5. Concept of Computer Network and Network Security System

5.1 Introduction to Computer Networks and Physical Layer

• Networking Model, Protocols and Standards
• OSI Model and TCP/IP Model
• Networking Devices (Hubs, Bridges, Switches, and Routers)
• Transmission Media

5.2 Data Link Layer

• Services, Error Detection and Corrections, Flow Control
• Data Link Protocol
• Multiple Access Protocols
• LAN Addressing and ARP (Address Resolution Protocol)
• Ethernet, IEEE 802.3 (Ethernet), 802.4 (Token Bus), 802.5 (Token Ring), PPP (Point to Point Protocol)
• CSMA/CD
• IEEE 802.3 Standard
• Wireless LANs

5.3 Network Layer

• Addressing (Internet Address, Classful Address), Subnetting
• Routing Protocols (RIP, OSPF, BGP, Unicast and Multicast Routing Protocols)
• Routing Algorithms (Shortest Path Algorithm, Flooding, Distance Vector Routing, Link State Routing)
• Network Layer Protocols: ARP, RARP, IP, and ICMP
• IPv6 (Packet Formats, Extension Headers, Transition from IPv4 to IPv6, Multicasting)

5.4 Transport Layer

• The Transport Service, Transport Protocols
• Port and Socket, Connection Establishment & Connection Release
• Flow Control & Buffering, Multiplexing & De-multiplexing
• Congestion Control Algorithm

5.5 Application Layer

• Web (HTTP & HTTPS), File Transfer (FTP, PuTTY, Win SCP)
• Electronic Mail, DNS, P2P Applications
• Socket Programming, Application Server Concept
• Concept of Traffic Analyzer (MRTG, PRTG, SNMP, Packet Tracer, Wireshark)

5.6 Network Security

• Types of Computer Security, Types of Security Attacks
• Principles of Cryptography, RSA Algorithm
• Digital Signatures, Securing E-mail (PGP)
• Securing TCP Connections (SSL), Network Layer Security (IPsec, VPN)
• Securing Wireless LANs (WEP), Firewalls