Found this resource when searching for “stutter dial tone”. It contains the frequency and cadence definitions for the tones – could be quite useful if you are in VoIP business. Click to explore World PSTN Tone Database.

X-Lite can send 3 different types of DTMF, and you need to know which to use or to try all methods: In-band DTMF RTP telephone-event per RFC 2833 SIP INFO per RFC 2976 This is the most likely solution: Dial ***7469 (send) Once you get the advanced options menu up, filter first for DTMF. Find [...]