Remote Access Servers
Remote access servers allow users away from the office to dial in to your network, and most allow users on the network to use a modem bank to dial out. This kind of flexibility is becoming important with the shift to mobile and home workers, as we pointed out in our article on RAS in our January 1998 issue. Since the RAS market changes quickly, we thought it time to visit this topic again, comparing a number of units head to head and also checking out the type of RAS units that are available.
The need to find fast, easy to configure remote access methods for a UNIX system has become more important still with the ever-increasing speed of modems and fast dedicated access lines. A couple of years ago most system administrators only had to worry about 28.8kbps modems, which could easily be handled by any of the multiport serial cards on the market. Most users are now working with X terminals on the road, and a slow 28.8 modem just can’t keep up. The development of K56Flex modems, as well as the substantial popularity of ISDN lines for home workers, has meant that multiport serial systems can’t always serve these lines adequately. Add to that the growth of intranetworks and the need to connect wide area networks together even for small companies, and T1 and T3 lines all need supporting, too.
Although the role of the standard multiport serial card is still important to UNIX administrators, a new breed of system has emerged specifically to serve these higher-speed remote access users. These remote access servers allow fast telecommuting with no loss of end-user functionality. Most of the RAS units available today are external devices, added to the network backbone instead of directly to a UNIX server.
To investigate this changing market, we contacted a dozen vendors to request review units of their RAS servers. Ten companies provided their RAS solutions, targeting different sized markets from small companies to the largest organization. We received product from Chase (Nashville, TN), Computone (Alpharetta, GA), Comtrol (St Paul, MN), Digi (Minnetonka, MN), Equinox Systems (Sunrise, FL), MultiTech (Mounds View, MN), Osicom Technologies (Annapolis Junction, MD), Specialix (Campbell , CA), Stallion (Soquel, CA), and Systech (San Diego, CA). We’ll start with a brief description of each product, followed by our testing methodology and results. As you’ll see, each product has its own features and strengths, and offer you several useful alternatives tailored just for your needs.
Chase IOLAN+ Communications Server
Chase’ IOLAN+ Communications Server is available as a rack-mount or separate unit; we tested the latter. The two versions are functionally identical except for the ports: the stand-alone uses DB25 connectors while the rack-mount has RJ45s. The 16-port IOLAN+ (an eight-port version is also available) allows for modems, printers, and any other serial devices to be connected through an Ethernet TCP/IP network.
Physically, the IOLAN+ is a foot long, eight inches wide, and an inch and a half thick block of beige metal. The top of the IOLAN+ has sixteen clearly-numbered DB25 female serial ports. The left side of the case has a detachable power cord and on-off switch, a power LED, and three network connectors (RJ45, BNC, and AUI). Each network connector has an LED next to it to show connectivity. There are no status lights to show port activity, which is unfortunate as these often are useful. Chase includes a loopback detector for the IOLAN+ so each port can be checked, as well as an RJ-45 loopback for the network port. A perfect-bound User and Administrator Guide accompanies the IOLAN+ and is well laid out and written.
Installing the IOLAN+ requires using either a UNIX or Windows NT session. An ARP entry is made first to associate an IP address with the Ethernet physical address of the IOLAN+ (provided on the bottom of the unit). This is followed by a telnet session to the assigned IOLAN+ IP address. The character-based interface of the IOLAN+ allows you to set each port as desired. Stepping through each port and setting speeds and other parameters takes a little while. A quick start guide included with the IOLAN+ means an administrator can set the IOLAN+ up in about ten minutes without ever cracking the User Guide.
When a remote client calls into the IOLAN+, an IP address can be assigned automatically (each port can have a separate IP address, or you can assume the IP of the remote if it’s on the same network). The IOLAN+ supports PPP, SLIP and CSLIP, as well as dedicated telnet and rlogin sessions when directly connected to other systems through a serial cable. RADIUS capabilities are also included. Authentication of remote users is through an optional login and password database.
