III. Network Operating System (NOS)
The NOS provides the services not available from the client OS.
Novell NetWare
Netware is a family of LAN products with support for IBM PC-compatible
and Apple Macintosh clients, and IBM PC-compatible servers. Netware is a
proprietary NOS in the strict sense that it does not require another OS, such as
DOS, Window, Window NT, OS/2 Mac System 7, or Unix to run on a server. A
separate Novell product-portable NetWare for Unix-provides server support for
leading RISC-based Unix implementations, IBM PC-compatible system running
Windows NT, OS/2, high-end Apple Macs Running Macs System 7, and Digital
Equipment corporation (DEC) VAX’s running VMS.
NetWare provide the premier LAN environment for file and printer
resource sharing. It is widely installed as the standard product in many
organizations because it incorporates many of the ease-of-use features required
for sharing printer, data, software, and communication lines.
LAN Manager
LAN Manager and its IBM derivative, LAN Server, are the standard
products for use in CS implementation using OS/2 as the server OS. LAN
Manager/X is the standard product for CS implementation using Unix System V
as the server. Microsoft released its Advanced Server Product with Windows NT.
It was enhanced with support for the Microsoft network management services,
referred to as Hermes, and Banyan’s Enterprise Network Services (ENS).
Advanced Server is the natural migration path for existing Microsoft LAN
Manager and IBM LAN Server customers.
LAN Manager and Advanced Server provide client support for DOS,
Windows, Window NT, OS/2, and Mac System 7. Server support extends to
NetWare, apple Talk, UNIX, Window NT, and OS/2. Client workstations can
access data from both NetWare and LAN Manager Servers at the same time. LAN
Manager support NetBIOS and Named Pipes LAN communications between
clients and OS/2 servers. Redirection services are provided map files and printer
from remote workstation for client use.
Advanced Server also support TCP/IP communication. MS has added
TCP/IP support to LAN Manager and Advanced Server along with Net View and
Simple Network Management Protocol (SNMP) agents. Thus, the tools are in
place to provide remote LAN management for LAN Manger LANs. MS supported
IBM Net View 6000 for advanced Server management.
Advanced Server provides integrated support for processing and CS
applications. Existing support for Window NT, OS/2, UNIX, and Mac System 7
clients lets application, database, and communication servers run on the same
machine as the file and print server. This feature is attractive in small LANs. The
native OS support for preemptive multitasking and storage protection ensure that
these server applications do not reduce the reliability of other services.
IBM LAN Server
IBM has integrated the Novell NetWare product into environments where
both IBM LAN server and Novell NetWare are required. NetWare provides more
functional, easier-to-use, and higher-performance file and print services. In
environments where these are the only LAN function, NetWare is Preferable to
LAN Manager Derivatives. The capability to interconnect to the SNA world makes
the IBM product LAN Server attractive to organizations that prefer to run both
products. Most large organizations have department workgroups that required
only the services that Novell provides well but may use LAN sever for CS
applications using SNA services.
Banyan VINES
Banyan VINES provides basic file and print services similar to those of
Novell and LAN Manager.
VINES incorporate a facility called StreetTalk that enable every resource in
a Banyan enterprise LAN to be addressed by name. VINES also provides
intelligent WAN routing within the communications server component. These two
features are similar to the OSI Directory Services X.500 protocol StreetTalk
enables resources to be uniquely identify on the network, making them easier to
access and manage. All resources, including file services, users, and printers, are
defined as object. Each object has a StreetTalk name associated with it.
StreetTalk names follow a three-level hierarchical format:
item@Group@Oganization
For example, a user can be identified as jpp@ics@uplb. All network
objects are stored in a distributed database that can be accessed globally.
Novell’s NDS is similar to StreetTalk in functionality. However, there are key
differences. NDS can partition and replicate the database, which will generally
improve performance and reliability. NDS is X.500-compliant and enables
multiple levels of hierarchy.
StreetTalk support a fixed three-level hierarchy. The NDS architecture
offer more flexible but with corresponding complexity and StreetTalk is less
complex to manage. One advantage StreetTalk has over NDS is that StreetTalk
object can have unlimited attributes available for selection. To locate a printer
with certain attributes the command: Locate a color laser printer with A4 forms
on the 4th floor of the Main Library finds and uses the printer with the desired
characteristics.
SERVER PLATFORMS
VINES offers ISDN and TI support for server-to-server communications
over a WAN, as well as integration of DOS, Windows, OS/2, and Mac Clients.
VINES does not support NFS clients.
PC NFS, FTP and SMB
NFS is the standard file system support for Unix. PC NFS (available from
SunSelect) and FTP provide file services support from a Unix and Linux servers to
Window, OS/2, Mac, and Unix client. NFS lets a client mount an NFS host’s filing
system (or a part of it) as an extension of its own resources. NFS’s resource-
sharing mechanisms encompass interhost printing. The transaction among NFS
system traditionally ride across TCP/IP and Ethernet, but NFS work with any
network that support 802.3 frames. SunSelect includes instructions for adding
PC-NFS to an existing LAN Manager or Window for Workgroups network using
Network Driver Interface Specification (NDIS) Drivers. With the increasing use of
UNIX server for application and database services, there is an increasing
realization that PC NFS may be all that is required for NOS support for many
workgroups. This can be a low-cost and low-maintenance option because the
UNIX server is easily visible from a remote location. An open source product,
Server Massage Block (SMB), does the reverse of what FTP and PC NFS do:
provide file support from Windows servers to Unix Linux client. For Linux client,
SMB, also known as Session Message Block, NetBIOS, or LAN Manager Protocol
is called samba.