Peer LANs have matured into trustworthy tools. Here's how the top players--LANtastic, Microsoft Windows for Workgroups, Personal NetWare, and PowerLan--stack up.
Barry Nance
DOS-based peer-to-peer LANs have gotten a bad reputation among LAN administrators. Peer LANs can be fragile, because they use DOS as their underlying file-access mechanism. Furthermore, administrators view the indiscriminate sharing of workstation hard disks and directories with repugnance, because it lessens their control of system resources. Fortunately for administrators, peer LAN vendors are developing new OS/2- and Windows 95-based products that will eliminate the first objection (see the text box ``Peer into the Future''). And current versions of peer LAN products address the resource-sharing problem in different w
ays.
I tested four peer-to-peer NOSes (network operating systems): Artisoft's LANtastic 6.0, Microsoft Windows for Workgroups 3.11, Novell's Personal NetWare 1.0, and Performance Technology's PowerLan 3.11. I evaluated each for reliability, memory consumption, ease of use, price, security features, overall number and quality of features, and performance. The table ``Performance Benchmarks'' reports on file I/O benchmarks, while the table ``Features Comparison'' summarizes and contrasts product features.
A Jury of Peers
On a peer-to-peer LAN, my workstation can be your file server, your workstation can be my file server, and I can share your printer. The most significant practical limit for a collection of PCs sharing each other's hard disks is the lack of available drive letters for more than about 25 connections--the alphabet just isn't big enough. But peer LAN vendors encourage you to dedicate one or more PCs as servers when you grow to have more than 20 or 25 PCs attached to a LAN. For sma
ller LANs, you can use the peer LAN product in a strictly peer arrangement. You and I can share files without having to think of the file server as an intermediary. As the LAN grows, an unattended PC acts as a file server. You simply run the server component of the peer LAN product on that one PC and then connect only to the shared resources of the unattended PC. By not running the server component at the other (interactive) workstations, you regain some conventional memory.
I ran each of the peer NOSes under review through test suites that evaluate reliability, application compatibility, performance, and peer-to-peer communications. The reliability test concurrently copies 1000 files totaling 200 MB between several peer machines to test for file errors under peak-load conditions. All products passed this test without incident.
The compatibility tests check for compliance with DOS file-sharing conventions. All DOS applications issue DOS function calls to perform LAN file I/O. Certain functions (
e.g., create file, change directory, and delete file) behave the same on a LAN as they do on a local disk. Other functions (e.g., open file, read file, write file, and lock record) operate differently on a file server. If you open a file, and I try to open the same file for exclusive access, my operation should fail. Likewise, the LAN should allow two workstations to simultaneously open the same file if both specify shared access. The LAN should also let a workstation identify itself through the DOS function Get Machine Name. A NOS that passes these tests implements LAN specifications correctly and will work with Paradox, dBase, FoxPro, Lotus 1-2-3, Excel, Access, WordPerfect Office, and Microsoft Word, as well as any other application that uses LAN-aware DOS file I/O functions. All the peer LAN products reviewed satisfactorily implement these LAN characteristics.
The performance suite determines the LAN operating system's network file I/O performance by reading and writing files of random sizes. With
elapsed times of about half those of LANtastic and Personal NetWare, PowerLan easily outdistanced the competition. The final suite tests PC-to-PC communications using NetBIOS programming techniques; this test is significant because third-party LAN utilities, remote-control programs, and some E-mail packages talk PC-to-PC via NetBIOS. Again, all the products offer excellent NetBIOS connectivity.
I tested these NOSes on PCs equipped with SMC EtherCard Plus network adapters. The eight PC workstations and one unattended file server ranged from a 486/25 IBM PS/Valuepoint to a 486/66 Zenith Z-Station 500. For the benchmarks, I set up each product in its recommended optimum configuration. To measure the responsiveness of these peer network products, I used BYTE's low-level DOS benchmark program running concurrently on the eight workstations. The BYTE test measures file read and write operations at the DOS function-call level.
Artisoft's LANtastic
LANtastic has been a popular NOS for several years;
version 6.0, released in March 1994, adds many new features. LANtastic has offered Windows support since version 4.0, and the current incarnation supplies a network DDE function called Linkbook. Working between DDE clients and servers running on separate PCs, Linkbook does a good job of enabling applications to automate the sharing of document sections, spreadsheet rows, and other data. LANtastic's Windows interface makes print queue management, network management, E-mail, and other tasks as simple as pointing and clicking.
