The term network operating system is used to refer to two rather different concepts:
A specialised operating system for a network device such as a router, switch or firewall.
An operating system oriented to computer networking, to allow shared file and printer access among multiple computers in a network, to enable the sharing of data, users, groups, security, applications, and other networking functions. Typically over a local area network (LAN), or private network. This sense is now largely historical, as common operating systems generally now have such features included.
Network operating systems can be embedded in a router or hardware firewall that operates the functions in the network layer (layer 3).
Examples:
JUNOS, used in routers and switches from Juniper Networks
Cisco Internetwork Operating System (IOS)
IPOS, used in routers from Ericsson
TiMOS, used in routers from Alcatel-Lucent
Versatile Routing Platform (VRP), used in routers from Huawei
RouterOS, software which turns a PC or MikroTik hardware into a dedicated router
ZyNOS, used in network devices made by ZyXEL.
Extensible Operating System used in switches from Arista
ExtremeXOS (EXOS), used in network devices made by Extreme Networks
Embedded Linux, in distributions like Openwrt and DD-WRT which run on low-cost platforms such as the Linksys WRT54G
Open source network operating system examples:
Cumulus Linux distribution, which uses the full TCP/IP stack of Linux.
Dell Networking Operating System (DNOS) is the new name for the operating system running on switches from Dell Networking; it will run atop NetBSD
Open Network Operating System (ONOS)
PicOS, Linux-based OpenFlow-supporting switching operating system from made by Pica8
VyOS, an open source fork of the Vyatta routing package
OpenSwitch Linux Network Operating System from Hewlett-Packard.
Early microcomputer operating systems such as CP/M, DOS and classic Mac OS were designed for one user on one computer. As local area network technology became available, two general approaches to handle sharing arose.
In a peer-to-peer network operating system users are allowed to share resources and files located on their computers and access shared resources from others. This system is not based with having a file server or centralized management source. A peer-to-peer network sets all connected computers equal; they all share the same abilities to use resources available on the network.
Examples:
AppleShare used for networking connecting Apple products.
LANtastic supporting DOS, Microsoft Windows, and OS/2 computers
Windows for Workgroups used for networking peer-to-peer Windows computers.
The advantages include:
Ease of setup
Less hardware needed, no server need be acquired
The disadvantages include:
No central location for storage
Less security than the client–server model
Network operating systems can be based on a client–server model (architecture) in which a server enables multiple clients to share resources. Client-server network operating systems allow networks to centralize functions and applications in one or more dedicated file servers. The server is the center of the system, allowing access to resources and instituting security. The network operating system provides the mechanism to integrate all the components on a network to allow multiple users to simultaneously share the same resources regardless of physical location.
Examples:
Novell NetWare
Windows Server
Banyan VINES
The advantages include:
Centralized servers are more stable.
Security is provided through the server.
New technology and hardware can be easily integrated into the system.
Hardware and the operating system can be specialized, with a focus on performance.
Servers are able to be accessed remotely from different locations and types of systems.
The disadvantages include:
Buying and running a server raises costs.
Dependence on a central location for operation.
Requires regular maintenance and updates.
