In terms of performance, we found that little separates most of the V.90 cards. We were surprised that, even for beta code on the modem, the throughput numbers were fairly high.

For the most part, the performance increase from V.34 to V.90 ranged from 55 percent to 65 percent. With an average V.90 connect speed of 46,259 bps and a V.34 connect speed of 27,909 bps across all the modems, as tested against Ascend Communciations' Ascend MAX, the V.90 connections on average performed 60 percent faster. The Ascend MAX is a remote-access server that supports both V.90 and KFlex. We used the MAX to simulate an ISP connection.

Manage Thy Modem Many V.90 modems require no special handling, but if you're offering modem support for users or relying on vendor support, you'll have to deal with some user questions and problem resolution. Many of the common problems, such as firmware upgrades and hardware integration, have been handled by the vendors. Internal modems may be problematic in PCs that have many peripherals installed. External modems attached to an existing COM port are a simpler, though more expensive, option.

As recently as a few months ago, many modem upgrades required users to gather information about their modems, such as current versions, COM port and IRQ settings. Once all the information had been gathered, users had to boot to DOS and run a command-line utility, entering information when prompted. Often, even when this was all done correctly, the upgrade would fail, ruining the modem.

These days, the upgrade process is typically much easier and less prone to errors. During our V.90 modem tests, we found that every vendor had an easy-to-use upgrade application that would locate modems, determine the current revision and upgrade the modem automatically. Most notably, if the modem revision were current, the upgrade process would halt.

The exception to this easy-to-upgrade rule is found with so-called "soft modems," or modems that do some of the processing on the main CPU, where the process may be a bit more complex and can leave a user's PC unstable. With soft modems, such as the Digicom Systems DI5610, there's an extra step. Users must manually delete configuration files from the \windows\inf directory that holds information files about hardware and software drivers. Although this process is well documented, it is error-prone, and deleting the wrong file can adversely affect Windows' behavior.

With ISA Plug-n-Play (PNP) hardware and PCI support for desktop users, many of the thorny hardware issues have fallen by the wayside for common hardware configurations. But whose configuration is common anymore? Between PCI modems and ISA PNP, PCI offers fewer problems with hardware configuration than does ISA, for little or no increase in costs. While it's true that PNP eases much of the pain associated with hardware installation for ISA devices, newer PCs running multimedia hardware and software gobble up resources, which leads to conflicts. In fact, we ran into this problem during our V.90 modem tests.

Modem Miscellany External modems are used in the network for out-of-band management on routers, switches and other infrastructure. However, very few modems (the 3Com-US Robotics Courier V.Everything is an exception) offer communications settings via external DIP switches and support for synchronous data communications. The DIPs let you easily configure the modem and move it from one device to another without connecting to a terminal. In our labs, we use a Courier V.Everything specifically for that purpose. Other external modems will work just as well, but if you need to change the auto-answer or flow-control setting, you'll have to connect it to a PC first.

Finally, with PC Cards, connecting the phone line to the wall jack poses some interesting problems. Frequent travelers are usually cramped for space and don't want to deal with the hassle of numerous connectors. Many solutions to this problem involve a vendor-specific cable connector that plugs into the PC Card and has a standard RJ-11 connector for the wall jack. While this arrangement is useful, it doesn't leave much room for extending the phone line more than a few feet. Dongles are also popular connectors, and you can carry as much phone line as necessary. X-Jacks bundle the dongle concept into the card in a neat package. However, they can get in the way of other PC Cards, such as a NIC with an RJ-45 dongle. Unique to this market is Xircom's internal RJ-11 connector on its RealPort Family of cards. No more dongles to lose and no X-Jack to get in the way, but you pay for that convenience: You lose access to the upper PC Card slot.

Send your comments on this article to Mike Fratto at mfratto@nwc.com.