UNDERSTANDING THE OPERATION OF A NETWORK

1. UNIT 5: UNDERSTANDING THE
OPERATION OF A NETWORK

2. OUTLINE
• Network operating system setup
• Software components
• Installing windows 2000 server
• Networking printing
• The client/server environment

3. Network Operating Systems
• Network operating systems (NOSs) have existed for more than 30
years
• In the early 1980s, NOSs were mainly research projects
• Many of the original ones were actually a type of software package
added to standalone operating systems rather than a true NOS

4. Network Operating Systems
• The first networks allowed computers to exchange data by means of a
basic network protocol
• The application programs running on these computers controlled the
exchange of data and used the network to share data for specific
purposes
• One of the first successful attempts at integrating networking
extensions into an operating system resulted in Berkeley Unix also
known as BSD

5. Network Operating Systems
• As the networked computers increased, some type of uniform
networking support in the operating system would be necessary
• A user could only use a computer on which he or she had an account,
so users would want accounts on all computers
• In order to work collectively users had to move files back and forth
• This required they know each other’s passwords and manually track
the versions of the files

6. Network Operating Systems
• The first popular commercial network operating system was SunOS
• Two major improvements were present in SunOS:
• A network file system allowing a file that exists on one computer to be visible
from other computers
• A directory service

7. Network Operating Systems
• Some of the commonly available network
operating systems include:
• Linux
• Novell NetWare
• SunOS/Solaris
• FreeBSD
• Unix
• Windows

8. Network Operating Systems
• Current operating systems provide a large number of services to
provide application programs with a unified view of the network
• The basic functions of an operating system include:
• Directing and controlling activities of a computer’s hardware components
• Coordinating the interaction between software applications and computer
hardware

9. Network Operating Systems
• A network operating system utilizes device drivers as well as protocol
stacks for networking hardware
• Typically, there is at least one shared server providing access to files
and shared hardware resources
• It coordinates the activities of multiple computers across a network

10. Network Operating Systems
• The network operating:
• Advertises and manages resources from a
centralized directory
• Provides mechanisms to easily add and remove
services
• Reconfigures the resources
• Has the ability of supporting multiple services of
the same kind

11. Network Operating Systems
• Besides the mechanisms for supporting services, the NOS also needs
to draw as much power out of its hardware as possible
• One way of doing this is through a process called multitasking
• Multitasking is doing more than one thing at a time

12. Network Operating Systems
• There are two types of multitasking:
• Pre-emptive, where the processes are assigned CPU time slices by the
operating system
• Cooperative, where the operating system has no control over the processes
• When determining which operating system to use, preemptive
multitasking should be a key factor

13. Software Components of Networking
• Because a NOS provides a large variety of services and functions,
there are quite a few software components that help make up a
network operating system
• Some of those include:
• Naming and directory services,
• Client and server network software,
• Drivers and stacks

14. Software Components of Networking
• For the devices on the network to communicate, they use a special
interface card
• Before the card can be used, a software or device driver must be
installed on the computer
• A driver is a program that interacts with either a particular device or
type of software

15. Software Components of Networking
• Some of the driver technologies are:
• The Network Device Interface System (NDIS)
• Open Data-Link Interface (ODI)
• Win32 Driver model (WDM)
• Every NIC must have at least one protocol stack bound to it

16. Software Components of Networking
• A stack is a set of network protocol layers that work together
• The set of TCP/IP protocols that define communication over the
Internet is the most common stack
• TCP/IP stacks have been written for NDIS, ODI and WDM driver
interfaces

17. Software Components of Networking
• Client/server network operating systems allow the network to
centralize services and applications in one or more dedicated servers
• There is usually a clear distinction between client and server NOS
software
• Client software is a bit simple
• Server software is more complex and its implementation depends on
the type of NOS

18. Software Components of Networking
• The advantages of a client/server network include:
• Centralization
• Interoperability
• Scalability
• Flexibility
• Expense

19. Software Components of Networking
• The advantages of a client/server network include:
• Dependence
• Administration
• The client NOS makes network resources look to the user like they are
local

