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<META NAME="Author" Content="Steph Mineart">
<TITLE>Managing Multivendor Networks -- Ch 9 -- PC LAN Network Operating Systems</TITLE>
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<FONT COLOR="#000077">Managing Multivendor Networks</FONT></H1>
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<H1><FONT COLOR="#000077">- 9 -<BR>
PC LAN Network Operating Systems</FONT></H1>
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<UL>
<LI><A HREF="#Heading1">Novell NetWare</A>
<UL>
<LI><A HREF="#Heading2">Basic Architecture</A>
<LI><A HREF="#Heading3">Network Support</A>
</UL>
<LI><A HREF="#Heading4">Microsoft Windows NT Server</A>
<UL>
<LI><A HREF="#Heading5">Basic Architecture</A>
<LI><A HREF="#Heading6">Network Support</A>
</UL>
<LI><A HREF="#Heading7">NetWare/Windows NT Server Integration</A>
</UL>
<P>
<HR SIZE="4">
</P>
<P>As discussed in Chapter 8, "Services," PC LANs rely on a robust set
of services delivered to PC clients by designated server systems. Originally, PC
LAN servers only provided simple file and print services, but over time the role
of a PC LAN server has expanded to include application serving, database support,
transaction processing, and a variety of other client/server-related functions. In
many ways, the growing and expanding role of the PC LAN server is challenging the
traditional services offered by commercial midrange and mainframe computers.</P>
<P>Although a variety of vendors competed for the fledgling PC LAN market in the
1980s, one company managed to obtain the lion's share of the market--that company
was Novell. Novell's product, NetWare, ran on a dedicated PC and provided simple
file and print services to other PCs in the network. NetWare became widely popular
largely because it was one of the few products on the market that enabled you to
use whatever type of LAN you preferred--you could implement NetWare over ARCnet,
Ethernet, or Token Ring. Most of the other contemporary PC LAN products were tied
to specific LAN types or specific LAN adapters.</P>
<P>NetWare set the stage for the emerging PC LAN market by defining the capabilities
consumers expected out of a file and print server. Of course, no leading product
can stay unchallenged for long, and Novell's NetWare soon faced serious competition
from products offered by Banyan Systems (VINES), IBM (LAN Server and then OS/2),
and Microsoft (LAN Manager, Windows for Workgroups, Windows 95, and Windows NT).</P>
<P>The following is a quick overview of these four companies and their PC LAN products.
<UL>
<LI><I>Novell</I>. As the market leader, Novell set the stage for a long line of
PC LAN innovations that extend well beyond simple file and print services. Novell
designed the <I>NetWare Load Module (NLM)</I> to enable third-party companies to
write server-side NetWare applications and enterprise-oriented features, such as
fault tolerance and data recovery. In terms of scalability, Novell extended the power
and performance of NetWare by allowing other companies to port NetWare from its Intel-only
origin to high-end RISC systems, such as the HP9000. At the network level, the routing
capabilities and simple client configuration of Novell's IPX protocol suite enables
NetWare customers to easily construct networks of any size. Novell has further reinforced
the ease-of-installation and ease-of-maintenance of NetWare with the release of <I>NetWare
Directory Services (NDS),</I> a global directory structure for all NetWare resources.<BR>
<BR>
<LI><I>Banyan Systems</I>. Banyan Systems' <I>VINES (VIrtual NEtwork Software)</I>provides
file and print serving services similar to NetWare, but VINES runs with existing
network protocols, such as TCP/IP, SNA, and others. More significantly, VINES was
the first PC LAN product to support a network directory service, which Banyan named
<I>StreetTalk.</I> StreetTalk presents a single directory that encompasses multiple
servers and allows users to login only once to access multiple servers. Of course,
Novell later added its own network directory service in version 4.1 of NetWare, and
other network operating systems vendors are following suit. Banyan is, however, unbundling
StreetTalk, and offering it for other platforms, such as Windows NT.<BR>
<BR>
<LI><I>IBM</I>. IBM's original PC LAN product was the <I>LAN Server,</I> a dedicated
server product that shares the same protocol suite (NetBIOS/NetBEUI) and same overall
architecture as Microsoft's LAN Manager product. This should not be a big surprise
because IBM was one of the core developers of the NetBIOS/NetBEUI protocol suite
and the Server Message Block (SMB) architecture used by IBM, Microsoft, and others.
IBM's DOS -based LAN Server technology was then integrated into it's <I>OS/2</I>
server product. OS/2-based file and print servers have achieved a reputation for
stability and reli- ability; however, OS/2 servers tend to be implemented in sites
that have other IBM equipment--AS/400 and mainframes in particular.<BR>
<BR>
<LI><I>Microsoft</I>. Microsoft acquired most of its networking technology from 3Com
Corporation. Microsoft incorporated the 3Com technology in its main product lines,
starting with <I>LAN Manager,</I> a dedicated file and print server similar to IBM's
LAN Server offering. Microsoft then went on to extend its networking technology into
workgroup environments with the release of <I>Windows for Workgroups</I> and <I>Windows
95.</I> None of these Microsoft products offered the stability or performance of
a dedicated Novell NetWare server--but this changed with the advent of <I>Windows
NT Server.</I> Windows NT Server is an enterprise-oriented product that can compete
head-to-head with NetWare. Windows NT Server also offers additional features and
value--most notably, the capability to run on a wide range of platforms, fully integrated
support for TCP/IP, and support for a range of software products that enable an NT
Server to function as a full-blown application server.
