This attribute specifies whether this VoiceRoute differentiates
between modemFax traffic and speech. If modemFaxSpeechDiscrim
is on and a false 2100 Hz tone is detected, any Svs using this route
reverts to speech mode when speech is detected.
modemFaxSpeechDiscrim is not used on DS1V, E1V, 1pDS1V,
1pE1V and J2MV cards.