20. Software Components of Networking
• The server NOS provides the following functions:
• Manages a directory that contains user permissions to resources
• Supports file access compatible with various client operating systems
• Supports consistent user environment
• Provides interfaces to Internet Services
• Manages shareable mass storage

21. Software Components of Networking
• Some of the advantages and disadvantages of a peer-to-peer network
are:
• Less initial expense
• Setup
• Decentralization
• Security
• Performance

22. Software Components of Networking
• The most important component of a NOS is redirection
• Network operating systems depend heavily on redirection
• The redirector operates at the Presentation layer of the OSI model
and its function is to accept requests from applications and determine
whether network access is needed

23. Software Components of Networking
• Another process used by a NOS is a designator
• This works in coordination with the redirector and is associated with
drive mapping
• The client /server style is sometimes referred to as request/reply
architecture
• Many request/reply architectures are now being replaced by event-
driven, publish/subscribe architectures to achieve real item data
delivery

24. Installing a Network Operating System
• The installation of a NOS is a bit different than the installation of a
desktop operating system
• You will configure network services that determine the framework
for the rest of the network and clients
• Before the server operating system can be installed, there are some
decisions to make about how the computer will interact on the
network

25. Installing a Network Operating System
• Here are some additional considerations for a server:
• Function of the server
• File systems to be used
• Naming convention to be used
• Other operating systems and applications
• How data will be stored and protected
• Hardware compatibility

26. Installing a Network Operating System
• Here are come of the most common server uses:
• Logon server
• Network services server
• Application, File or Print server
• Web server
• FTP or News/Usenet (NNTP) server
• E-mail server

27. Installing a Network Operating System
• After you choose the server type, you must decide on a file system
• File systems are used to describe the operating system’s method of
organizing, managing and accessing files through logical structuring
on the hard drive
• File systems interact with the operating system to be sure that the
operating system can find files that are requested on the hard disk

28. Installing a Network Operating System
• The most common file systems are:
• FAT
• HPFS
• NTFS
• FAT stands for File Allocation Table
• It is simple, reliable, and uses little storage
• Virtual FAT (VFAT) is an enhanced version of the FAT file system

29. Installing a Network Operating System
• High-Performance File System (HPFS) was designed for the OS/2
operating system to allow for greater access to larger hard drives
• New Technology File System (NTFS) was developed expressly for
versions of Windows NT and Windows 2000
• NTFS is required to provide full security for a Windows file server, and
to support Macintosh datasets

30. Installing a Network Operating System
• A naming convention is a process by which names are created for the
workstations and servers on the network
• It is important to incorporate a scheme for user accounts, computers,
directories, network shares, printers, and servers so there is
uniformity and logical structure
• They should be descriptive enough to be able to locate devices
quickly, yet not have silly names

31. Installing a Network Operating System
• Determine how data will be stored and protected
• RAID organizes multiple disks into a large, high performance logical
disk
• There are many types of RAID:
• RAID Level 0
• RAID Level 1
• RAID Level 2

32. Installing a Network Operating System
• There are many types of RAID:
• RAID Level 3
• RAID Level 4
• RAID Level 5
• RAID Level 6
• RAID Level 10
• Not all operating systems support all versions of RAID

33. Installing a Network Operating System
• Microsoft publishes what' s called a Hardware Compatibility List (HCL)
which details compatible hardware for their operating systems
• Each operating system has minimum hardware requirements
• Although all NOSs have different installation steps, the basic process
is quite similar

34. Installing a Network Operating System
• Most NOSs are installed from a CD-ROM, but some can be installed
over the network if you have a shared directory and a network boot
disk
• There are setup logs created when a NOS is installed that can tell
what happened to cause the install to fail
• The cleanup procedure attempts to delete items that were partially
installed or left in an incomplete state

35. Installing a Network Operating System
• After the installation, the server needs to be configured for:
• DHCP scope(s)
• WINS
• DNS zones
• Once the operating system is installed and configured it must be kept
up to date
• A service pack is an update to an existing release