Although the IOLAN+ is not as easy to set up as some other devices dues to the character-based menu system, this approach does allow for administration from any where (as long as the IOLAN+ manager login is known, of course). It would have been nice to have the option of a GUI for X or Windows.
Computone Intelliserver
The Computone Intelliserver Powerrack was the largest of the serial-port-based RAS units we tested although smaller units are available from the company. Our Intelliserver Powerrack was configured with 16 ports although the unit can be expanded to 64 ports. The Intelliserver Powerrack is one of the few units with a lot of horsepower under the hood (which contributes to both the performance and the price). The system appears to be powered by a MIPS R3000 with 2MB RAM. Each port on the Intelliserver Powerrack can run at speeds up to 921.6kbps.
The Intelliserver Powerrack units is a large dark gray steel box. The front panel has five slide-out panels, the upper three of which were empty on our unit. The fourth panel had 16 RJ45 ports and a single LED to show the card is active. The lowest unit is the network connector and controller, with a BNC and AUI connector (no RJ45) on the front and two status lights. The back panel has a detachable power cord and a small on-off push button. Accompanying the Intelliserver Powerrack is a rack mount kit, a cable with RJ45 on one end and DB25 male on the other for connecting to the server, and a couple of spiral-bound manuals. The well-written manuals include a small hardware guide and a much thicker configuration guide.
Installing the unit requires a bit of room due to the large size and the need to provide adequate ventilation for the rear-mounted fan (which was amazingly quiet). Configuring the Intelliserver Powerrack required a connection to a terminal (or terminal window on a UNIX or Windows system). After powering up, a series of character command lines let you configure the unit one point at a time. A utility included with the system lets each port on the Intelliserver Powerrack look like a UNIX tty port, which makes it easy to configure under SCO OpenServer and UnixWare 7. Expect to spend a bit of time configuring the Intelliserver Powerrack. Setting up the 16 ports using the menu-drive character interface took us about half an hour. The menu-driven interface is good but a little cumbersome to move around.
The Intelliserver Powerrack was unique among our test units in supporting every protocol we could think of wanting. For dial-in sessions the Intelliserver Powerrack supports PPP, SLIP, RIP, RADIUS, and IPCP. The system also supports SNMP for server status updates. The security aspects of the Intelliserver Powerrack are excellent, offering all kinds of flexibility for limiting access and specific hosts that can be reached by each login.
Computone offers a 30-day money back guarantee on their units if you’re not happy with the system’s performance or features, a nice touch. Our only quibble with the Intelliserver Powerrack is the lack of a GUI-driven interface and no RJ-45 Ethernet port. Still, considering the host of features this unit sports, these are almost trivial.
Comtrol Interchange VS 3000
The Comtrol Interchange VS 3000 was the only ISDN-equipped RAS we tested. The Interchange VS 3000 has four ISDN ports, each capable of the usual ISDN 128kbps, or bonding to 512kbps over multiple B channels. The Interchange VS 3000 can be connected to either a Windows NT or Novell NetWare server (no UNIX support planned!). The Interchange VS 3000 allows for automatic switching to a backup server in case the primary crashes. Support is included for Windows NT RAS, as well as NetWare’s Connect and Multiprotocol Routing.
The Interchange VS 3000 is a black box about a foot wide, eight inches deep, and one and a half inches thick. The front panel as a single power LED and a nicely sculpted edge. The back panel as a detachable power cord and on-off switch, a fan (which proved to be quite noisy), four ISDN ports with three status LEDs each (two for the B channels and one D channel light), both AUI and RJ45 network connectors, and a DB9 for connecting to the host Windows or NetWare machines. A rack-mount kit is included as is a spiral-bound configuration guide.
Installing and configuring the Interchange VS 3000 was fast. After connecting the four ISDN ports with the included cables to the wall data jacks, the unit is powered on and the Windows software installed. The Interchange VS 3000 is added through the Network applet under Windows’ Control Panel, then a supplied interface installed. The Interchange VS 3000 interface is clean and easy to work with. It lest you set up all the usual ISDN parameters (SPID and DN) for each port separately, as well as activate DHCP if desired through the Windows RAS page. There is no built-in user authentication scheme, as the Interchange VS 3000 relies on Windows NT to perform these tasks.
