CHAPTER Major Network Functional Architectures

1. CHAPTER Major Network Functional Architectures

2. Chapter Objectives • Discuss the characteristics, features etc of Peer-to-peer and client-server networks • Discuss the emerging concept of thin-clients • Examine the network operating system in terms of the client and sever components • Provide an overview of the desirable characteristics of the server and client hardware

3. Chapter Modules • Peer-to-Peer Networks • Client-Server Networks • Server and Client Operating Systems • An Overview of Client and Server Hardware

4. Key Words • Peer-to-peer, client-server • User level security, resource level security • hard-resource and soft resource sharing • scope • file/folder level access control (client-server) • folder level access control (peer-to-peer)

5. MODULE Peer-to-Peer Network Architecture

6. Questions • What are the characterizing features of peer-to-peer architecture? • Name some application areas of peer-to-peer architecture? • What are the two different types of access controls that could be imposed on peer-to-peer networks? Focus on the networks that could be set up with Windows 9x and the Windows 2000 or the Windows XP Client operating systems?

7. Peer-to-Peer Configuration Workstation Workstation Printer • Share and share alike among peer stations • Absence of a server

8. Characteristics of a Peer-to-Peer Network • Simple and inexpensive • Each user • Manages his or her resources on workstation • User is also the administrator of his or her resources • Multi-user applications cannot be implemented • Limited potential for expansion in terms of applications

9. Security • Limited security • If an operating system such as Windows 9x is used for setting the peer-to-peer network • Uses FAT32 • Better Security • If an operating system such as Windows XP is used for setting the peer-to-peer network • Uses NTFS

10. Peer-to-Peer Implementation • Any number of computers can be connected as long as they are not used for multi-user applications • An example of a multi-user application is the SQL database application • Limiting factor • Narrow scope of directory implementation and peripheral sharing

11. Peer-to-Peer Sharing • Simple sharing of resources • Share • Files • Printers • Sharing an Internet connection • etc. • Simple messaging • Unsuitable for multi-user business applications • Limited number of connections and limited sharing

12. Windows XP Professional • File and printer sharing • A web server could also be run on an XP client • However, the connection is limited to only 10 concurrent users

13. Limitations in Windows • Windows XP • 10 concurrent users at any time • Windows Home Edition • 5 concurrent users at any time

14. Peer-to-Peer OS • Windows 7 • Windows Vista • Windows XP • Linux

15. Typical Peer-to-Peer Security Printer (Password) Folder (Password) Workstation (Name) Network

16. Peer-to-Peer Security • No administrator to administer the overall security of the network resources • Resources are independently administered by the user on each peer computer (client) • No centralized control on the resources

17. Operating Systems Supporting Peer-to-Peer Networking • Nearly all the client operating systems of today support peer-to-peer networking

18. Operating Systems Supporting Peer-to-Peer Networking • Support for peer-to-peer networking is built into the newer desktop operating systems • Windows 98/95/Me • Windows NT Workstation • Windows 2000 Professional • Windows XP Professional • Windows Vista • Windows 7 • Ubuntu Linux (Server and Client OS) • Fedora Linux • Macintosh OS • A network operating system per se is not required for implementing the peer-to-peer network

19. Peer-to-Peer Networks Peer-to-Peer Networks Windows 9X Windows NT Workstation Windows 2000 Professional Windows XP Professional Windows Vista Share-level access control User-level access control

20. Peer-to-Peer Networks Based on Windows 9x • Only share level access control is possible • Access to a resource such as a printer, for example, can be controlled based on passwords only and not based on user names • User level access control is not possible where access to the resources could be controlled based on user names • Each user may be given a different type of access to the resource

21. A Note on Windows NT, Windows 2000 and Windows XP • It is possible to configure peer-to-peer networks with Windows NT Workstation, Windows 2000 Professional, Windows XP Professional, and Windows 7 • Such networks offer better security compared to the same configured with Windows 95/98 • User-level access control is enforced in this case