36. Introduction to Windows 2000 Server
• Windows 2000 Server serves as a redesign and enhancement of Windows
NT Server
• Windows NT was a popular NOS known for its intuitive graphical user interface
(GUI)
• Windows 2000 Server carries on many of the advantages of Windows NT
Server, plus provides additional features and capabilities (see next slide)
• Windows 2000 Advanced Server offers same benefits and features as
Windows 2000 Server, but adds support for clustering

37. Some Benefits of Windows 2000 Server NOS
• Advanced system of organizing and managing network
objects, called Active Directory
• Multiple, integrated Web services with easy to use
administrator interface
• Support for great deal of RAM and multiple processors
• Support for multiple, modern protocols and security
standards
• Excellent integration with other NOSs
• Simple, centralized management of multiple clients
• Flexible, customizable network management interface

38. Why Choose Windows 2000 Server?
• Windows 2000 Server is a popular NOS because it addresses
most of a network administrator’s needs very well
• Its customizable graphical administrative interface called, the
Microsoft Management Console (MMC), makes Windows 2000
Server a simple operating system to manage

39. Windows 2000 Server Hardware
• Important resource for determining what kind of Windows 2000 hardware
to purchase is Microsoft’s Hardware Compatibility List (HCL)
Table 8-2: Minimum hardware requirements for Windows 2000 Server

40. Windows 2000 Server Memory Model
Figure 8-8: Viewing virtual memory

41. Windows 2000 File Systems
• In addition to FAT, FAT32, and HPFS file systems, Windows 2000
Server supports other file systems, including:
• CDFS (CD-ROM File System)
• Used to read from and write to a CD-ROM disk
• Universal Disk Format (UDF)
• Another file system used on CD-ROM and DVD media
• NTFS (New Technology File System)
• Developed for Windows NT platform
• With release of Windows 2000, Microsoft updated NTFS to version 5

42. Installing and Configuring a Windows 2000
Server
Figure 8-18: Beginning with setup options

43. Installing and Configuring a Windows 2000
Server
Figure 8-19: Selecting Windows 2000 components

44. Installing and Configuring a Windows 2000
Server
Figure 8-20: Installing Components window

45. Initial Configuration
• After completing the Windows 2000 Server installation, the server is
not yet ready to support clients on a network
• First, the software must be configured
• For instance, to assign it a place in the domain

46. Establishing Users, Groups, and Rights
• The Guest account is a predefined user account with limited privileges that
allows a user to log onto the computer
• The Administrator account is a predefined user account that has the most
extensive privileges for resources both on the computer and on the domain
it controls
• A local account only has rights on the server they are logged onto
• A domain account has rights throughout the domain

47. Establishing Users, Groups, and Rights
Figure 8-21: User account password properties

48. Establishing Users, Groups, and Rights
• A domain local group is one that allows its
members access to resources within a single domain
• A global group allows its members access to
resources within a single domain
• A universal group is one that allows its members to
access resources across multiple domains and
forests

49. Establishing Users, Groups, and Rights
Figure 8-22: Creating a group

50. Establishing Users, Groups, and Rights
Figure 8-23:
The Program
Files Properties
dialog box

51. Internetworking with Other Network Operating
Systems
• Gateway Services for NetWare (GSNW)
• Acts as a translator between the Windows 2000 and NetWare client
redirector services
• Client Services for NetWare (CSNW)
• Can be installed on Windows 2000 clients to enable them to access NetWare
servers
• Directory Services Migration Tool (DSMIGRATE)
• Enables network administrators to migrate accounts, files, and permissions
from a NetWare NDS directory to the Windows 2000 Active Server Directory

52. Sharing Printers
Figure 8-5: Shared printers on a network

53. Sharing Printers
• All NOSs can:
• Create an object that identifies printer to rest of network
• Assign printer a unique name
• Install drivers associated with printer
• Modify printer attributes
• Establish or limit access to printer
• Remotely test and monitor functionality
• Update and maintain printer drivers

54. Sharing Printers
Figure 8-6: NetWare printer identification screen

55. Sharing Printers
• Printer queue
• Logical
representatio
n of printer’s
input and
output
Figure 8-7: Client issuing a job to a networked printer

56. Understanding Basic Network Services
• As the network configuration changes, the role of the server may
change
• Most NOSs have some type of administrative tool for removing or
adding services
• Often services depend on each other and stopping one can have a
detrimental effect on others