Our only real wish for the Interchange VS 3000 is the addition of UNIX support and the ability to override the Windows user access database entries. As it is, there is no way to easily control remote access other than through NT’s User Manager. Oh, and a BNC connector would be nice, too. Picky, aren’t we?
Digi AccelePort Xr
Digi’s RAS offering is the AccelePort Xr system, which is a plug-in ISA multiport system very similar to normal multiport serial cards. Digi’s excellent network-based LANServer RAS server we reviewed in our last look at RAS products has unfortunately been discontinued in favor of these internal boards. The ISA board is connected by an umbilical to either an RJ45 or DB25 breakout box supporting eight lines or a simple octopus cable with four arms terminating in eight DB25 connectors. We were supplied with the latter for testing. Four-port versions of the system are also available.
Installing the AccelePort Xr is exactly the same as a multiport serial card (which this really is). Before installing the card check the system for a four-byte I/O address. Install the ISA card (no PCI version was supplied) and use a backpanel mounted DIP switch to set the I/O address, attach the 78-pin octopus cable, install the drivers from CD-ROM, and run the installation program. Unfortunately the only documentation included with the AccelePort Xr is a fold-out page of hardware installation instructions and a small slip of paper telling you to get new drivers from the Digi Web site. Everything else is on the CD-ROM as on-line manuals. We would have much preferred hard copy.
Drivers for the AccelePort Xr are available for SCO UNIX and UnixWare, NetWare, Windows 95, Windows NT, generic SVR4, and MP-RAS. The drivers on the CD-ROM were current with the versions on the Web site when we checked, but since this is a new product some evolution in drivers is bound to occur. The drivers for both SCO operating systems are installed using a supplied setup script, not SCO’s package managers. The ends of the octopus cable can be plugged into any standard serial device such as a modem (or terminals). It took about half an hour to get the system up and running.
Although Digi markets the AccelePort Xr as a RAS solution, it really is no more than a multiport serial card. Having said that, it’s a fast multiport card. An on-board RISC processor speeds the processing of traffic to the point where each line can support speeds in excess of 900kbps. Although we couldn’t load the system with modems running this fast, we did simulate traffic at 750kbps on all eight lines. The AccelePort Xr does a nice job of offloading the host CPU, but any server is going to take a performance hit with a load like that. With standard K56Flex modems, all eight lines were services cleanly with minimal impact on the host. Surge protection on each line is a bonus. The AccelePort Xr is a classic solution updated to make it current to today’s remote access technology. We really missed a printed manual. The superb LANAServer is missed even more.
Equinox SuperSerial
Equinox is a well-known name in expansion card technology, and their SuperSerial system has been around for several years. Since our last look at the Equinox SuperSerial system in a previous RAS review, the box has changed only a little. The SuperSerial system is ideal for those who want the flexibility to use their own internal modems in different configurations, and allows for excellent expandability.
The SuperSerial system hinges on a plug-in board similar to those used for serial port expansion. Our review unit was shipped with a PCI board, although ISA boards are also available. An umbilical from the backplane of the board leads to a large chassis with its own power supply and sixteen ISA slots on a motherboard. Multiple expansion boxes can be daisy-chained together to allow for even more expansion, up to 128 ports total. Into the ISA ports any internal modem (both analog and high-speed) can be plugged. The SuperSerial case is quite large, measuring about eighteen inches wide, a foot deep, and eight inches high. Behind a hinged front panel are the backplanes of the modems, and a channel under the unit leads wires out the back. Four switches on the front allow individual banks of four modems to be powered up. This system requires its own desk space or rack area. Despite lights on the front for network activity there are no network ports built into the unit. A single spiral-bound manual covers installation and configuration of all the Equinox SuperSerial devices.
