StarTech.com SV441DUSBI instruction manual Connecting a Modem, Modem Connection

Instruction Manual

with other devices. If you wish to use this feature through a PBX system, it may require some experimentation and additional support from your telecom services provider, and is not supported by StarTech.com.

Connecting a Modem

Modem Connection

The SV441DUSBI will work with virtually any Hayes-compatible modem that recognizes the standard AT command set. Some modem manu- facturers offer “enterprise” grade modem products (at a premium price) that include technology to improve the stability of connections; whether this type of product would be beneficial to your application depends on whether you consider the modem connection to be mission-critical, the quality of your telecom infrastructure, and your budget for implementing this solution. The model of modem attached is essentially transparent to the SV441DUSBI.

It is important to note that modems that offer “56K” (or 57,000 bps) con- nections often achieve connection speeds that are far lower than their maximum capabilities. Given the limitations of telecom infrastructure (many locations have yet to implement fully digital switching technol- ogy, and still rely on older analog technology for some segments), the maximum “upstream” transfer rate is limited to a maximum of 33,600 bps between two modems; the “downstream” rate is often within a similar range for a typical connection. Therefore, speeds below 57,000 bps do not indicate a problem with the modem or the SV441DUSBI, but simply reflect the line conditions at the time the connection is made. The Serial port can be used for serial port configuration when the modem is con- nected. It requires the use of a null modem serial cable.

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