3Com 3C882 manual COM port, Compression

Models: 3C882

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GLOSSARY 2

COM port

The communications port (also referred to as a serial port). The 3C882 ISDN modem communications port allows a maximum baud rate of 230.4 Kbps. Note that most computer COM ports only allow a maximum of 115.2 Kbps. However, accelerator cards can be purchased to increase the computer’s COM port rate to 230.4 Kbps.

Compression

Compression is a method of reducing the size of data packets without losing any information. The 3C882 ISDN modem automatically compresses data for PPP calls to improve data transfer times using the Staccompression method. The following check modes are negotiable— None, One Byte Sequence Number, and Extended. Extended is the preferred choice. The degree of compression depends on the type of file being transferred. For example, a text-only file compresses better than a file with graphics.

D channel

The signaling channel on an ISDN line used to carry messages between the 3C882 ISDN modem and the public switch.

DBA

Dynamic bandwidth allocation. DBA is a method of reallocating bandwidth (such as a B channel) automatically. DBA allows you to place or receive a voice call while a Multilink PPP call is active.

Default

Value set at the factory.

Firmware

Firmware is the code which resides in the 3C882 ISDN modem and controls its behavior. It differs from software in the form of programs that run on your computer.

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3Com 3C882 manual COM port, Compression