Installing the SuperSerial is simple: plug the PCI board into the server, load the configuration software off CD-ROM (drivers for multiple operating systems are included), attach the cable to the subsystem, install modems in the slots, and configure the ports. The whole process took us about half an hour. The subsystem can be installed up to 300 feet from the server, but the supplied cord is only a few feet long. Equinox sent an empty chassis, so we scrounged fourteen V.34 internal and two ISDN internal modems to test the unit. With the swing in modems more to external units these days, finding suitable internal modems may be a problem for some users.
When loaded with traffic from our switch each port of the SuperSerial was able to handle the full throughput without problem. The PCI board has its own processor, offloading the host processor. The configuration for the ports treats the devices like UNIX tty devices, making the process familiar for system administrators. The lack of network connectivity will be a problem for many installations.
Multitech RASFinder 200
The Multitech RASFinder 200 is three modems in a single case the same size and shape as most Multitech modems. More than just a chassis with three 56kbps (K56flex) modems, the RASFinder 200 has network ports on the back and client software to allow sharing of the modem system over the network. Management of the RASFinder 200 is through Windows-based software from either Windows 95 or Windows NT machines. We tried the software under Wabi on a SCO OpenServer system without much luck, although we didn’t try excessively hard to get the software working.
The front panel of the RASFinder 200 has separate transmit, receive, carrier detect and ready lights for each of the three internal modems. A separate bank of lights indicates network traffic. Finally, two LEDs show unit power and a failure condition. The back of the RASFinder 200 has three telephone jacks (three shortish cords are included), both RJ45 and BNC connectors for the network, a power socket and on-off switch, and a second RJ45 labeled command for connecting directly to a host computer. The power supply is the usual wall-wart type. A short installation manual is provided with a User Guide supplied in Acrobat format on floppy.
Setup of the RASFinder 200 is straightforward. The shipping box contains everything you need except a network cable. The network connection can be through either the BNC or RJ45 sockets and the system works with both TCP/IP and IPX/SPX. We had to use an extension male-to-female cable to get to our serial breakout box, as will most administrators who do not stack their modems within a few inches of the server. The configuration software was loaded on a Windows NT server in a few minutes off the two diskettes.
One major inconvenience of the RASFinder 200 management software is that it expects to find the connection to the modems on COM1 through COM4. For those using many serial ports through a breakout box, this can be annoying. In our case we had to juggle several peripherals to allow the RASFinder 200 to exist on COM4. The management software lets you input the IP addresses for each modem on the RASFinder 200 as well as remote addresses. A single window then lets you set parameters for each modem such as whether to accept incoming calls, connection speed limits, and whether a direct
connection exists. The management software can be run remotely, if easier for the administrator. A flash BIOS in the RASFinder 200 allows firmware upgrades, if necessary, in the future.
Every user who is going to dial in to the RASFinder 200 has to have an entry in the server’s remote user database. Each name has to be added separately (there is no import facility for pulling lists of users from the NT User Manager). A password is assigned to each user’s access. Call backs are supported either in security mode (where the system administrator specifies the call back number for each user) or the user can enter their call-back number themselves before the RASFinder 200 terminates the session. Any client can connect to the RASFinder 200 as long as they support PPP or SLIP. Authentication is through either PAP or CHAP.
A couple of wish-list items arose as we tested the RASFinder 200. First, our lament about COM ports deserves fixing. We also would like the option to have fax modems installed on one or more of the ports. This would enhance the use of the RASFinder 200 for small businesses which could use one line for faxes and others for dial-in. Other than that, the RASFinder 200 is a fine product that is ideal for the smaller companies that don’t need large numbers of ports. The small size makes the RASFinder 200 easy to tuck into an installation.
