DTMF duplicate when RTP event have long delay between packets

[olajansson]

Has problems with DTMF duplicate when the RTP event packets are delayed by about 0.4 seconds.

Press 609 but Asterisk detect 600009

Asterisk 11.6

Asterisk log.

[Dec 3 07:02:38] DTMF[29838][C-000ef3b0] channel.c: DTMF begin ‘6’ received on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:38] DTMF[29838][C-000ef3b0] channel.c: DTMF begin ignored ‘6’ on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:39] DTMF[29838][C-000ef3b0] channel.c: DTMF end ‘6’ received on SIP/upps-ccm-tq01-00207e90, duration 250 ms
[Dec 3 07:02:39] DTMF[29838][C-000ef3b0] channel.c: DTMF end passthrough ‘6’ on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:39] DTMF[29838][C-000ef3b0] channel.c: DTMF begin ‘0’ received on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:39] DTMF[29838][C-000ef3b0] channel.c: DTMF begin ignored ‘0’ on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:39] DTMF[29838][C-000ef3b0] channel.c: DTMF end ‘0’ received on SIP/upps-ccm-tq01-00207e90, duration 100 ms
[Dec 3 07:02:39] DTMF[29838][C-000ef3b0] channel.c: DTMF end passthrough ‘0’ on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF begin ‘0’ received on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF begin ignored ‘0’ on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF end ‘0’ received on SIP/upps-ccm-tq01-00207e90, duration 150 ms
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF end passthrough ‘0’ on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF begin ‘0’ received on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF begin ignored ‘0’ on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF end ‘0’ received on SIP/upps-ccm-tq01-00207e90, duration 200 ms
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF end passthrough ‘0’ on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF end ‘0’ received on SIP/upps-ccm-tq01-00207e90, duration 250 ms
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF end passthrough ‘0’ on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF begin ‘9’ received on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF begin ignored ‘9’ on SIP/upps-ccm-tq01-00207e90
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF end ‘9’ received on SIP/upps-ccm-tq01-00207e90, duration 250 ms
[Dec 3 07:02:40] DTMF[29838][C-000ef3b0] channel.c: DTMF end passthrough ‘9’ on SIP/upps-ccm-tq01-00207e90

Wireshark

[ambiorixg12]

What codec are you using ?
low-bit-rate codecs such as G.729 and G.723.1 are highly optimized for voice patterns and tend to distort DTMF tones.

As you have issues with RTP delay you can try SIP INFO for the dtmf