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  It's V.90 Modems for the Speed You Need March 8, 1999
So many modems are available with so many variables that it's difficult to give a blanket recommendation of any specific model. In many cases, the decision will boil down to price--but the more expensive modems have features that justify the extra cost. For users who work from home, you must decide whether to go with internal or external modems. To answer that question, ask yourself if you want your users opening up their computers to install modem cards. Although internal modems mean there's one fewer piece of equipment to clutter the user's workspace, internal hardware installation is often tricky and mistakes can leave quite a mess. For frequent travelers, figure out if your costs will be affected by advanced services, such as ISDN, international support and cellular capabilities. Know Thy Modem Unfortunately, a V.90-capable modem won't guarantee better performance than your current modem delivers. Various outside factors--such as line quality, vendor implementations and ISP equipment--may impair performance. Even with a ratified standard, DSP (Digital Signal Processor) manufacturers, including Lucent, Rockwell and 3Com Corp., are making adjustments to their modem firmware and they will continue to do so for some time. Luckily, most manufacturers offer free firmware upgrades, so you won't have to pay for your vendor's future adjustments. Many ISPs are cautious about upgrading firmware on critical servers, such as modem pools and remote-access servers. The ISPs walk a fine line between ensuring a high degree of reliability for their users and keeping abreast of leading technology. Expect to see slow V.90 rollouts, because "buggy" V.90 code may adversely affect V.34 users. Many ISPs have been beta testing V.90 and 56-Kbps technologies in limited areas. Go directly to your ISP to find out what's being used. Any V.90 modem will first try negotiating V.90. If unsuccessful, the modem will fall back to V.34. In addition, nearly all V.90 modems implement one of the other 56-Kbps technologies--K56Flex or x2. TDK Systems' Cyber Express 5600 and General DataComm's Quester III are exceptions--both support only the V.90 and V.34 standards. When multiple 56-Kbps technologies are supported, vendors include all the protocols in a negotiation chain--the modem tries each protocol in turn, and if the protocol fails to negotiate, it moves on to the next protocol. Usually, K56Flex or x2 negotiation is attempted first, followed by V.90, then V.34. There are two exceptions to this rule of thumb: Xircom's CreditCard CM56G and Modem 33 fail to autonegotiate multiple 56-Kbps technologies. Bear in mind that this process adds a significant amount of time to the modem negotiation sequence. In some cases during Network Computing's recent modem tests (see "V.90 Modems Burn Up the Wires With Standards-Based 56-Kbps Access," at www.networkcomputing.com/921/921r2.html), we saw negotiation times last well past one minute, but the wait may be worth the performance boost provided at 56 Kbps.
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