Windows95 aims to right the networking wrongs of Windows 3.x with a new suite of management features
Barry Nance
Windows 3.x has made LAN administrators' lives miserable over the past few years. The 3.x versions of Windows aren't easily integrated into corporate LAN management infrastructures and don't provide system access interfaces to PC inventory and configuration information. Third-party LAN management products from vendors like Saber Software can't provide complete, open solutions to LAN management problems with Windows 3.x. With Windows95, Microsoft set out to provide an environment that would easily mesh with current and future LAN management technologies.
LAN management functions include taking inventory, monitoring traffic, detecting viruses, distributing softw
are, monitoring applications, metering software licenses, mapping the network, notifying administrators when errors occur (i.e., alerts), and creating trouble tickets for help-desk resolution. Remote access to the LAN management functions is a plus, as is the ability to globally modify workstation configuration files from a central site. Windows95 offers features, some built into Windows and some available as APIs for third-party LAN management software vendors, in almost all these LAN management categories.
Opening the Cache Register
Windows95 uses its Registry to store LAN management details. The operating system also provides programming interfaces that can present LAN-oriented Registry information in formats that LAN management products expect. The Registry is a hierarchically organized system file containing configuration information, driver settings, operating-system parameters, user option choices, and other data. The Registry takes the place of the Windows 3.x-style INI files, although Wi
ndows95 still keeps INI files around for backward compatibility with 3.x applications.
The heart of Windows95's new resource management features, the Registry supplies information about network hardware (both Plug and Play and legacy devices), authorization levels (i.e., permissions), user profiles, network protocols, installed software packages, recent backups, and shared resources (including drive letter mappings, printer queue preferences, and whether the workstation can act as a peer to share its resources with other PCs).
The information the Registry stores is exactly the kind of information LAN administrators need to manage LAN-attached, Windows-based PCs. To help administrators get at the information, Windows95 lets administrators remotely view and modify a PC's Registry through the LAN cable or through a dial-up telephone connection. For management through the LAN cable, Windows95 offers an RPC (remote procedure call) interface that LAN management products can use to access the Registry.
An administrator can even set (or reset) a Windows95 PC's configuration, including screen colors, from a central console.
If you have hundreds or thousands of PCs and you upgrade them to Windows95, you'll be able to set what Microsoft calls System Policies. With the System Policies editor or a third-party administrative tool, you set up configurations, restrictions, and other global corporate standards that you want to apply to all PCs. When a Windows95 PC logs on to the LAN, Windows95 looks on the network for the policies you've set up. Windows95 retrieves the administrator's policies from the network, applies those policies, and continues with the log-on process. An administrator can, for example, selectively remove system capabilities such as peer resource sharing from a group of PCs. People using those PCs then won't be able to make their hard disks publicly available.
Through user profiles stored in the Registry, Windows95 makes it possible for different people to share a pool of desktop c
omputers and see a consistent Windows configuration no matter which machine the person might use. With its user-level pass-through security features, Windows95 restricts the ability to make configuration changes to the LAN administrator and people specially designated by the administrator.
Windows95 software components (e.g., Plug and Play configuration manager, applications, operating-system shell, device drivers, and operating-system services) store system configuration information in the hierarchical structure of the Registry. A separate user-profiles structure within the Registry holds information about each person who uses the PC. Windows95 interfaces (e.g., RPC, SNMP, DMI, peer services, and backup services) allow over-the-wire access to the information in the Registry. The RPC interface enables remote access, the peer services interface controls resource sharing within the PC, and the backup services interface lets administrators perform remote backups of Windows95 PCs.
Plug and Play
To make installing and configuring new PC hardware components simple and almost foolproof, Plug and Play tracks system resources (e.g., DMA channels, IRQs [interrupt requests], base I/O addresses, and UMB [Upper Memory Block] use) as well as device-driver configuration settings. The Plug and Play configuration manager stores the information in the Registry.
For the new Plug and Play hardware you buy, the obvious benefit is quick, easy configuration. For LAN administrators, the Plug and Play information becomes a valuable source of inventory detail, detail that's available over the wire to LAN management software products.