Osicom IQX-200
The Osicom IQX-200 was a bit of an enigma when it arrived for testing. It arrived in a large box with a single page of setup instructions. No manual, no product spec sheets, nothing. Whether this is usual is unlikely. Chances are in the rush to get a review unit off to us something got lost in the process. The IQX-200 was also unusual for another reason: it’s not a typical RAS unit. It can be configured with standard ports (from 8 to 168!) although we didn’t have those ports available for testing.
The size of the IQX-200 is about that of a small PC tower. The beige box has a nicely curved from panel with a row of status lights embedded near the top. The back panel looks like the rear of a tower computer, too, with a line of backpanels showing. There were three sets of T1 connector cards, a standard RJ-25 Ethernet card, a slot with an 8MB flashRAM PC Card, and a single DB9 connector. A power cord and on-off switch completed the system.
Installing the IQX-200 consisted of using supplied cables to connect the three T1 adapters on the back panel to the PBX, the Ethernet card to the network, and the DB9 connector to a terminal. Powering up the system went through a bunch of diagnostics then displayed a login prompt. The system then prompts for all the configuration information, although references to the manual left us lost. Even so, we couldn’t really test the IQX-200 since we didn’t have three T1 lines available. To solve this problem we rolled the unit out to a local University computer science lab and plugged in there. The three T1 lines all came up perfectly (after a little configuration voodoo by the communications expert there) and the IQX-200 allows full communications in and out of the LAN using those circuits.
The IQX-200 can be configured with a host of other cards including ISDN and synchronous modems, and FDDI cards (both single and dual). Obviously, the IQX-200 is not a low-cost RAS unit but a full-features stand-alone switch which can be configured to the user’s requirements. Since we were unable to compare the IQX-200 to anything in our test network, we didn’t measure its performance. Suffice it to say that if you’re looking for a unit that can handle any of the fast telephone setups (ISDN or T1) this is a unit that’s capable.
Specialix Jetstream 8500
Specialix’ Jetstream 8500 is a 16-port RAS unit available in several configurations. We tested a 16-port version, each port capable of 230kbps.
The Jetstream 8500 is a light grey color rack-sized unit (rack mount kit included) about one and a half inches thick. The back panel of the Jetstream 8500 has a detachable power cord next to an on-off switch, a DB25 connector for a configuration console, and both RJ45 and AUI Ethernet connectors. The front panel has 16 RJ45 ports and two LEDs. A set of rubber feet are included for stacking purposes. A thin spiral-bound installation guide accompanies the CD-ROM that includes documentation and device drivers.
Installing the unit was simple. Configuring can be done either from a terminal or through a new browser interface. A terminal or serial cable to a window is attached to the back connector and set to emulate either a VT100, Wyse 60, or ANSI terminal. A login prompt leads to the menu-driven interface. After entering the IP address, authentication method, and port information, the unit is ready to go.
A more attractive method to configure the Jetstream 8500 is to use a browser once the Jetstream 8500’s IP address has been set. The browser interface is clean and easy to work with. Under SCO UnixWare, the ports on the Jetstream 8500 can be configured as tty devices directly attached to the system. A supplemental guide leads you through all the steps for setting up the Jetstream 8500 from UnixWare.
The ability to configure the Jetstream 8500 through a browser and set up all the ports as tty devices makes this unit attractive to UNIX users. With support for PAP, CHAP, and RADIUS, the Jetstream 8500 includes all the authentication protocols you need. Up to 32 users and passwords can be added to the unit database. Callbacks are supported. With a flash BIOS, the Jetstream 8500 is a talented unit. Oh, we’d like to see a BNC port.
Stallion EasyServer II
The Stallion EasyServer II is a smallish eight-port server (16 ports are also available) unique for including HTTP pages in its BIOS for configuration, as well as the possibility of loading your own Web pages for faster retrieval by remote users. The EasyServer II supports SNMP for management functionality, and by using HTTP for all functions allows administration from any connected device with a browser.
