Conexant D850 56K V.9x DFVc Modem for my Dell E521
Though DFVc stands Data, Fax, and Voice compatible, this modem is not truly Voice compatiable
Both these AT commands indicate it is not a voice modem.
AT+FCLASS=? - 0,1
AT#CLS=? - COMMAND NOT SUPPORTED
Dell Quality contol strikes again.