Can Called Party send DTMF

Hello
I am using a SIP service providers and xfer to an IVR (Both the called parties (xfer lines) are USA lanlines , using rfc2833.
the called party not able to send DTMF, any way to resolve this?
Regards
devafree
I am using a SIP service providers and xfer to an IVR (Both the called parties (xfer lines) are USA lanlines , using rfc2833.
the called party not able to send DTMF, any way to resolve this?
Regards
devafree