Page 316 - DCAP403_Operating System

Unit 14: Windows 2000

messages to access files at the server. The system uses Printer messages to send data to a remote Notes
print queue and to receive back status information, and the Message is used to communicate with
another workstation.
The Network Basic Input/Output System (NetBIOS) is a hardware-abstraction interface for
networks, analogous to the BIOS hardware-abstraction interface devised for PCs running MS-
DOS. NetBIOS, developed in the early 1980s, has become a standard network-programming
interface. NetBIOS is used to establish logical names on the network, to establish logical
connections or sessions between two logical names on the network, and to support reliable data
transfer for a session via either NetBIOS or SMB requests.
The NetBIOS Extended User Interface (NetBEUI) was introduced by IBM in 1985 as a simple,
effi cient networking protocol for up to 254 machines. It is the default protocol for Windows 95
peer networking and for Windows for Workgroups. Windows 2000 uses NetBEUI when it wants
to share resources with these networks. Among the limitations of NetBEUI are that it uses the
actual name of a computer as the address, and that it does not support routing.
The TCP/IP protocol suite that is used on the Internet has become the de facto standard networking
infrastructure; it is widely supported. Windows 2000 uses TCP/IP to connect to a wide variety
of operating systems and hardware platforms. The Windows 2000 TCP/IP package includes the

simple network management protocol (SNMP), dynamic host-configuration protocol (DHCP),
Windows Internet name service (WINS), and NetBIOS support. The point-to-point tunneling
protocol (PPTP) is a protocol provided by Windows 2000 to communicate between remote-access
server modules running on Windows 2000 Server machines and other client systems that are
connected over the Internet. The remote-access servers can encrypt data sent over the connection,
and they support multi-protocol virtual private networks over the Internet.
The Novell NetWare protocols (IPX datagram service on the SPX transport layer) are widely used
for PC LANs. The Windows 2000 NWLink protocol connects the NetBIOS to NetWare networks.
In combination with a redirector (such as Microsoft’s Client Service for Netware or Novell’s
NetWare Client for Windows 2000), this protocol enables a Windows 2000 client to connect to a
NetWare server.
Windows 2000 uses the data-link control (DLC) protocol to access IBM mainframes and HP
printers that are connected directly to the network. This protocol is not otherwise used by
Windows 2000 systems.
The AppleTalk protocol was designed as a low-cost connection by Apple to allow Macintosh

computers to share files. Windows 2000 systems can share files and printers with Macintosh

computers via AppleTalk if a Windows 2000 server on the network is running the Windows 2000
Services for Macintosh package.
14.5.2 Distributed-Processing Mechanisms

Although Windows 2000 is not a distributed operating system, it does support distributed
applications. Mechanisms that support distributed processing on Windows 2000 include
NetBIOS, named pipes and mailslots, windows sockets, remote procedure calls (RPC), and
network dynamic data exchange (NetDDE).
In Windows 2000, NetBIOS applications can communicate over the network using NetBEUI,
NWLink, or TCP/IP. Named pipes are a connection-oriented messaging mechanism. Named
pipes were originally developed as a high-level interface to NetBIOS connections over the
network. A process can also use named pipes to communicate with other processes on the

same machine. Since named pipes are accessed through the file-system interface, the security

mechanisms used for file objects also apply to named pipes.
The name of a named pipe has a format called the uniform naming convention (UNC). A UNC
name looks like a typical remote file name. The format of a UNC name is __server name_share

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