|
|
Protocol Drivers
Networking API drivers must take API requests and translate them
into low-level network protocol requests for transmission across
the network. The API drivers rely on transport protocol drivers in
kernel mode to do the actual translation. Separating APIs from
underlying protocols gives the networking architecture the
flexibility of letting each API use a number of different
protocols. The protocol drivers that Windows 2000 includes are
Data Link Control (DLC), NetBEUI, TCP/IP, and NWLink, although
other protocols might be present as options, such as the AppleTalk
protocol installed with Services For Macintosh on Windows 2000
servers. Here's a brief description of each protocol:
DLC is a relatively primitive protocol that some IBM mainframes
as well as some Hewlett-Packard network printers use. It is a
"raw" protocol in the sense that no networking APIs can use it;
applications that want to use DLC must interface directly to the
DLC transport protocol device driver.
IBM and Microsoft introduced NetBEUI in 1985, and Microsoft adopted NetBEUI
as the default protocol for LAN Manager and the NetBIOS API.
Microsoft has since enhanced NetBEUI, but the protocol is
limited because it's not routable and performs poorly on WANs.
NetBEUI (NetBIOS Extended User Interface) was so named because
it is tightly integrated with the NetBIOS API, but the protocol
Microsoft's NetBEUI protocol driver implements is NetBIOS Frame
(NBF) format. Windows 2000 includes NetBEUI solely for
interoperability with legacy Windows systems (Windows NT 4 and
Consumer Windows).
The Internet's explosive growth and reliance on the TCP/IP
protocol has made TCP/IP the preeminent protocol in Windows
2000. The Defense Advanced Research Projects Agency (DARPA)
developed TCP/IP in 1969 specifically as the foundation for
the Internet; therefore, TCP/IP has WAN-friendly
characteristics such as routability and good WAN performance.
TCP/IP is the preferred Windows 2000 protocol and is the only
one installed by default.
NWLink consists of Novell's IPX and SPX protocols.
Windows 2000 includes NWLink for interoperability with Novell
NetWare servers.
|
|
|
