DSP Technology to Make Life Simpler for ISPs

A Cool Solution
According to Patton chief engineer Bill Clery, the Patton Model 2800 accomplishes this by clever use of DSP (Digital Signal Processor) technology, which allows one V.34+ digital modem (33.6 kbps) or two ISDN terminal adapters to fit on a single, programmable chip that combines T1/E1 framing, signalling and physicall interface functions into one IC. What is the main advantage of being able to fit the functionality of one or two modems onto a single chip? Besides the obvious savings of shelf upon shelf of real estate, Clery also predicts a significant increase in reliability. "It all comes down to power consumption," says Clery, "As power consumption is reduced through decreased external bus access, heat dissipation becomes less of a problem. So you can fit the modems tightly together. And since there is a significant connection between heat dissipation and reliability, these cooler running modems are also more reliable."

Upgrades in a Flash
But there is more to the Model 2800 than space savings and reduced down time. The Model 2800 keeps software in a central storage location and downloads instructions (in large data blocks) to the DSP chips as needed. As Clery puts it, "WHat this means to the end user is that upgrades to all thirty modems can be implemented with simple FTP download to the box." These upgrades can even include upgrades in DSP functionality (adding ISDN or 56 kbps support, for example), since all the software telling the DSPs what protocols to run is stored in the host processor's Flash memory bank. "With these kinds of digital technologies," says Clery, "traditional limitations to modem functionality no longer exist: The same chip tyhat performed the functions of a V.34+ digital modem can be Flash programmed to perform the functions of an ISDN terminal adapter."

Practical Benfits
While the migration of modem technology from analog to digital has been a forgone conclusion for many years, the Patton Model 2800 Programmable Access Router provides a clear example of the practical benefits of this migration: tremendous space savings, increased reliablity, and a previously unattainable flexibility in modem functionality. Best of all for the small ISP, these benefits come at a very reasonable cost.