LANtastic offers a universal client feature that lets you connect LANtastic workstations to NetWare, LAN Server, and other server-based NOSes. In version 6.0, LANtastic is again adapter-independent. Beginning with version 4.0, you needed to buy a special version of the software at $99 per workstation if you wanted to use non-Artisoft network adapters. But in version 6.0, Artisoft reverts to a per-node pricing scheme that lets you use NDIS, ODI (Open Data-Link Interface), or Artisof
t's own drivers to access a network adapter not manufactured by Artisoft. A separate product from Artisoft lets Macintosh computers participate as workstations (but not servers) on the LAN. In addition, LANtastic's NetBIOS uses an IPX format for its LAN packets, letting you use popular IPX routers if you need to connect multiple LANs into a WAN.
Memory-wise, LANtastic 6.0 isn't as frugal as earlier versions were. But version 6.0 still needs only 45 KB in a workstation: 21 KB for NetBIOS, 6 KB for SHARE, and 18 KB for the Redirector module. The Server module adds 60 KB, for a total of 105 KB. All but the Server module can load high on a computer equipped with a 386 or better CPU, leaving 545 KB available for running DOS programs. Artisoft's ALONE program can turn a peer server into a dedicated resource, and the LANcache utility does a good job of caching both read and write operations for multiple drives. Neither the fastest nor the slowest NOS I tested, LANtastic came in third in the benchmarks.
Like PowerLan, LANtastic can recognize UPS (uninterruptible power supply) signals and shut down during power outages. It also comes with an easy-to-use E-mail application, Artisoft Exchange, that integrates post office names and addresses with the roster of LAN accounts, so you don't have to enter user names twice. You also get fax and pager communications, as well as a group scheduler.
You can set up as much security on a LANtastic network as you need. After creating each network user, you point and click to grant permissions and rights. You can password-protect disk drives, directories, or individual files. LANtastic can produce audit trails that track network activity. A server that is low on disk space or that is experiencing high CPU use can send warning messages to network administrators.
Artisoft hasn't forgotten LANtastic's simple-is-best roots. If you don't need the rich set of features LANtastic offers, you might want to investigate Artisoft's Simply LANtastic product. Simply LANtasti
c forgoes many features of the full LANtastic product to give you a basic, no-frills network environment for sharing files and printers. At the other end of the spectrum, Artisoft offers CorStream Server, a combination of LANtastic workstation software and NetWare 4.0 file server software.
Microsoft Windows for Workgroups
Performance enhancements make version 3.11 of Microsoft Windows for Workgroups a noteworthy upgrade of version 3.1, but the software continues to suffer from security shortcomings that keep it from being seriously considered by large organizations. Version 3.11 also improves greatly on the product's multiprotocol support. WFW installs easily, and you can connect WFW PCs to a NetWare network or an SMB-based network such as IBM's LAN Server.
WFW is a combination of Windows 3.1, a peer-to-peer NOS, an E-mail application, and an appointment book. The E-mail software is Microsoft Mail, and the appointment-book software is Microsoft Schedule+.
WFW runs best on a 386-, 486
-, or Pentium-based computer with at least 8 MB of RAM. On a lesser CPU chip or without sufficient memory, the software executes in Standard mode instead of 386 Enhanced mode. You can share files only if Windows is running in Enhanced mode.
Conventional RAM use isn't a meaningful measurement in the WFW environment, because the software shares files only when Windows is running, and Windows loads some of the WFW drivers in extended memory.
An optional Workgroup Connection for DOS package consists of DOS-only software. Workgroup Connection for DOS lets PCs that can't or don't run Windows access resources shared by computers that are running WFW.
You use the regular Windows File Manager to share a directory on a PC running WFW in 386 Enhanced mode. You can let other team members access an entire hard drive, a directory, or (through Print Manager) a printer.
You have three options for setting up security for a shared resource: Read-Only, Full, and Depends on Password. Read-only access
grants people at other workstations the right to view files but not to delete or change them. Read-only access also prevents anyone from creating directories below the shared-resource directory name. Full access lets other people view, edit, and delete files and create or remove directories. With the Depends on Password option, you can give read-only access to some people and full access to others. A person at another computer on the LAN obtains the appropriate level of access by entering a password matching the read-only or full-access password you designate.
Unfortunately, WFW does not maintain a network-wide roster of log-on accounts. Thus, when you use any workstation for the first time, the NOS asks you to register as a new user, even though you've logged on from other machines in the past. The same happens if you mistype your log-on account name.
In addition, you can't prevent someone from adding or removing directories, using more than a designated amount of disk space, modifying file att
ributes, or logging in from multiple workstations. You can't use WFW to force people to use or change passwords, nor does it support a user-groups concept to help distinguish security levels.
The bundled Schedule+ software lets you share your appointment book across the LAN, so you can coordinate meeting times with coworkers. Unlike PowerLan and LANtastic, WFW doesn't recognize power-is-fading signals from a UPS.
