DTMF timing on FXS port

[freiselt]

We have a customer that is using an Atlas 550 with a PRI on the network card and an octal FXS card going to an octal modem card in a FAX server. We have it set up to take the last 4 digits of the DID numbers and send it via DTMF from the FXS card to the modem.  The DTMF digits are measuring 70ms tone and 70 ms interdigit gap.  The modem is occasionally missing digits. The modem manufacturer states that they want 100ms DTMF tone and 100ms interdigit gap. Is there a way to change the DTMF timing in the Atlas 500 to meet the modem requirement?

[Anonymous · Accepted solution]

We have measured the digit duration and interdigit delay to be 75ms, so your measurement of 70ms is accurate. Neither of these are configurable on the ATLAS, however the interdigit delay can be manipulated under the DIAL PLAN in the SUBSTITUTION TEMPLATE to some extent. A comma (,) can be used to introduce a 1/2 second delay, but you cannot put a comma between variables in the SUB TEMPLATE - only specific digits. So you can add a 1/2 second interdigit delay with an original DNIS of "1234" and a substituted DNIS of "1,2,3,4", but you cannot use an original DNIS of "XXXX" and a substituted DNIS of "X,X,X,X".

Thank you,

Patrick