Networking and Security: Network operating system

Defination:

A network operating system (NOS) is a piece of software that controls a network and its message (e.g. packet) traffic and queues, controls access by multiple users to network resources such as files, and provides for certain administrative functions, including security.

Note 1: A network operating system is most frequently used with local area networks and wide area networks, but could also have application to larger network systems.

Note 2: The upper 5 layers of the OSI Reference Model provide the foundation upon which many network operating systems are based.

Source: from Federal Standard 1037C

NOS was also the name of a proprietary time-sharing operating system on the CDC 60-bit 6000 Cyber series mainframe computers; in the mid 1980s, NOS was replaced with NOS/VE on the 64-bit Cyber-180 systems. and

Network Operating System (NOS) is an operating system that includes special functions for connecting computers and devices into a local-area network (LAN) or Inter-networking. Some popular NOSs for DOS and Windows systems include Novell Netware, Windows NT and 2000, Sun Solaris and IBM OS/2. The Cisco IOS (Internet Operating System) is also a Network Operating System with a focus on the Internetworking capabilities of network devices.

Features

Some of the features of Network Operating System are:

Provide basic operating system features such as support for processors, protocols, automatic hardware detection and support multi-processing of applications
Security features such as authentication, authorization, logon restrictions and access control
Provide name and directory services
Provide file, print, web services, back-up and replication services
Support Internetworking such as routing and WAN ports
User management and support for logon and logoff, remote access; system management, administration and auditing tools with graphic interfaces
Clustering capabilities; fault tolerant and high availability systems

Misconception

A NOS is not the same as the networking tools provided by some existing OSs, Windows XP for instance. An NOS is an OS that has been specifically written to keep networks running at optimal performance. Some NOS you should know:

Windows platform: Windows NT, windows 2000 server, windows 2003 server, windows 2003 server R2 and the next generation Windows server - windows 2008 server...