Physically the EasyServer II is the smallest RAS unit we tested. It is about eight inches wide, six inched deep, and an inch and a half high. The gray box has a curved roof with ventilation holes drilled in the top. The front of the unit has four status lights, while the back sports a detachable power cord (no on-off switch), eight RJ45 connectors for modems or other devices, and both BNC and RJ45 connectors. No host connector is provided as the first port is used for configuration. The EasyServer II uses a flash BIOS for upgradability.
Configuring the EasyServer II requires connecting a terminal to the first port although this can be avoided if DHCP, BOOTP, or RARP is active on the network. After connecting, a browser is used to load the EasyServer II’s home page. By default all prots are configured to 9600 baud, so these will need modifying for modems. Stallion provides kits of RJ45 to DB25 cables for device connection. Configuring the device through a browser is an interesting and novel experience, but doesn’t really bear any advantage over other schemes. The EasyServer II allows you to set up a user access list with passwords, and supports PPP and SLIP. PAP, CHAP and RADIUS are supported for authentication. Configuring the EasyServer II took about ten minutes.
Working with the EasyServer II proved simple. It served both outgoing and incoming calls well and has some flexibility for dial-on-demand service. The ability to store Web pages may be important for some users. Our only real complaint is that it’s impossible to rack mount this server.
Systech RCS/4000
Systech’s RCS/4000 is a neat-looking alternative to a rack unit. Sporting 16 ports and some flexibility in its setup, the RCS/4000 offers a smaller organization some interesting alternatives. For example, the unit can be wall-mounted with ease, simplifying and tidying cable layouts.
The Systech unit looks different from the others in this review. The small black case is extremely light and rounded, totally unable to be rack-mounted, but attractive as a stand-alone unit. The front panel has 16 RJ45 ports and a power light. The back panel has both BNC and RJ45 connectors for the Ethernet network, a DB25 serial port for connecting to a host computer, and – the only tested unit to feature one – a parallel port. The back also has a socket that attaches to a larger-than-usual power supply. There’s no on-off switch with the unit. A thick spiral-bound installation and configuration guide accompanies the unit.
Configuring the RCS/4000 was simple: connect the cables, plug the unit in, and attach a terminal. The IP address for the unit is set from the terminal or through a dynamic method (DHCP, BOOTP or ARP). After logging in to the unit character commands set the IP address and netmask. Configuring each port to different settings than the default 9600/8/1 parameters is a bit of a pain as each parameter is issued one at a time. The setup process for all 16 ports took us about 30 minutes. The system can be configured with a GUI routine from a Windows 95 or NT station, which is much neater and faster. The parallel port on the back of the unit supports UNIX lpd routines, which is a handy feature. The DB25 connector on the back can be configured as a LAN-to-WAN router or synchronous modem (such as ISDN) once the RCS/4000’s settings are completed. The unit supports SNMP.
The user guide includes a lot of sample configurations for clients which will help novice system administrators configure the system properly. There is no provision for user authentication in the unit, but the controlling server (Windows or UNIX) can perform these tasks. The RCS/4000 was one of the more interesting units in our test, and one that we would think ideal for the small company looking for maximum flexibility at a reasonable price.
How we tested
Because there was a number of different testing environments required, we couldn’t subject each RAS unit in this review to the same barrage of tests. For example, the Comtrol Interchange VS 3000 is ISDN-only, so a comparison to servers using standard asynch modems is meaningless. Still, we managed to test all the units thoroughly. Only the Osicom RAS server worked with our 100Mbps network, which was unfortunate as many of the other units would have benefited from the higher network throughput.
Each of the units that offer serial ports that can be configured for multiple uses was installed on either a Windows NT 4 Server or SCO OpenServer server (both machines were dual-266MHz Pentium II ALR Revolution 2XLs with 128MB RAM). A set of 25 Windows and UNIX clients on a dual 10Mbps and 100Mbpd network were used for dial-out and dial-in testing (seventeen of the clients had Hayes 28.8kbps modems and eight had Multitech K56Flex modems on them). An in-house PBX handled the call routing to avoid lag over standard telephone lines. The PBX allowed for four ISDN lines, which were used for testing the Comtrol Interchange VS 3000. The Multitech RASFinder system has three modems built in, so those were used directly.
