Chapter 1 Introduction to Computers and C Programming

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CS 56

• Networking Essentials

Chapter 4 Survey of Network Operating Systems
Sonny Huang
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Chapter 4 Survey of Network Operating Systems

• Outline
• Introduction
• Novell Operating Systems
• Microsoft Network Operating Systems
• Other Network Operating Systems
• NOS in Multivendor Environments

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Introduction to Network Operating Systems

• Overview
• A. Some networking software can either be added
  to the computers own operating system or
  integrated with it.
• 1. Novells NetWare is added to each clients
  existing operating system.
• 2. NOS software is integrated into several client
  operating systems including Windows 2000
  Professional, Windows NT Workstation, Windows 98,
  Windows 95, and AppleTalk.
• B. Operating System Considerations
• 1. Operating systems coordinate computer
  operations and applications.
• 2. Applications are written to specific operating
  systems.

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Introduction to Network Operating Systems

• C. Coordinating Hardware and Software
• 1. OS controls how the following hardware
  resources are used and allocated
• a. Memory
• b. CPU time
• c. Disk space
• d. Peripheral devices
• 2. Network and client operating systems are
  coordinated.
• a. Servers provide resources to the network
  clients.
• b. Client network software makes these resources
  available to the client computer.

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Introduction to Network Operating Systems

• D. Multitasking
• 1. Provides the means for a computer to process
  more than one task at a time.
• 2. A computer must alternate between tasks if it
  has only one processor.
• 3. Preemptive OS preempts or takes control of
  the processor sharing without tasks cooperation
  (Windows 95 and Windows NT).
• 4. Non-preemptive Cooperative processor is
  never removed from a task. Task decides when to
  given up processor (Windows 3.x).
• 5. Preemptive best for networking.
• 6. True multitasking OS can run as many tasks as
  there are processors.

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Introduction to Network Operating Systems

• When necessary, the preemptive system can
  shift CPU activity from a local task to a network
  task.
•  
• Software Components
• A. NOS Software
• 1. Network server ties network together.
• a. Connects all computers and peripherals.
• b. Coordinates the functions of all computers
  and peripherals.
• c. Provides security by controlling access to
  data and peripherals.
•  

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Introduction to Network Operating Systems

• Elements or components of computer operating
  systems are said to interoperate when they can
  function in different computer environments.
•  
• 2. Two major components of network software
• a. Installed on clients
• b. Installed on servers

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Introduction to Network Operating Systems

• Client Software
• 1. Redirector
• a. Allows access to nonlocal resources.
• b. The redirector intercepts requests in client
  computer.
• c. Determines whether redirector should work
  with local or network resource.
• d. A server processes the clients requests for
  network resources.
•  
• Redirector is also
• referred to as the shell
• or the requester
• depending on the NOS.
•  

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Introduction to Network Operating Systems

• 2. Designators
• a. Drive mapping is the assignment of a letter
  or name to a disk drive so that the operating
  system or network server can identify and locate
  it.
• b. Windows NT uses Explorer to connect or map
  network drives.
•  
• Twenty-six drive letters (A-Z) can be assigned.
•  
• Peripherals
• a. Redirector can intercept calls to printer
  port and redirect to a print server.
• b. LPT or COM can refer to network printers
  instead of local printers.

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Introduction to Network Operating Systems

• c. Users do not need to be concerned with the
  actual location of data or peripherals.
•  
• Redirector sends requests to either computers or
  peripherals.

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Introduction to Network Operating Systems

• Server Software
• 1. Purpose
• a. Allows others access to servers resources.
• b. Windows NT and Windows 95 have both client
  and server software.
• 2. Resource Sharing
• a. NOSs allow sharing and determine degree of
  sharing.
• b. Give different users different levels of
  access to resources.

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Introduction to Network Operating Systems

• c. Ensure that two users do not use same
  resources simultaneously.
• 3. Managing Users
• a. NOSs make it possible for network
  administrators to determine which users can use
  the network.
• b. The network administrator can
• (1) Create users and their privileges, which
  are tracked by the network.
• (2) Grant or deny user privileges.
• (3) Remove users.
• c. NOSs allow for the creation of user groups.

