Chapter 7 LAN 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: , 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, , 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, ) –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 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