[VoIP] In-Band Signaling

[John R. Covert]

>I'm pretty sure you won't be able to tell the difference.

What you will notice (and this is actually a bug, but it's cool) is
that Asterisk will convert any DTMF sent by a caller to a called party
on an MF trunk group into MF even after the call is established.

This can be demonstrated by calling into the Wawina Loop-Around,
via CNET.  This is an Asterisk MF trunk group.   Then call into the
other side.  Touch-tone will be converted to MF during the call.

/john