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Introduction to Network Operating Systems

• 4. Managing the Network
• a. Advanced NOSs include management tools to
  help administrators keep track of network
  behavior.
• b. Management tools can detect signs of trouble
  and present these in a chart, or other format.

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Introduction to Network Operating Systems

• Choosing a Network Operating System
• A. Planning decisions must take into account the
  services and resources expected or required of
  the network.
• B. Determine network architecture first Client
  server or peer-to-peer.
• C. Server-based networking allows inclusion of
  security capabilities well beyond those available
  to a peer-to-peer network.
• D. Determine the kinds of interoperability
  necessary for the network as a whole.
• E. It is not uncommon to find both network
  architectures in a single network(network service
  on the server and network client application on
  each computer).

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Introduction to Network Operating Systems

• F. Major server-based NOSs include Microsoft
  Windows 2000 Server, Microsoft Windows NT 4, and
  Novell NetWare 3.x, 4.x and 5.x.
• G. Major peer-to-peer NOSs include AppleTalk,
  Windows 95 and 98, and UNIX (including Linux and
  Solaris).
•  
• c04dem01 video shows introductory discussion of
  NOSs.

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Novell Operating Systems

• Introduction to NetWare
• A. NetWare is often the NOS of choice in mixed
  operating system environments.
• 1. NetWare NOS consists of a server and client
  applications.
• 2. Server application can be accessed from
  computers running MS-DOS, Microsoft Windows
  (versions 3.x, 95, 98, and NT), OS/2, AppleTalk,
  or UNIX.
• B. Novell Directory Services (NDS) provides name
  services as well as security, routing, messaging,
  management, Web publishing, and file and print
  services.

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Novell Operating Systems

• 1. NDS is an X.500 directory architecture that
  organizes all network resources, including users,
  groups, printers, servers, and volumes.
• 2. NDS provides single-point logon for the user.
• NetWare Services
• A. File Services
• 1. NetWare file services are part of the NDS
  database.
• 2. The entire network can be viewed in a format
  that is native to the individual workstation
  operating system.

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Novell Operating Systems

• B. Security
• 1. Logon security provides authentication
  verification based on user name, passwords, and
  time and account restrictions.
• 2. Trustee rights control which directories and
  files a user can access and what the user is able
  to do with them.
• 3. Directory and file attributes identify the
  actions that can be carried out on a file
  (viewed, written to, copied, made shareable or
  nonshareable, or deleted).

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Novell Operating Systems

• C. Printing Services
• 1. Printing services are invisible to the user
  of the client computer.
• 2. Print request from a client is redirected to
  the file server, handed off to the print server,
  and then to the printer.
• 3. Same computer can serve as both file server
  and printer server.
• 4. NetWare print services can support up to 256
  printers.

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Novell Operating Systems

• D. Sending Messages to Others
• 1. Users can send short messages to other users
  or groups on the network.
• 2. Message Handling Service (MHS) can be
  installed on any server and configured for a
  fully interconnected message infrastructure for
  e-mail distribution.
• Interoperability
• A. Full NOS interoperability is not always
  possible.
• B. Microsoft developed NWLink and Gateway
  Services for NetWare (GSNW) to allow Windows NT
  domain clients access to resources or services on
  the NetWare network.

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Microsoft Network Operating Systems

• Introduction to Windows NT
• A. Windows NT combines the client and network
  operating systems in one.
• 1. Windows NT Server configures a computer to
  provide server functions and resources to a
  network.
• 2. Windows NT Workstation provides the client
  functions of the network.
• B. Windows NT operates on a domain model. There
  are four different domain models from which to
  choose
•  
• A domain is a collection of computers that
  share a common database and security policy.

