Eicon DIVA Pro 2.0 Hits All The Righ t ISDN Notes Despite the high performance, the main CPU stays relatively unburdened, thanks to the DIVA Pro's onboard digital signal processor and memory. Our testing was completed on a 50-MHz 80486 computer (a dinosaur by many standards). Nevertheless, kernel-processor utilization stayed at a cool 5 percent to 10 percent, while a connection was maintained in the background. File transfers without compression consumed 15 percent to 20 percent of the CPU. When compression was added, utilization hovered around 45 percent (which is still relatively light given the anemic computer that hosted the card). DIVA Pro 2.0 uses Windows95's layered communications architecture. Eicon provides some hardware-specific drivers and a WAN miniport driver for the DIVA, and Microsoft provides the rest, including PPP and Multilink PPP channel bundling. This integration is good news for system stability. Ou r only complaint with this approach is Microsoft's slow embrace of ISDN services; its ISDN Accelerator Pack 1.1 supports only a static Multilink configuration. The net effect of Microsoft's weak Multilink support is that you have to pay more attention to the bandwidth you're using. If you want to place a phone call over the POTS lines while a two-channel data session is in progress, you must suspend a channel manually and replace it when finished talking. Likewise, calls received during a dual-channel session will receive a busy signal. Other devices on the market will free a B channel so that the line can ring. The Multilink Standard does not specify the conditions under which channels are added or removed, so technically, Microsoft is complying with the specification. Yet the use of the second B channel should be based on traffic (added or removed transparently). Why should you have to know how much bandwidth your application needs? With this current configuration, ISDN-usage fees are likely to be hig her than with smarter, traffic-based implementations. DIVA Pro 2.0 passed all of our operational tests fl awlessly. We tested the external POTS box support by assigning a different number to each analog jack. The correct device rang when its assigned number was called, even when one channel was in use for an ISDN data call. Analog modem calls consistently negotiated at the card's highest supported speed of 14.4 Kbps. We placed outgoing fax, data and voice calls over the POTS lines without error. Warm-Up Notes To isolate any setup problems, Eicon provides DiTrace, a text-based DOS application that monitors and displays the call-progress dialog and PPP messages with the switch. Using this tool, the most common ISDN setup problems, including physical cabling and SPID misconfiguration, are relatively easy to diagnose--something we were able to verify during our testing. If you follow the installation instructions carefully, you probably will not need to use it. DIVA Pro 2.0 supports Windows Plug-and-Play, and there are no jumpers to set. You put the card in a slot, boot up and begin answering questions. First, you're prompted for switch type, SPIDs and directory numbers. Then you apply those directory numbers to the logical modems, and assign the fax board, analog modem and/or the ISDN modem to pick up for a given number being called. If using the POTS jack, you assign numbers to each port. Finally, reboot the system, and you're ready to configure Windows Dial-Up Networking. Configuring two B channel calls, frequently the most difficult aspect of software setup, is quite simple. What a relief. David Willis can be reached at dwillis@nwc.com.

Symantec's Gulliver's Travels by Kevin D. Cooke Updated March 7, 1997