A phone which is connected to the network through a Sprint Airave can not receive DTMF (touchtone) tones. Turn the Airave off and connect the same phone through the regular cell tower, and the DTMF tone is passed, no problem. Is there a way to force the Airave to pass DTMF tones? If not, any work around? Out of curiousity, why would an Airave be designed to strip/suppress DTMF tones?