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Microsoft Network Operating Systems

• 1. Single-domain A single server maintains the
  security and accounts database.
• 2. Single-master A single master network may
  have several domains, but one is designated as
  the master and maintains the user-accounts
  database.
• 3. Multiple-master A multiple master network
  includes several domains, but the accounts
  database is maintained on more than one server.
  This model is designated for very large
  organizations.
• 4. Complete-trust A complete trust means there
  are several domains, but no single domain is
  designated as a master. All domains completely
  trust each other.

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Microsoft Network Operating Systems

• Video Note c04dem02, c04dem03, c04dem04,
  c04dem05 and c04dem06 videos show an illustrated
  overview of a domain model NOS.
•  
• Windows NT Services
• A. File Services
• 1. MS-DOS (16-bit) FAT (File Allocation Table)
• a. Supported by MS-DOS, Windows 95 and 98,
  Windows NT and Windows 2000.
• b. Publicly share a directory to the network and
  set the attributes of the data (No Access, Read,
  Change, or Full Control).

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Microsoft Network Operating Systems

• 2. MS-DOS (32-bit) FAT (File Allocation Table)
• a. Supported by MS-DOS, Windows 95 version C,
  Windows 98 and Windows 2000, but not by Window
  NT.
• b. Publicly share a directory to the network and
  set the attributes of the data (No Access, Read,
  Change, or Full Control).
• 3. Windows NT file system (NTFS)
• a. Supported only by Windows NT and Windows
  2000.
• b. When running in MS-DOS mode, NTFS directories
  will be unavailable.
• c. Enhanced security over FAT. Assigned
  directory-level and file-level permissions.

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Microsoft Network Operating Systems

• B. Security
• 1. Windows NT provides security for any resource
  on the network.
• 2. Windows NT network domain server maintains all
  the account records and manages permissions and
  user rights.
• 3. To access any resource on the network, a user
  must have rights to complete a task and the
  permission to use the resource.

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Microsoft Network Operating Systems

• C. Printing
• 1. Any client or server can function as a print
  server in a Windows NT network.
• 2. Publicly share a printer and set the
  attributes (No Access, Read, Change, or Full
  Control).
• 3. Can install more than one printer to a
  machine.
•  
• In Microsoft terminology printer is the
  software interface between the application and
  the print device. The print device is the
  physical printer.

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Microsoft Network Operating Systems

• D. Network Services
• 1. Messenger Service Monitors the network and
  receives pop-up messages.
• 2. Alerter Service Sends notifications that are
  received by the messenger service.
• 3. Browser Service Provides a list of servers
  available on domains and workgroups.
• 4. Workstation Service Runs on a workstation and
  is responsible for connections to servers. This
  is also referred to as the redirector.
• 5. Server Service Provides network access to the
  resources on a computer.

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Microsoft Network Operating Systems

• Interoperability
• 1. Gateway Services for NetWare (GSNW) provides
  the gateway connection between a Windows NT
  domain and NetWare server.
• 2. Client Services for NetWare (CSNW) enables a
  Windows NT workstation to access file and print
  services on a NetWare server.
• 3. File and Print Service for NetWare (FPNW)
  allows NetWare clients to access Windows NT file
  and print services.
• 4. Directory Service Manager for NetWare (DSMN)
  integrates NetWare and Windows NT user and group
  account information
• 5. Migration Tool for NetWare converting from
  Netware to Windows NT.

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Other Operating Systems

• AppleTalk NOS
• A. AppleTalk is built into the Mac OS
• 1. Supports high-speed, peer-to-peer networking
  capabilities among Apple computers.
• 2. Provides interoperability with other computer
  and network operating systems.
• 3. AppleShare allows Apple computer users to
  share those resources with other Apple users who
  have been given the appropriate permission to
  access them.
• B. Apple IP
• 1. Using Apple IP, users of computers other than
  Apple can connect to resources on an Apple NOS.
• 2. Apple IP is Apples implementation of TCP/IP
  networking protocol.

