1. Chapter 11
Network Operations

2. Introduction Look at: Network Operating Systems (11.1)
Software Components of Networking (11.2)
Installing a Network Operating System (11.3)
Understanding Basic Network Services (11.4)

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
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. 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

37. 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

38. 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

39. 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

40. 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

41. 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

42. 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

43. 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

44. 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