Fax Class 1 commands
+FAE=n Data/Fax Auto Answer
+FCLASS=n Service Class
+FRH=n Receive data with HDLC framing
+FRM=n Receive data
+FRS=n Receive silence
+FTH=n Transmit data with HDLC framing
+FTM=n Transmit data
+FTS=n Stop transmission and wait
Fax Class 2 commands
+FCLASS=n Services class.