Novell's Personal NetWare
Personal NetWare, introduced in fall 1993, is a redesign of Novell's first peer LAN operating system, NetWare Lite. Novell continues to sell NetWare Lite to companies that already use Lite and need to add more PCs. But the company doesn't plan to enhance NetWare Lite with additional functions; instead, it will focus on Personal NetWare. Novell supplies several network adapter drivers with Personal NetWare, and the NOS works with any driver that complies with Novell's ODI standard, just as the client for server-based NetWare does.
As you'd expect, P
ersonal NetWare interoperates well with NetWare 2.2, 3.12, and 4.0. Personal NetWare uses Novell's VLM (Virtual Loadable Module) software technology to manage the loading of the ODI drivers and redirector functions. The latest version of Novell's client kit for the company's server-based NetWare products supports TCP/IP as a substitute for IPX, but Novell hasn't yet updated Personal NetWare to offer TCP/IP connectivity. (You can manually graft TCP/IP into a Personal NetWare environment but only with some difficulty.) Personal NetWare integrates well in a Windows environment and can even install successfully over WFW.
Personal NetWare's components consume 110 KB on a server--16 KB for IPX, 45 KB of server software, and 49 KB of VLM and requester software. On a client-only machine, Personal NetWare uses 65 KB of RAM. Depending on the upper memory that's available in your PC, you can load the 16-KB IPX and 10 KB of the VLM module in upper memory. NWCache is an optional module for boosting server performan
ce, and you can install optional security and SNMP modules.
Personal NetWare supports up to 240 users--fewer than the other peer LAN products. However, Novell suggests you switch to server-based NetWare 3.12 or 4.0 when your LAN grows beyond 25 workstations.
Like WFW, Personal NetWare does not understand UPS signals. Novell makes a Personal NetWare patch available on CompuServe and the Internet (at the ftp site ``ftp.novell.com''); the filename is P10U04.EXE.
Installing and connecting Personal NetWare PCs is fairly simple. However, when I rebooted an active workstation/server PC, simulating a power failure, the other Personal NetWare machines sometimes had trouble reconnecting. No other product had this problem.
Your data is as secure with Personal NetWare as with regular NetWare. For each user, you can enable or disable the account, grant or revoke supervisor (management) privileges, require passwords, set the minimum number of characters and expiration date of the password, and d
elete accounts. For each directory, you can specify default access rights and single out those users who should have nondefault access rights. In a Personal NetWare environment, you can choose to have no security at all by changing the STARTNET.BAT file so that it doesn't load the security module. You save some workstation memory by not loading the security module, but then all workstations have full access to the shared resources of that server.
Performance Technology's PowerLan
The fastest peer-to-peer NOS tested, PowerLan comes with a five-user version of DaVinci eMail for DOS and Windows. (Performance Technology bundled Lotus's cc:Mail product with early versions of PowerLan.) The company also sells remote-control and Epoch groupware calendaring software.
PowerLan's Windows interface uses a plug metaphor to depict shared-resource connections; you drag a plug icon from a drive letter or printer port to a network volume or print queue. Alternatively, network administrators can set up perm
anent drive mappings that everyone on a LAN can use. Even the administrative functions of PowerLan are enabled for drag and drop. You can add a user to a named group by dragging that person's log-on account icon from the nonmember side of a window to the member side.
PowerLan achieves its high performance through well-written software--the NetBIOS implementation is one of the best on the market. Another PowerLan component, a 32-bit, multithreaded dedicated server module called PowerServe, contributed to PowerLan's fast benchmark times. In fact, PowerLan proved to be nearly as fast as NetWare 3.11, beating the other peer LAN products to the finish line and even outpacing Windows NT-Advanced Server 3.5.
PowerLan supports packet drivers, ODI, and NDIS. In addition, it offers monolithic implementations of NetBIOS for most network cards, which cuts the protocol stack's RAM needs and raises its performance, because the monolithic NetBIOS drivers talk directly to particular brands of adapters, making O
DI and NDIS unnecessary. PowerLan easily networks DOS and DOS-and-Windows workstations with other SMB NOSes, such as IBM's LAN Server. PowerLan 3.11 also integrates well into a server-based NetWare environment. With Performance Technology's optional Powerfusion product, you can also easily connect to Unix-based computers.
A PowerLan workstation typically loads the NetBIOS, Redirector, and Server modules, along with the DOS SHARE program. You select other modules at installation time for printer sharing, disk caching, NetWare integration, and workstation remote control.
