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.