SNMP, DMI, and CMIP
Different LAN management products accept over-the-wire resource information in different formats, using different protocols. Using the information stored in the Registry, interfaces built into Windows95 provide resource management information required by those different third-party LAN management products.
For management products expecting dat
a through SNMP, Windows95 includes an SNMP agent. SNMP is a popular Internet protocol for sending network management information from one computer to another. The Windows95 SNMP agent is patterned after the Windows NT SNMP agent and consists of a 32-bit Windows software module. Network management products such as Hewlett-Packard's OpenView and Novell's NMS (Network Management System) can accept data via SNMP. Windows95 can send the SNMP messages over the IPX transport layer or the TCP/IP transport layer.
Windows95 invokes a MIB handler, which converts the information in the Registry into MIB (Management Information Block) format, and the SNMP agent transmits the MIB data to the requesting remote management console. Because each LAN component can have a completely different MIB format, Windows95 needs a different MIB handler for each component. The MIB handler extracts data from the Registry, puts the data for that component into the appropriate format, and hands the data to the SNMP agent for transmiss
ion across the LAN cable. Microsoft claims that writing MIB handlers will be an easy programming task. At this writing, the MIB handler specification has not been completed.
DMI is an emerging standard for how LAN management products describe and control the components in a desktop computer. DMI doesn't address how the information crosses the LAN cable, but rather how the management products interface to and describe the PC components. Microsoft will supply a DMI SL (Service Layer) interface to the Registry. That interface will reformat information in the Registry into DMI's MIF (Management Information Format).
The DMI specification defines the contents of the MIF files produced by the component-level modules; describes the MI (management interface) through which software can issue commands to query, reset, or control components; provides an SL that implements the MI and directs the activities of the various DMI modules; and identifies the CI (component interface) that a LAN product vendor can u
se to provide querying and controlling access to its product. Not only can the CI respond to commands, but it can also generate event notifications (called alerts in some LAN management products). Microsoft supplies the SL; third-party vendors will have to supply the other pieces of DMI.
Microsoft is hedging on whether DMI support will appear in the initial release of Windows95. However, the company says you'll be able to get Windows95 DMI support by downloading Windows95 patches and updates from a variety of electronic sources (e.g., CompuServe) soon after the release of Windows95. The group of companies promoting DMI, called the DMTF (Desktop Management Task Force), have already created DMI software components for DOS, Windows 3.x, and OS/2 workstations.
An alternative management protocol that's part of the OSI standard, CMIP, won't appear in Windows95 at all. Microsoft says that a CMIP agent would consume a considerable amount of system resources (primarily memory and CPU), CMIP isn't in wide
use yet, and customers aren't asking for CMIP in Windows95.
Peer, Backup, and Other Services
LAN administrators complain that the peer-to-peer network operating system Windows for Workgroups has a cavalier attitude toward letting people share drives and printers. With Windows95, Microsoft lets administrators clamp down on indiscriminate sharing of drives and directories. A person using a Windows95 workstation might, for instance, want to make his or her entire local hard disk available to others on a read/write basis and thus avoid having to use a central file server to share files. Windows95 would prohibit the operation if the LAN administrator had previously set up peer sharing restrictions.
Even after the fact, an administrator can (from a central console) close files and delete existing peer connections that he or she finds inappropriate. Windows95 gives administrators virtually the same control over peer resource sharing that those administrators have over departmental file servers.
An enhanced version of the Windows for Workgroups NetWatcher module gives administrators remote control and management of peer resource sharing.
Windows95 includes backup agents for Cheyenne's ARCserve and Arcada's Backup Exec. A backup agent is a specially designed peer sharing function that makes a workstation's files available, just for backup purposes, across the LAN. The backup agents give administrators the ability to make copies of a workstation's files via a central backup scheme. Cheyenne and Arcada, for their part, have announced they'll modify their products to interface with the backup agents in Windows95.