Without loading PowerLan into high memory, I had 537 KB of conventional RAM free. The SHARE program took 6 KB, the PowerLan NetBIOS took 42 KB, the Redirector took 15 KB, and the optional Server module took 21 KB--a total of 84 KB. (You don't need to load the Server module on a PC that won't act as a server on the LAN.) On a 386 or higher CPU, all of PowerLan can be loaded into high memory; I had 621 KB free for DOS applications i
n this configuration. Also, PowerServe, the dedicated server software, can use all the RAM in a computer to cache disk reads and writes.
I tested the ability of all four NOSes to recognize and respond to signals from a UPS. The PowerLan file server recognized such signals and performed a graceful shutdown before the UPS batteries ran out.
PowerLan's print queue manager lets you see what's in the queue and tells you when the printer is off-line or out of paper. Queue maintenance tasks, such as changing print job priorities and canceling print jobs, are easy. You can connect multiple printers to a single queue and make print jobs go to the printer that becomes available first. PowerLan can even display the target printer on a map of your office, so that you don't have to remember where printer ``HPIVsi'' is located.
PowerLan offers a range of security options. You can assign passwords to shared printers, grant users read/write/create rights for disk drives and directories (but not individua
l files), dole out privileges to users that allow or restrict multiple concurrent server log-ins, and otherwise protect your data. Overall, PowerLan's security features are comparable to those of LANtastic and Personal NetWare, and superior to those of WFW.
The Final Judgment
Where peer access makes sense--in small, cost-conscious groups that need to share disks equally--peer LAN products provide good value. If you want performance, PowerLan is your likely choice. For tight Windows integration on machines that can run in 386 Enhanced mode, Windows for Workgroups is for you. Personal NetWare is especially good at providing peer access in a NetWare server-based environment. And you'd buy LANtastic if you wanted a full-featured peer LAN.
What's the best peer LAN operating system overall? For its combination of features, excellent Windows and NetWare integration, and small RAM footprint on client machines, LANtastic is the best of the four.
The Facts
LANtastic 6.0
P
er node $119
Separately priced five-, 10-, 25-, 50-,
and 100-node kits are also available;
contact Artisoft for details.
Artisoft, Inc.
2202 North Forbes Blvd.
Tucson, AZ 85745
(800) 233-5564
(602) 670-7100
fax: (602) 670-7101
Microsoft Windows for Workgroups 3.11
Per node $219.95
Upgrade from Windows 3.1 $69.95
Microsoft Corp.
1 Microsoft Way
Redmond, WA 98052
(800) 426-9400
(206) 882-8080
fax: (206) 936-7329
Personal NetWare 1.0
Per node $99
Five-node package $395
Novell, Inc.
122 East 1700 South
Provo, UT 84606
(800) 638-9273
(801) 429-7000
fax: (801) 429-5155
PowerLan 3.11
Two-user starter pack $198
Single-user add-on $99
Performance Technology, Inc.
800 Lincoln Center
7800 IH-10 W
San Antonio, TX 78230
(800) 327-8526
(210) 979-2000
fax: (210) 979-2002
Performance Benchmarks
On the same hardware platforms
, and with each product optimized according to the manufacturer's recommendations, the peer LAN operating systems showed markedly different times in tests measuring file I/O speed. Performance Technology's PowerLan, with its 32-bit PowerServe module, was the fastest of the four.
MICROSOFT
WINDOWS FOR PERSONAL
LANTASTIC 6.0 WORKGROUPS 3.11 NETWARE 1.0 POWERLAN 3.11
Seek 1.2 0.3 1.8 0.7
Read 17.3 12.1 19.5 9.5
Write 7.0 6.4 10.7 4.8
Times are in milliseconds. The network consisted of nine mixed-brand 486-based PCs of varying clock speeds, each equipped with an SMC EtherCard Plus network adapter. One machine was dedicated as the file server.
Illustration: LANtastic's toolbars let you single-click on icons to perform network tasks. The included Artisoft E
xchange E-mail is similarly icon-driven.
Illustration: Windows for Workgroups includes a version of the popular Microsoft Mail, which offers one of the best E-mail interfaces available.
Illustration: Personal NetWare makes connecting to NetWare servers or other Personal NetWare PCs easy, because its VLM technology is basically the same one that Novell offers in its client kit for server-based products.
Illustration: PowerLan sports both a toolbar and a PowerLan menu option in File Manager, making it easy to access PowerLan functions in the Windows environment.
Table: FEATURES COMPARISON (This table is not available electronically. Please see December, 1994, issue.)
Barry Nance is a BYTE contributing editor and the author of Using OS/2 Warp 3.0 (Que, 1994) and Client/Server LAN Programming (Que, 1994). You can reach him on the Internet or BIX at
barryn@bix.com
.
Four Peer Operating Systems