22. File Systems • Windows • FAT32 • NTFS 5.0 • Linux • .ext2 • Mac OS • HFS – older version • HFS+ - Later version

23. Advanced Peer-to-Peer Networks(Windows 2000/XP Based) Printer (User) Folder (User) Workstation (User) Network

24. Peer-to-Peer Sharing of Hard and Soft Resources: An Example Printer (Password) Folder (Password) Share by accessing at location or copying to local station Workstation (Name) Share by attaching as a logical printer to local station Network

25. END OF MODULE

26. MODULE Client-Server Network Architecture

27. A Typical Client-Server Physical Architecture Server Printer File Server Application Server Thin-client Server Client Client Note: This is simply a physical client-server architecture.

28. Logical Client-Server Application Architectures • File server • Application server • Thin-client

29. Network Servers • Basic network operating system • DNS server • DHCP server etc.

30. Client-Server Network Architecture and Applications • The presence of a client-server physical network architecture does not necessarily imply that client-server applications are running on the network • Distinguishing between client-server physical network architecture and client-server applications is important • A client-server network physical architecture is required to support client-server applications

31. Client-Server Access Control • Possible to exercise control at the user level • Access control can be imposed based on user names • Different levels of access can be given to different users • Read and Write • Read Only etc.

32. Client Server Access Control On a Folder Server User1 R & W User2 R Tariff Client Client User1 User3 User2

33. Client-Server Characteristics • One or more servers are present • Server is the lifeline of the network • The server is optimized for performance • Higher level of security • User level and share level access control • Login password, station restrictions etc. • Architecture of choice for most business applications

34. The Scope • Networks based on powerful client-server operating systems can support a large number of users and workstations • Very large networks can be configured by linking smaller client-server network segments together • Active Directory based networks • Windows 2003 Server

35. Client-Server Network Application Architecture • File Server • Application server • Thin-Client

36. Functional Architectures Functional Architectures Peer-to-Peer Client-Server Share-Level Access Control File Server Thin-Client User Level Access Control Application Server

37. Physical and Application Architectures Server File Server Application Server Thin-client Server Printer Client Client

38. Factors Used in the Comparison of Architectures • Place of execution for application • Network traffic implications • TCO • Enforcing security • Software requirements • Server side • Client side

39. END OF MODULE

40. MODULE File Server Networks

41. File Server and Application Servers • File server is the simplest architecture • Application server is the more advanced architecture • Forms the core of the implementation of the client server technology • Thin-client is also an advanced architecture

42. Questions to be Asked • Place of execution for application • Network traffic implications • TCO • Enforcing security • Software requirements • Server side • Client side

43. Functional Features of a File Server Running a Database Depository of shared data, shared applications etc. Server Data files and application files Client Database search is performed on the client Processing of data data takes place at the client

44. Word Execution Alternatives Server Client Microsoft Word stored on logical hard disk (Shared application) Microsoft Word stored on local hard disk (Dedicated application)

45. File Server in a Nut Shell • The file server basically operates as one large shared storage space for the clients • Any client with the permission to access the resources on the file server can share folders etc. on the file server • In effect, the file server functions as a logical disk (network drive) as far as the client is concerned • Compared to a local disk, the difference is that the logical disk can be shared by other clients as well

46. The Logical Drive Concept Physically present on the client Shared storage from the server Physical Drive c: Logical or Network Drive f: Client Station Logical drive is physically located at the server.

47. File Server Characteristics • Shared data is stored on the server and brought to the client for processing • Shared application software are also stored on the server • Entire execution takes place at the client • Consequently, considerable network traffic is generated as the files are ported to the client for processing • Application server networks overcome this drawback by executing part of the application on the server

48. Some File Server Concerns • Powerful clients are necessary as the execution takes place at the client • Total Cost of Ownership (TCO) is high • More network traffic is generated

49. File Server Features • Advantage • Easy to set up • Disadvantage • Higher network traffic • Higher TCO

50. END OF MODULE