In keeping with our view of ISDN modems as commodities, we reduced the weight given to performance to 50 percent. Because ISDN modems have a reputation for being difficult to install and set up, we based 30 percent of the overall score on each modem's u
sability rating. We allocated 20 percent of the overall score to the modem's feature set.
The leader in the ISDN category was the 3Com Impact IQ. Although its performance was a few percent shy of the Arescom Flash 200, the performance leader, the Impact IQ more than compensated for it in other categories. The Impact IQ tied the U.S. Robotics Courier I-Modem w/V.Everything for top score in features. But the Impact IQ's high usability rating put it over the top as the clear winner in its category.
Although it delivered performance, usability, and features, the Impact IQ tied as the most expensive of the ISDN modems -- $399. If you're willing to invest some time and effort during installation and setup, however, the $195 Flash 200 can cut your equipment costs in half without compromising on performance.
Double or Nothing
In the 56-Kbps arena, we did see quantifiable performance differences between the two varieties of 56-Kbps technologies as well as among the modems using each technolo
gy. Because performance varied -- and fell short of advertised speeds -- we put a 70 percent emphasis on data throughput under both clean and impaired conditions. Usability, still an important issue when adding or upgrading modems, accounts for 20 percent of the overall score. Features, mainly a function of which chip set the manufacturer uses, have a 10 percent weighting.
Because the two 56-Kbps encoding technologies, X2 and K56flex, are incompatible, we chose a Best Overall from each camp. Even so, the top four overall winners were simply internal and external versions of the same two modems.
The K56flex winners were the external and internal versions of the same modem: the Zoom Telephonics 2849-PC. The Zoom external version produced our top performance score among all modems, regardless of technology. Performance for the internal version lagged about 10 percent behind its external twin, putting it fourth overall. Solid usability and feature scores helped ensure both modems a first-row finish.
If you're looking for an X2 modem, we suggest either the internal or external version of the U.S. Robotics Courier V.Everything V.34. Both Couriers turned in top performance scores among X2 modems, with the faster Courier external modem placing about 6 percent behind the K56flex speed champ. The Couriers' top feature scores helped balance out their relatively low usability ratings.
Adolescent ADSL
Representing the new kids on the block, ADSL modems turned out to be too slippery to pin down. Standards, test requirements, and feature sets for all the variations of ADSL are still under development. Although a number of ADSL modems were available for testing, it's not fair to say that they're in mass production. Because ADSL technology is too immature, we declined to name a Best Overall winner in this category. Instead, we present some test results of what we believe is a real-world scenario.
Best Overall: High-Speed Modems
