CT 1503 Network Operating Systems

1. CT 1503Network Operating Systems Instructor: Dr. Najla Al-Nabhan 2014

2. Course Overview

3. Course Instructor Course Website: http://fac.ksu.edu.sa/nalnabhan/course/

4. Course Syllabus • Course Syllabus • Aimed to impart • Network operating systems (NOS): • Definition, • tasks, • examples, • tools, • managing users’ accounts, • protocol setting, • and security.

5. Grading Overview • Homework Assignments: 10% • Quizzes: 15% • Class Participation: 5% • Mid-terms: 30% • Final Exam: 40% • One Quiz and/or tutorial per week, schedule will be announced soon

6. Lecture 1: Network Operating Systems (NOS) An Introduction

7. What is an Operating System? • 2 kinds of a software – Application Software • Word processors, database manager, compiler, web browser – System Software • Operating system itself • Bridges between the hardware and users

8. Functions of Operating Systems (OS) • Resource management • • Memory management • • Device management • – Printer • – Hard drive • – display • • Process management • • Processor management (CPU time )

9. Operating Systems (OS) : Examples

10. Why OS was Born? Batch processing – Resident Monitor, JCL, IOCS

11. Time Sharing Using Operating Systems

12. Operating Systems • An operating system (OS) is software that manages computer hardware and software resources and provides common services for computer programs. • Operating systems form an essential component of the system software in a computer system. Application programs usually require an operating system to function. • Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources.

13. Operating Systems • For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and will frequently make a system call to an OS function or be interrupted by it. • Operating systems can be found on almost any device that contains a computer—from cellular phones and video game consoles to supercomputers and web servers.

14. Operating Systems: Examples • Examples of popular modern operating systems include: • Android, BSD, iOS, Windows Phone, • Linux, OS X, QNX, • Microsoft Windows, and IBM z/OS. • All these examples, except Windows, Windows Phone and z/OS, share roots in UNIX.

15. Networks Operating Systems • Network operating system refers to software that implements an operating system of some kind that is oriented to computer networking. • For example, one that runs on a server and enables the server to manage data, users, groups, security, applications, and other networking functions. • The network operating system is designed to allow shared file and printer access among multiple computers in a network, • typically a local area network (LAN), a private network or to other networks.

16. Networks Operating Systems: Where to use? • NOS can be used in: • Routers, switches and hardware firewall. • PCs in Peer-to-peer networks • Client-server Architicture

17. Routers NOSs • Network operating systems can be embedded in a router or hardware firewall that operates the functions in the network layer (layer 3) of the OSI model. • Examples: • JUNOS, used in routers and switches from Juniper Networks, • Cisco IOS (formerly "Cisco Internetwork Operating System"). • TiMOS, used in routers from Alcatel-Lucent • VRP (Versatile Routing Platform), used in routers from Huawei • RouterOS, software which turns a PC or MikroTik hardware into a dedicated router • ZyNOS, used in network devices made by ZyXEL. • ExtremeXOS, used in network devices made by Extreme Networks. Also called EXOS. • Embedded Linux, in distributions like Openwrt and DD-WRT which run on low-cost platforms such as the Linksys WRT54G.

18. Peer-to-Peer NOSs • In a peer-to-peer network operating system users are allowed to share resources and files located on their computers and access shared resources from others. This system is not based with having a file server or centralized management source. A peer-to-peer network sets all connected computers equal; they all share the same abilities to use resources available on the network. • Examples: • AppleShare used for networking connecting Apple products. • Windows for Workgroups used for networking peer-to-peer windows computers. • Advantages • Ease of setup • Less hardware needed, no server needs to be purchased. • Disadvantages • No central location for storage. • Lack of security that a client/server type offers.

19. Client/Server NOSs • Network operating systems can be based on a client/server architecture in which a server enables multiple clients to share resources. • Client/server network operating systems allow the network to centralize functions and applications in one or more dedicated file servers. • The server is the center of the system, allowing access to resources and instituting security. • The network operating system provides the mechanism to integrate all the components on a network to allow multiple users to simultaneously share the same resources regardless of physical location.

20. Client/Server NOSs • Examples: • Novell NetWare • Windows Server • Banyan VINES • Advantages • Centralized servers are more stable. • Security is provided through the server. • New technology and hardware can be easily integrated into the system. • Servers are able to be accessed remotely from different locations and types of systems. • Disadvantages • Cost of buying and running a server are high. • Dependence on a central location for operation. • Requires regular maintenance and updates.

21. Quiz • next lecture