I'm encountering a peculiar issue regarding DTMF. DTMF tones are not always being recognized by our call center, this problem seems to coincide with out recent IOS upgrade on our MGCP gateway. Most calls from outside of our organization, when calling our call center from within, are able to send DTMF with no problems. However, other phones are not. There doesn't seem to be a connection between the problem calls; the phones having trouble are both cell and land lines, within the same exchange and from without, etc. Also, DTMF is being sent out of band in the MGCP syntax.
My question is; is there a setting to adjust DTMF settings on the gateway? I suspect that the DTMF is not being recognized because it may not be loud enough or the tone sent may be too brief.