Backup agents are bidirectional in the sense that remote software distribution and installation can occur through the backup agent interface. With yet-to-be-developed third-party software distribution utilities, administrators will be able to install or upgrade software on a workstation through the backup agent interface just by instructing the backup agent to pull files from a cen
tral file server. Windows95 also has provisions for configuring the installed software, including new program groups, icons, and application-specific entries in the Registry.
Windows95, at least in its initial release, won't offer the LSAPI (Licensing Services API) developed by Brightwork, DEC, Gradient Technologies, Microsoft, and Novell. However, future versions of Windows will likely contain LSAPI components, according to Microsoft. The LSAPI will let LSAPI-enabled applications software products monitor and control the number of concurrently-in-use instances of those applications. Through the LSAPI, an application can register itself with a license server. When run on a workstation, the application asks the license server if the license agreement recorded in the license server permits another instance of the application to run.
People often perceive a response-time or performance problem at their workstations. Windows95 includes a Performance Monitor module that administrators can use to see
the types and categories of resource use occurring at a workstation in real time. An enhanced version of Windows for Workgroups' WinMeter utility, Performance Monitor can show a graph of, say, file I/O and CPU usage at a workstation. The administrator can run Performance Monitor at a central console, indicate which workstation to monitor and which statistics to graph, and then analyze that workstation's workload in real time.
The Costs of Resource Management
The resource management features of Windows95 are several orders of magnitude richer than those provided by earlier versions of Windows. If Microsoft is late and misses its announced release date of December 1994 for Windows95, a big part of the reason could well be the extra programming effort these new features require. Rob Price, program manager in the Personal Operating System Division of Microsoft, says, ``Microsoft wants Windows95 to be just another asset on your network that's simple to manage and well integrated.'' LAN administrators
know that's a tall order, one that isn't achieved overnight.
The new features, in the form of code modules on your hard disk, will naturally consume disk space. An upgrade to Windows95 will likely entail a hard disk housecleaning or purchase of bigger drives to accommodate the additional 35 MB that Windows95 requires.
As you load and run Windows95, you'll notice that these features--especially the new agent modules--use additional RAM, perhaps as much as 300 KB. You may need to buy additional memory for those workstations. And you may notice that workstations don't seem quite as peppy when running Windows95; the new features will need to use some CPU time to get their work done.
Perhaps the biggest cost of these new resource management features is the risk that not all third-party LAN management product vendors will embrace the new interfaces right away, or not all vendors will do so with bug-free software. The development of resource management drivers and utilities for Windows95 closely
parallels the Windows 3.x video driver development situation of a few years ago--you may recall that vendors took years to produce high-quality Windows 3.x video drivers.
You may, for instance, find yourself waiting for a new version of your preferred backup software that supports the Windows95 backup agent technology, or you may find that the hardware component vendors you deal with don't write Windows95 MIB handlers so that you can take advantage of the SNMP agent interface. Windows95 offers a lot of potential in the area of LAN management, but some time may pass before you can realize that potential in your organization.
The resource management interfaces and resource data organization that Microsoft has designed into Windows95 represent a strong reaction to the complaints from LAN administrators about Windows 3.x. If third-party vendors rise to the occasion--and early signs indicate that they will--Windows95 PCs will easily manage assets on a LAN. To take advantage of Windows95's new manage
ment features, a PC will likely need more RAM and more CPU power. However, the benefits of the rich set of Windows95's management facilities may well make the extra cost worthwhile.
Illustration: Windows95 Software Components
The Plug and Play configuration manager reflects hardware component settings in the central Windows95 Registry. Applications, the operating-system shell, drivers, and operating-system services also store information in the Registry. Through RPC, SNMP, and DMI agents, Windows95 makes the information in the Registry available to LAN management products. Administrators can restrict peer disk and printer sharing, and they'll be able to use third-party backup utilities that can make backup copies of workstation files as well as server files.
Illustration: The Registry editor lets you view and modify Windows95's central repository of resource management data.
Barry Nance is a BYTE contributing editor who has been a programmer for 20 year
s. He is the author of Using OS/2 2.1 (Que, 1994) and Client/Server LAN Programming (Que, 1994). You can reach him on the Internet or BIX at
barryn@bix.com
.
Windows Becomes LAN Friendly
