V.92 modems will help dial-up users

With the latest standard for 56K modems expected to be finalized by the International Telecommunication Union this fall, enterprise network administrators should consider upgrading to the standard, called V.92, to deliver a more "broadband-like" experience to dial-up users with analog modems.

The V.92 standard has three core advances: significantly faster upstream speed, quick-connect and modem-on-hold features. The first improvement may well unleash applications that were previously considered unfeasible; the latter doubtless will be seen as a productivity boost for at-home workers and travelers. Overall, the new specification can foster newfound capabilities as businesses transition into the era of unified voice/data networking.

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The redesign of the upstream modulation to accommodate the pulse code modulation (PCM) codec, which converts analog signals to digital, represents the biggest change and required the greatest technological effort. While the current standard, V.90, offers a maximum upstream data rate of 33.6K bit/sec, V.92 uses PCM, with a maximum specified rate of 48K bit/sec.

For large companies, the most notable benefit will be faster uploading of files, including e-mails and graphics, and enough bandwidth to make dial-up voice-over-IP, low-rate videoconferencing and multiplayer online games more feasible.

Faster throughput also translates into shorter connect times. Furthermore, maximizing the use of existing network infrastructure by enabling new upstream applications can potentially change network usage while increasing offsite productivity. Network administrators will need to ensure that headend equipment designed for V.90 is optimized to handle the enhanced upstream performance of V.92.

Current modems assume that each connection is from a new location. In reality, the same phone lines connect repeatedly. Quick connect shortens a modem's time to learn a phone line's characteristics by reusing some information previously learned.

With V.92, the training handshake process has been designed to be intelligent and flexible. As is the case with PCM upstream, there is a cost advantage to this feature, as shorter connect times also translate into operational savings.

The modem-on-hold feature lets modems gracefully break a connection and stand by while another call is taken. Clients can accept incoming calls without crashing the connection, so users can access the Internet or corporate network without missing telephone calls, or pause browsing to make a call (with less need for second lines at home).

Used in conjunction with quick connect, the modem-on-hold feature can make resumption of the data call quicker and more seamless. Furthermore, by enabling servers to pause rather than drop long-idled users, modem-on-hold can greatly enhance quality of service and potentially increase worker productivity.

While the feature poses no threat of disruption to applications users may be running, network administrators may nevertheless want to be proactive in determining the implications of modem-on-hold for their networks.

The decision to upgrade a network to the V.92 standard will depend on a company's specific needs and the vendor-specific equipment in place. Upgrading to V.92 represents no increase in the processing requirement. Typically, it should involve just a flash upgrade or a software upgrade. If current equipment was able to upgrade to V.90, in most cases it should accommodate the V.92 leap. Dial-up service providers that provide access to the Internet or through VPNs to corporate networks are expected to quickly upgrade their systems to support V.92.

A company's digital headend modem should be the first to be upgraded to V.92, with client analog modems upgraded as needed. As new PCs and laptops are released with V.92, the client side will upgrade through turnover. Also, clients who have software modems or flash upgradable modems can download upgrades at low cost.

Perhaps most important, V.92 promises happier dial-in users, for which any network administrator will be most grateful.

Ambion is product marketing manager for the Desktop and Mobile Product Line, Motorola Software Products Division. He can be reached at jason.ambion@motorola.com.

International Telecommunication Union