Chapter 7LAN Operating Systems

• LAN Software

• Software Compatibility

• Network Operating System (NOP) Architecture

• NOP Functions

• NOP Trends

LAN Software

• Network operating systems– Interface between hardware and application

software

• Application software: client front ends and server back ends or engines– Productivity software: e-mail, groupware etc.– Resource management software: security &

monitoring

Vertical Software Compatibility

• Common compatibility protocol

• Types– Server: hardware drivers, OS, network

operating system, DBMS, application back-ends, e-mail, groupware, distributed processing

– Client: hardware drivers, OS, network operating system, database front-end, query tools, application tools, groupware, other network applications, distributed processing front-end, user interfaces

Horizontal Software Compatibility

• Transparency between similar software layers between different client and servers

• Use middleware– Database middleware– Network operating system middleware– Operating system middleware– Distributed application middleware

NOP Architectures

• Peer-to-peer

• Client/server

• Current client/server

Peer-to-Peer NOSs

• Traditional NOSs: LANtastic or PowerLAN

• Printing & file sharing for less than 50 users

• Workstation as service requester (client) and/or service provider (server

• Lacking interoperability and scalability

Client/server NOSs

• Client software and server software: Netware3.12 and Microsoft LANManager

• Scalability, fast, reliability

• Lacking interoperability

Current Trend of NOSs

• Client NOSs: universal client• Server NOSs have performance characteristics

– NetWare for file and printing servers

– Windows NT, OS/2, UNIX for application servers

• Small business NOSs– High-quality file and printing sharing service

– DOS based, with minimal memory and disk requirement

– Easy installation, configuration, and management

– Dedicated 32-bit server software

– Bundled workgroup software (chat, e-mail)

– Easy migration to server-based NOSs

Client NOS

• Windows 95, OS/2 Warp Connect, Windows NT Workstation

• Functions– Operating system capabilities– Peer-to-peer networking capabilities– Client software to communicate with different

server network operating systems

Client NOS - OS Capabilities

• Desired characteristics– 32-bit OS– Preemptive multitasking– Protect memory space– Symmetrical multiprocessing (SMP)– Multithreading

• User interface: object-oriented, windows

Client NOS - OS Capabilities

• Application program support– Backward compatibility or legacy applications

(16-bit)– 32-bit applications

• Plug-n-play (PnP) features– PnP devices– PnP drivers– Reconfiguration

Client NOS - Peer-to-Peer Networking Capabilities

• File and printer sharing

• Workgroup application

Client NOS - Networking Capabilities

• Multiple servers

• Transfer protocols

• Remote access

• Laptop synchronization (with desktop)– Copy by date option: date range– Bidirectional option– Cloning option– Refresh option: existing files– Delta file synchronization: changes

Client NOS -Analysis

• Hardware/platform– Required-recommended memory– 16 or 32 bit– User interface

• Operating system capabilities

• Peer-to-peer networking capabilities

• Client networking capabilities

Sever NOSs - Types

• UNIX

• TCP/IP

• NFS

• NetWare

• Windows NT

UNIX

• Portability– Hardware platform– Application programs

• Modularity

TCP/IP

• Internet suite of protocols

• De facto standard for communication between heterogeneous network computers

NSF - Network File System

• Sun Microsystems

• Allows multiple different computing platforms to share files– Between NetWare and Windows NT– Between UNIX workstations, minicomputers,

and mainframe

NetWare

• Applications– File server– Printing server

• Global directory service: NetWare Directory Service (NDS)– Distributed– Replicated

Windows NT

• Applications– Web server– Database server– Application server

• Primary domain controller (PDC)– Domain directory service

Sever NOSs - Functions

• Directory service– Directory interoperability

• X.500

• Light-weight directory access protocol (LDAP)

• Microsoft’s open directory services interface (ODSI)

• Application services– Preemptive multitasking– 32-bit execution– Multithreaded application support– Program execution in protected memory space

Sever NOSs - Functions• File service

– System management– SQL– Mail & schedule– SNA gateway to IBM mainframe network

• Network clients services– DOS– Windows– Apple– OS/2– UNIX or NFS

Sever NOSs - Functions

• Network protocols supported– Multiprotocol routing

• Remote access and gateway service

• Management and administration service– Installation, configuration and administration– Integration and migration– Security: authentication, access rights– Audit trail and event logs– RAID

Sever NOSs Analysis

• Hardware/platform

• Installation and configuration

• Networking and connectivity

• Management and administration

Hardware/platform

• Min/max memory

• Min/max disk space

• CPUs

• Symmetrical multiprocessing

• Preemptive multitasking

• Multithreaded application support

• Program execution in protected memory space

Installation and Configuration

• Auto configuration

• No. of NIC drivers

Networking and Connectivity

• Clients supported

• Protocols supported

• Naming services

• Remote access

• E-mail gateway

• Web browser

• Messaging services

Management and Administration

• Central management

• SNMP for enterprise management

• Audit trails and event logs

• Security

• RAID

Server NOS Trends

• Symmetrical multiprocessing

• Clustering and fault tolerance

Assignment

• Review chapters 5-7

• Read Palmer: chapters 1-9

• Prepare exam 2