Network operating system (NOS): Software that (a) controls a network and its message (e.g. packet) traffic and queues, (b) controls access by multiple users to network resources such as files, and (c) provides for certain administrative functions, including security.

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

Some popular NOS's include:

• Windows NT
• IBM AIX
• Sun Solaris
• Plan 9 from Bell Labs
• Inferno
• Windows 2000 Server
• Windows Server 2003
• Novell NetWare
• Red Hat Linux

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 series and Cyber mainframes; in the mid 1980s it was replaced with NOS/VE on the 64-bit Cyber-180 systems.

See also

• Cisco IOS (formerly "Cisco Internetwork Operating System"), the operating system used on Cisco Systems routers and some network switches
• Windows Server 2003 R2, the most recent release of Microsoft's Windows Server platform/solution.
• Plan 9 from Bell Labs, a popular operating system developed for networks.
• Inferno, a popular operating system that can be hosted on other operating systems.
• Linux, used in approximately two thirds of web servers.

External links

• DMOZ: Network Operating Systems - editor-reviewed and categorized website links.

Operating systems | Network-related software

Network Operating System | ネットワーク・オペレーティング・システム | Network operating system