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Other Operating Systems

• 3. Apple NOS can connect to other networks
  through services that are supplied by the
  manufactures of those other NOSs and that run on
  their network servers.
• C. AppleTalk Directory Services
• 1. AppleTalk employs features known as zones.
• 2. Zones are logical groups of networks and
  resources.
• 3. AppleTalk Phase 1 network consists of no more
  than one zone, while Phase 2 can have up to 255
  zones.
• Phase 1 and Phase 2 are incompatible, and cannot
  be easily supported on the same network wiring.

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Other Operating Systems

• D. Interoperability
• Apple and Windows can share and exchange
  information of productivities suites(spreadsheets,
  databases, word processors, and e-mail).
• AppleShare makes it possible for Apple computer
  users to share those resources with other Apple
  users who have been given the appropriate
  permission to access them.
• Apple NOSs can provide full networking
  capabilities to clients and to other NOSs.

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Other Operating Systems

• UNIX LANs
• A. General purpose, multitasking, multiuser
  operating system.
• B. Two popular versions are Linux and Sun
  Microsystems Solaris.
• C. UNIX LAN is usually composed of one central
  computer and multiple terminals for individual
  users.
• D. UNIX is highly adaptable to the client/server
  environment. It can be transformed into a file
  server by installing file server software.
• E. Clients on a UNIX host can be any other
  computer running UNIX, MS-DOS, OS/2, Microsoft
  Windows, or Macintosh (System 7 or 8). A file
  redirector will enable the workstation to store
  and retrieve Unix file as if they were in its
  native format.

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Other Operating Systems

• Banyan Virtual Integrated Network Services
  (Vines)
• A. Client/server architecture NOS derived from
  Xerox Corporations Xerox Network Systems (XNS)
  protocols.
• 1. Features messaging through integration with
  Banyans Intelligent Messaging and BeyondMail
  software.
• 2. StreetTalk Explorer is used in the creation
  and management of network services.

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Other Operating Systems

• B. Other Vines features
• 1. Client support for Window NT and Windows 95
  and 98
• 2. Banyan Intranet Connect, which provides remote
  client access with a standard Web browser
• 3. TCP/IP server-to-server software
• 4. Banyan Networker, a family of network storage
  products
• 5. Multiprocessor support for up to four
  processors

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Other Operating Systems

• Peer-to-Peer LANs
• A. Windows for Workgroups (Windows 3.11)
• 1. Windows 3.11 includes Windows 3.1 plus a
  peer-to-peer NOS, an e-mail application, and an
  appointment book application.
• 2. Group of computers connected through
  workgroups can share printers and disk files.
• 3. Only items designated as shares can be seen by
  other members.
• 4. Drive letter assigned to the shared directory
  and the redirector redirects the LPT port across
  the LAN to the correct printer.

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Other Operating Systems

• Windows for Workgroups is being phased out,
  but students should know how to incorporate an
  existing Windows for Workgroups network into a
  larger, more modern networking environment such
  as NetWare or Windows NT Server.
•  
• B. Windows 95 and 98
• 1. Work well as clients on Windows NT and NetWare
  LANs using the respective client (requestor)
  software.
• 2. Users cannot have full benefit of Windows NT
  security features.
• 3. Do not support NTFS file format.

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Other Operating Systems

• C. Warp Connect
• 1. Combines OS/2 Warp and WIN-OS/2 peer-to-peer
  networking capabilities.
• 2. Capabilities are similar to Windows for
  Workgroups.
• 3. Users can share applications, printers,
  modems, and files, without installing any special
  hardware.

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NOSs in Multivendor Environments

• Multivendor Environment
• A. Most networks today exist in multivendor
  environments.
• B. Problems arise when the network is running
  more than one NOS.
• The servers OS, the
• clients OS, and the
• redirector must all
• be compatible.
• D. Must find common
• anguage in which all
• computers can
• communicate.

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NOSs in Multivendor Environments

• 2. Implementing Multivendor Solutions
• A. Implement Solution at Client or Server End
• 1. Client solution is referred to as the front
  end.
• Server solution is referred to as the back end.
• Note Choice of solution depends on the vendors
  involved.
•  
• B. Client Interoperability
• 1. Key to establishing interoperability is the
  redirector.
• 2. Computer can have more than one redirector to
  communicate over a network with different network
  servers.

