The system includes a driver for modems that conform to TIA/EIA-592 draft SP-2388-A of August 30, 1991. Unfortunately, because this was only a draft, there are many modems that claim to conform to this document, but which diverge in sometimes subtle ways.

The Class 2 driver has been extensively tested with a wide variety of Class 2 modems. The software attempts to work around many incompatibilities and mistakes in modem firmware. A common problem that requires special attention is that some modems are incapable of accepting an AT+FDIS command to set the session parameters between the time a call is placed and a page is transmitted. Modems with this sort of problem may ignore the AT+FDIS command which causes incorrect session parameters being used to interpret the page data (often resulting in ``squished pages''), or abort the session, returning a +FHNG: status message to the host. If you encounter this problem use the Class2DDISCmd configuration parameter to enable workaround support in the fax server; e.g.

HylaFAX table of contents. Last updated $Date: 2002/05/02 22:02:56 $.