Here is a sample wireshark event capture of the relevant areas: 6590 31.159045000 xx.x.x.xxx -.-.-.- RTP EVENT Payload type=RTP Event, DTMF Pound # (end)ġ0. In section 3.8, codes 96 and 97 are described as 'the dynamic payload types 96 and 97 have been assigned for the redundancy mechanism and the telephone event payload respectively'Ģ) In section 3.5, 'E:', 'A sender MAY delay setting the end bit until retransmitting the last packet for a tone, rather than on its first transmission' Does anyone have an idea of how to actually do this?ģ) I have a separate output stream that also plays so wonder if it might be interfering with hearing this stream.Ĥ) have also fiddled around with timestamp intervals and the RTP marker.Īny help is greatly appreciated. I have thought of some possible causes but do not know if they are the reason:ġ) figure 2 shows payload types of 96 and 97 sent. When I set the 'E' bit to 1 for all numbers, I never get an event to sound. In section 3.9, figure 2 of the above linked document, they give a 911 example where all but the last event have the E bit set. So the first key (which I figure could be a separate issue) and any repeats of an event (ie 11111) are failing to sound. If for example keys 7874556332111111145855885#3 are pressed, then ALL events are sent and show up in a program like wireshark, however only 87456321458585#3 sound. Obtaining the following behaviour when the E bit is NOT set: I can send out a RFC 2833 dtmf event as outlined at

Why do I get a dtmf sound when the E bit is 0 and no sound when it is 1? (RTP packets appear in wireshark either way) Background:

Dtmf rfc2833