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NOSs in Multivendor Environments

• 3. Redirector handles only the packets sent in
  the language or protocol that it can understand.
• Redirector needs to be able not only to
  access resources, but also to share them.
•  

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NOSs in Multivendor Environments

• C. Server Interoperability
• 1. Another way to implement communications
  between a client and a server is to install
  communication services on the server.
• Communication services convert file formats.
• 3. Services for Macintosh allows Macintosh users
  to access resources on a Windows NT server.

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NOSs in Multivendor Environments

• 4. Note that the Macintosh user still follows
  standard Macintosh procedures and sees Macintosh
  icons.
•  
• Windows NT connects to Novell NetWare servers.
•  
• Vendor Options
• There are three major networking product vendors
  are
• a. Microsoft
• b. Novell
• c. Apple.

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NOSs in Multivendor Environments

• Each of these vendors provides utilities that
• a. Make it possible for its operating systems to
  communicate with servers from other two vendors.
• b. Help its servers recognize clients from the
  other two vendors.

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NOSs in Multivendor Environments

• Microsoft
• a. Has multiple redirectors built in so clients
  can access resources and share their resources.
• b. Redirectors are automatically implemented
  during the operating system installation.
• 2. Microsoft in a Novell Environment
• a. Windows NT Workstationbased client to a
  Novell NetWare 3.x or 4.x network requires either
  NWLink and Client Service for NetWare (CSNW) or
  Novells NetWare Client for Windows NT.

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NOSs in Multivendor Environments

• NWLink is the Microsoft implementation of the
  Internetwork Packet Exchange/Sequenced Packet
  Exchange (IPX/SPX) protocol.
• b. Windows NT Serverbased server to a NetWare
  network requires NWLink and Gateway Service for
  NetWare (GSNW).
• GSNW lets all clients on a Windows NT server
  access Novell file/print services. CSNW lets a
  single workstation access Novell file/print
  services. CSNW is the Microsoft implementation of
  a NetWare requester (Novells term for
  redirector).

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NOSs in Multivendor Environments

• c. Connecting a Windows 95based or Windows98
  based client to a NetWare network requires
  IPX/SPX and Microsoft CSNW networks.
• d. Microsoft Service for NetWare Directory
  Services (NDS) is client software for NetWare
  that incorporates support for Novell Network 4.x
  and 5.x Directory Services.

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NOSs in Multivendor Environments

• 3. MS-DOS Clients
• a. Server OS vendors provide utilities that
  allow access to their respective resources.
• b. All of these utilities can reside on an
  MS-DOS client, allowing access to resources from
  all three environments.
• Novell
• Novell servers recognize the following clients
  for file and print services. NetWare
  character-based clients running MS-DOS can
  connect to
• a. Novell NetWare servers.
• b. Windows NT server-based computers.

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NOSs in Multivendor Environments

• B. Windows NT clients running Novells NetWare
  requester and the Windows NT redirector can
  connect to
• a. Novell NetWare servers.
• b. Windows NT workstation-based and Windows NT
  server-based computers.
• C. Novell provides requesters for
• a. MS-DOS
• b. OS/2
• c. NetWare Client for Windows NT

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NOSs in Multivendor Environments

• 5. Apple
• a. Redirector for AppleShare networking is
  included with AppleTalk and provides file-sharing
  functions.
• b. AppleShare print server, which is a
  server-based print spooler.
• c. AppleShare networking software offers MS-DOS
  clients access to AppleShare file and print
  servers.
• d. LocalTalk personal-computer card contains
  firmware to control the link between the
  AppleTalk network and the personal computer.
• e. Services for Macintosh on Windows NT include
  AppleTalk Protocol versions 2.0 and 2.1,
  LocalTalk, EtherTalk, TokenTalk, and FDDITalk.