57. Understanding Basic Network Services
• Binding is the process of linking network components on different
levels to enable communication between the components
• Bindings are links that enable communication between network
adapter card drivers, protocols, and services
• Bindings establish a logical link between the upper protocols and
lower protocols on the NIC to provide interoperability

58. Understanding Basic Network Services
• The number of protocols run and the order of the bindings on the
client side can impact network performance
• The more protocols installed, the more network traffic
• The most frequently used protocol service or adapter should be
bound first

59. Understanding Basic Network Services
• With network printing, there are different operating systems, printer
languages, and various user or department requirements to meet
• There are three ways a printer can be networked:
• Connect via serial/parallel to a server
• Connect via serial/parallel to a remote print server
• Connect via an internal NIC

60. Understanding Basic Network Services
• Some factors to be considered when choosing a strategy for network
printing:
• Determine the connection speed
• Check the amount of RAM in the printer
• Be sure you have the proper amount of RAM
• It might be better to deploy several smaller printers rather than one large
printer
• Make sure that the printer, print server, and users are close to each other, if
possible

61. Understanding Basic Network Services
• The directory service is a database of service names and service
addresses
• Different operating systems have different techniques for doing this
• To ensure the directory service is not dependent on one computer,
the directory service is often replicated or mirrored

62. Understanding Basic Network Services
• Here is a summary of the features of directory services:
• A network service that identifies all resources on a network and makes them
accessible to users and applications
• Stores collection of information about objects that are name related
• Makes it easier to locate and manage network resources

63. Understanding Basic Network Services
• Two standards for using directory services over large networks such
as the Internet have been developed:
• X.500 directory service
• Lightweight Directory Access Protocol (LDAP)
• LDAP is now incorporated in most vendor releases of Linux

64. Understanding Basic Network Services
• Novell NetWare Directory Services (NDS) is an object-oriented
implementation of directory services that allows sophisticated
naming schemes and databases
• The NDS architecture provides access to all network resources
regardless of where the resources are physically located

65. Client-Server Environment
□ A network which consist of clients and servers.
□ A network architecture in which each computer or process on the network is
either a client or a server.

66. Server:
►Provides services for clients.
►Also known as host computer.
►Controls access hardware and software on the network.
►Provide storage area for programs, data and information.
► User authentication and registration.
►Provide access to stored data...

67. Client:
 Also known as users or customer.
 Request the resources from the server.
 Independent from other clients.
 Gets the files from server.
 Sends file to the server.
 Delete, copy, Rename the files on the server....

68. Types Of Servers:
• Application server:
• Dedicated to run different applications.
• Message Servers:
• Include chat rooms, group wares, provide instant and
real time communication between users.

69. Types of Servers Cont....
• Proxy Server:
• Used to filter request made by user over the server.
• Improves performance.
• Database Server:
• Manages database used over the network.

70. Types of Servers Cont....
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• W
eb Server:
• Provides access to internet via HTTP.
• Receives request from browser and sends
to main server....

71. Other Types of Servers.
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• FileTransfer Protocol Server (FTP)
• Mail Server
• Virtual Server
• Telnet Server
• News Server
• List Server

72. Advantages:
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►Reduces the volume of data traffic over the network.
► Provides faster response to clients.
►Allows the use of less powerful computers as clients
because most of the work is done by server.
► Provides more security.
► Accessible any time.

73. Disadvantages:
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► Expensive model.
► Operations stop across the network if server goes down.
► Need of professionals to maintain.
► No robustness.
► Difficult to implement than P2P.

74. Example:
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• Online Banking networks.
• User wants to access his account from the web browser. As his
data is stored in database, web server run a program to access
database.
• This database server may, in turn, fetch financial transaction
records from another database server.
• An application server interprets the returned data by following
the bank's business logic, and provides the output to the web
server.
• Finally, the web server sends the result to the web browser, which
interprets the data.

75. Comparison with P2P network
• Clients Server consist of many clients but P2P consist of one client one
server.
• Computing power, memory and storage is more than P2P.
• Scaled properly to perform any process on any query.
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