</UL>
<P>The PC LAN products offered by all four of these vendors (Novell, Banyan, IBM,
and Microsoft) remain in use today, but two specific products are now competing to
dominate the modern market: Novell's NetWare and Microsoft's Windows NT Server. With
this in mind, the remainder of this chapter will focus on NetWare and Windows NT
Server.
<H2><A NAME="Heading1"></A><FONT COLOR="#000077">Novell NetWare</FONT></H2>
<P>As discussed previously, Novell pioneered the PC LAN network operating system
in the PC market. From a technology perspective, however, Novell offered few true
innovations in the area of file and print sharing--most of the concepts Novell implemented
were borrowed from other computer markets. For example, if you look closely you can
see that the original NetWare implementation bears a striking resemblance to Sun's
NFS implementation.</P>
<P>Although you can find fault with Novell's lack of technical innovation in its
early days, you certainly cannot fault Novell's marketing expertise. In the early
days of PC LANs, a number of companies--some big, some small--rushed products to
market to claim space in the exploding market. In all fairness, many of these products
offered technical features and functions superior to NetWare; however, none of the
companies behind those products could match Novell's marketing effort. Novell took
a solid, but hardly best-of-breed product, and leveraged it into a leadership position
through salesmanship and marketing savvy.</P>
<P>Of course, after Novell gained control of the market, they made major develop
investments in NetWare to shore up some of the technical inadequacies and insure
it's longevity in the market. One of the key early developments was the release of
a <I>System Fault Tolerance (SFT)</I> version of NetWare that addressed the data
protection/data recovery demands of large businesses.</P>
<P>Another early criticism of NetWare was that it was a <I>closed</I> operating system--you
had to run NetWare in a dedicated Intel-based system. Novell addressed this complaint
two ways. First, Novell licensed other companies to port NetWare to non-Intel systems,
such as high-performance UNIX systems. These systems were quite capable of running
both NetWare and other business applications concurrently. Second, Novell developed
an application environ-ment inside the NetWare server that permitted third-party
companies to write server-side programs. These programs are referred to as <I>NetWare
Load Modules (NLM)</I> and can handle system-oriented functions, such as tape backup
or application-oriented functions. When used in an application capacity, the server-side
component is typically part of a larger, client/server application.</P>
<P>Like any large, prosperous, and fast-growing company, some of Novell's new products
and new ideas were less than successful. For example, back in the early days of PCs,
when PC hardware was still quite expensive, customers demanded a non-dedicated version
of NetWare so they could also use the server system as a desktop system. Although
Novell did, in fact, come out with a non-dedicated version of NetWare, the implementation
was very awkward and desktop performance was so unpredictable that the product was
impractical to use in most environments.</P>
<P>Novell also proved itself capable of making mistakes on an even grander scale.
At one point Novell went through a phase of acquisition-mania, purchasing a broad
set of companies and products that had nothing to do with NetWare. The intent of
these acquisitions was for Novell to broaden its base beyond NetWare and to enter
the highly competitive (and lucrative) application suite market. During this phase,
Novell purchased high-profile products such as WordPerfect and Quattro Pro.</P>
<P>In addition to acquiring application-oriented products, Novell also acquired a
full-blown implementation of UNIX that it renamed UnixWare. At the time, Novell's
plan was to create a "SuperNOS" by merging NetWare and UnixWare. This SuperNOS
would enable Novell to better compete with the emerging Windows NT product as well
as with the ever-popular UNIX operating system.</P>
<P>Unfortunately for Novell, neither the application suite nor the SuperNOS strategy
panned out--Novell succeeded only in wasting millions of dollars and years of research.
Worse, Novell's lack of focus during this phase enabled Windows NT to penetrate deep
into Novell's file and print server market.</P>
<P>Since that time, Novell has divested itself of both the application and UNIX products
and has recommitted itself to enhancing NetWare on several fronts. On one front,
Novell has launched a Smart Global Network initiative. Under this initiative NetWare
services will be extended to the Internet and to other types of networks so NetWare
can become the central focus of networking in a heterogeneous environment. Additionally,
Novell's Net2000 initiative is targeted to establish an open set of APIs that will
permit users to access network services from non-NetWare platforms and help ease
the task of building distributed applications.</P>
<P>Novell has clearly realized that it is becoming rare for an enterprise to use
a single server operating system. With this in mind, Novell plans to integrate Microsoft,
HP, IBM, Sun, and SCO server platforms by making them all manageable via Novell's
NetWare Directory Services (NDS). NDS, introduced in NetWare 4.1, is a global directory
service that provides an organized, hierarchical structure for the administration
and management of network resources (in other words, users, file servers, shared
printers, and so on).</P>
<P>NDS offers a significant advantage over the older NetWare bindery. Under NDS,
the entire network appears to the end user as a single entity, and permits a single
log on to access all servers and shared network resources. Because the NDS structure
is replicated across servers, there is no single point of failure. The NDS naming
hierarchy can contain up to 15 levels of names (StreetTalk offers only a three-level
naming hierarchy). This allows for a great deal of flexibility, but also raises the
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