NetWare is a network operating system (NOS) that provides transparent remote file access and numerous other distributed network services, including printer sharing and support for various applications such as electronic mail transfer and database access. NetWare specifies the upper five layers of the OSI reference model and, as such, runs on any media-access protocol (Layer 2). Additionally, NetWare runs on virtually any kind of computer system, from PCs to mainframes.NetWare was developed by Novell, Inc., and was introduced in the early 1980s. It was derived from Xerox Network Systems (XNS), which was created by Xerox Corporation in the late 1970s, and is based on a client-server architecture. Clients (sometimes called workstations) request services, such as file and printer access, from servers.As with other network addresses, Novell IPX network addresses must be unique. These addresses are represented in hexadecimal format and consist of two parts: a network number and a node number. The IPX network number, which is assigned by the network administrator, is 32 bits long. The node number, which usually is the Media Access Control (MAC) address for one of the system's network interface cards (NICs), is 48 bits long.