1. Operating Systems on the Network Approaches to managing network resources –Peer-to-peer model All the computers on the LAN have the same authority and each can act as a server to the other computers –Client/server model One or more computers control the resources for all computers on the network These servers require a network operating system (NOS) Also called the domain model

2. Example of a Peer-to-Peer Network

3. Example of a Network Operating System (NOS)

4. Operating Systems for the Client On a LAN, each PC must have an operating system that is capable of interfacing with a network interface card and the resources available on the network Options for a personal computer OS –Windows 9x (most popular) –Windows NT Windows NT Workstation Windows NT Server –Linux

5. Windows 9x Low-level; primarily used for personal computers Backward compatible with DOS, Windows 3.x, and legacy hardware devices Supports network access Can be used in a peer-to-peer or client/server network

6. Windows 9x

8. Windows NT Workstation Works well as a stand-alone OS or as an OS on a PC that is part of a peer-to-peer network or client/server network Like Windows 2000, does not support legacy software or hardware; expects hardware and software to follow the rules of relating to a true 32-bit OS

9. The Windows NT Desktop

10. Linux A scaled-down version of UNIX Small enough to run on a 486 computer, but has network capabilities similar to a full-fledged commercial version of UNIX Appropriate for –A small company environment with low-volume traffic for internet services –Internet-in-a-box devices –A web server or proxy server for a LAN

11. Largest Drawbacks to Using Linux Lack of support and standards Lack of application software written for it Lack of experienced technical people

12. An Operating System

13. The Shell and the Kernel Operating system kernel –Core portion of the OS that loads applications and manages files, memory, and other resources Operating system shell –Responsible for providing an interface for users to enter OS commands

14. Different Approaches to a Shell Windows –Uses a GUI shell as the default shell Linux and UNIX –Use a command-line shell as the default shell, and a GUI as an add-on feature

15. A Windows Shell

16. A Linux Shell

17. Network Operating Systems Reside on the controlling computer in the network Control software, data, and devices a user can access

18. Criteria to Consider When Selecting a NOC Reliability Performance Adaptability Ease of use and ease of installation Affordability Security Scalability

19. Popular Network Operating Systems Windows NT Server and Windows NT Enterprise Server Windows 2000 Netware by Novell UNIX and Linux

20. Windows NT Server and Windows NT Enterprise Server Designed to create and support a client/server network for a LAN called a domain One computer is designated the primary domain controller (PDC) –Server that controls a database of user accounts, group accounts, and computer accounts –Database is also called a directory database or security accounts manager (SAM) database Backup domain controller (BDC) –A server that contains a read-only copy of the domain database

21. A Windows NT Domain

22. Windows 2000 Includes four operating systems –Windows 2000 Professional –Windows 2000 Server –Windows 2000 Advanced Server –Windows 2000 Datacenter Server

23. Netware by Novell A popular NOS that can provide fast file and database access Uses a suite of protocols called IPX/SPX, which generally correspond to the TCP/IP protocols

24. UNIX Provides services over the Internet; can also support a LAN as a file and database server Used by 48% of today’s web servers on the Internet The accepted mainstay for the firewall market TCP/IP and Java were developed in a UNIX environment Several hardware manufacturers offer their own version of UNIX

25. Advantages and Disadvantages of UNIX Advantages –Highly reliable –Highly scalable –High performing –Powerful Disadvantages –Not easy to learn –Requires experienced, well-trained administrative and technical staff

26. Linux Originally an OS for a personal computer; fast becoming a viable option as a NOS Performs at about 40% of the speed of Windows NT Server

27. Network Services Wide range of possible network services Two primary services are printers and directory shares Others services include: –Groupware applications –Mail packages –Shared whiteboard applications –Web servers

28. Installing, Removing, and Configuring Network Services Driver or network itself provides network service Most NOSs have administrative tool for installing and removing network services Control network services in two ways: –Through global services administrative tool –Through console plug-in related to specific service –Add new tools under the Microsoft Management Console (MMC)

29. Network Bindings Process of linking network components from various levels of network architecture to ensure communication between them –Associates upper-layer services and protocols to lower-layer network adapter drivers Bind the most frequently used protocol, service, or adapter first to speed network connections

30. Network Printing Redirector intercepts printer requests and forwards them to print servers or network- connected printers Network printing involves installing printer –Some clients require local printer drivers –Others access printer drivers from print server New local printer points to print share

31. Printer Management Manage printers from local direct access or through network printer share; –Windows 2000/2003/XP lets you manage printers through Web browser Printer management includes: –Granting and restricting user access to printers –Monitoring print queue –Limiting access by time frame, department, or priority –Updating local and remote printer drivers –Maintaining printers; managing printers remotely

32. Sharing Fax Modems Feature not usually default component in NOS –Use third-party add-on product Once drivers are installed, manage and administer fax shares like printer shares

33. Network Directory Shares Let clients access and interact with storage devices on network Three ways to access shared directory: –Map unused local drive letter to directory share –Use UNC name to reference directory share –Select directory share from list of available shares Manage directory share by granting or restricting user access levels Linux uses either NFS or Samba to share files; NFS is the native Linux/Unix file sharing service whereas Samba is compatible with Windows systems

34. Network Applications Designed for multiple simultaneous users on numerous computers on network Three essential types of network application tools: –E-mail or messaging –Scheduling or calendaring –Groupware Easier to administer Poor network performance or limited bandwidth degrades application performance

35. Network Applications (continued) If network is down, application is unusable Three types of architecture for network applications: –Centralized – applications operate only on server –File-system sharing – application on client, but share database or storage directory –True client/server – some resides on server and some on client; group activities processed on server

36. E-Mail or Messaging Distributes messages across network or Internet –Internet mail standards include SMTP, POP3, and/or IMAP –See Simulation 8-1 for a visual explanation of how e-mail operates Includes many sophisticated abilities, such as attaching files, filtering, using distribution lists, and address book

37. E-Mail or Messaging (continued) Numerous e-mail protocols, including: –X.400 – hardware- and software-independent message-handling protocol –Internet Message Access Protocol (IMAP) – includes advanced message controls and fault tolerance –Message Handling System (MHS) – Novell standard similar to X.400

38. E-Mail or Messaging (continued) Numerous e-mail protocols, including: –Post Office Protocol, version 3 (POP3) – used by e-mail clients to download incoming messages –Simple Mail Transfer Protocol (SMTP) – current standard for Internet e-mail –X.500 – similar to X.400, but offers improved directory services

39. Scheduling or Calendaring Provides easy coordination of meetings and appointments Most offer private and public calendars, appointment books, task lists, and contact address books May offer reminders of special events Often integrated into e-mail programs May print daily, weekly, monthly, and yearly schedules

40. Groupware Lets multiple users interact simultaneously with single file, document, or project Most popular multiuser multimedia authoring tools include Lotus Notes, Novell’s GroupWise, and DEC’s TeamLinks Able to synchronize users and coordinate distributed data and activities PDA integration into groupware is exploding so that users can take their calendars and e-mail with them on a handheld