devices. Learn the layers and devices in one table.
- FDDI
- Fast Ethernet
- HIPPI
- Fiber Channel
- IEEE 802.x standards
- static vs dynamic routing and routing algorithms
- causes of congestion and congestion control strategies
Routes set
Manually by the admin
Automatically by protocols
Adapts to failure
No
Yes
Overhead
None
Uses bandwidth and CPU
Examples
Small networks
RIP, OSPF, BGP
Study guide
You study FDDI, Fast Ethernet, HIPPI, Fibre Channel, IEEE 802 standards, static and dynamic routing and algorithms, congestion causes and control. Practise a shortest-path routing example.
- Principles of internetworking
- connectionless internetworking
- Internet protocols and IPv6
- security requirements and attacks
- encryption
- public key encryption and digital signatures
- distributed applications — SNMP
- SMTP
- HTTP
Confidentiality
Threat: eavesdropping
Integrity
Threat: modification
Authentication
Threat: spoofing
Availability
Threat: denial of service
Non-repudiation
Digital signatures
Study guide
You study internetworking, connectionless internetworking, IPv6, security requirements and attacks, encryption, public key and digital signatures and applications such as SNMP, SMTP and HTTP. Understand how public key encryption secures web traffic.
Why Computer Networks Matters
Networking and network security are core to IT infrastructure and cybersecurity careers and to CCNA-type certifications.
How to Prepare for Computer Networks
- Practise routing and subnetting problems.
- Use a network simulator to try configurations.
- Learn protocol names and their layers.
Computer Networks: Frequently Asked Questions
What is IPv6?
IPv6 is the newer Internet Protocol with 128-bit addresses, designed to replace IPv4 as addresses run out.