Each RAS unit was properly installed and allowed to function in the network for three days of dial-in and dial-out use to out-going lines before switching to the internal-only PBX. This allowed the units to break in a little, as well as give the testers a feel for each unit'’ responses and configuration utilities. To test each system with varying loads we used in-house clients to dial through the RAS to external numbers (looped back to modems attached to other clients). To test dial-in each client called through the PBX to the RAS and attempted to attach to both servers and other clients. Loading was done in increments of four (four, eight, twelve, and sixteen active modems) where supported. To load the connections once established, a set of scripts simulated heavy Web server usage and file transfers using FTP. Throughput of the devices was measured both between modem and RAS and RAS and network using a Fluke datascope. Loads were sustained for two hours and results averaged. The test was then repeated a second time.
To test the ISDN ports on the Comtrol unit we used both ISDN and analog connections through ISDN lines. The results are not comparable to the asynch-only ports. Since most RAS units supported port speeds faster than an asynch modem can sustain, we also used direct connection between units to ensure maximum rated port speeds could be reached. However, since most RAS units are used with asynch modems we didn’t dwell on these results.
Testing
The Multitech RASFinder 200 was the only RAS unit we tested that had asynchronous modems built-in, so it can’t be directly compared to other servers that allow flexibility of modem complement and port usage. The Multitech unit performed well over our 10Mbps Ethernet network but couldn’t handle 100Mbps. The throughput on the three modems was slightly above average when loaded with three clients incoming using 56k and 28.8 modems. Performance measured marginally better through the BNC network connection than the RJ45. We had to test the Comtrol Interchange VS 3000 separately too, as it was the only RAS with ISDN built in. We did test both ISDN and analog-over-ISDN capabilities and the unit performed perfectly. As noted in the comments earlier, the Osicom unit wasn’t tested on our normal test network due to its configuration.
Testing the other port-based RAS units revealed that there really isn’t much difference between units when using a set of standard asynch modems. Although a little variation in average throughput was measured with each server, there’s not enough of a performance difference to dictate a purchasing decision. In testing with both 28.8 and 56k modems all the units responded well. We didn’t have a single failure in the three weeks of testing, which bodes well for the market as a whole. We did find different likes and dislikes among the units, mostly based on their ease of configuration (as noted in the individual reviews) and their connectivity to our test networks.
A few units stood out for several reasons. First, the Computone Intelliserver had the fastest port capabilities in the test, allowing 921.6kbps on each port. To test the ability of the system to handle high loads we strung eight cables in a loopback arrangement and found that each port could be pushed very close to the maximum speed. Our datascope couldn’t produce a final number, but we’ll take Computone’s word for their blazing port speed. We did especially like those units that could be configured through browsers, a trend we hope will soon replace terminal connections for all but setting the IP address. None of the units generated appreciable heat or noise, and all should fit well into both small server installations and dedicated IS rooms.
Summary
As mentioned in the testing portion above, all the units showed excellent robustness. Any of the units we reviewed will serve you well and run at about the same throughput, so you should choose your RAS more on the network connectivity, port complement, and price than on speeds.
For a small company requiring just a few ports, there is no inexpensive solution. Perhaps the best bet for one to three ports is the Multitech unit, as it has modems built in. If you have a stack of modems already sitting on the shelf, the Digi, Systech, Stallion, or Specialix units are all competitively priced. We particularly liked the Systech unit for additional features, but it can’t grow as easily as the others. Still, for up to 16 ports, Systech gets our Top of the World award.
Need more than 16 ports or better than K56Flex? You need to spend more bucks and go for one of the expandable solutions. Although expensive, the Computone unit is a Top of the World winner in this category for its sheer flexibility and power. Is there a single clear winner in the review group? No. Use your own criteria, not ours.
Copyright © 1995- Tim Parker Consultant Incorporated. All Rights Reserved.