I am running FreeSWITCH Version 1.6.6~64bit ( 64bit) running in a non-virtualized hardware platform. I am using it with FusionPBX (roughly 2 weeks since my last git pull) When using a SIP trunk from my CopperCom IP card I get intermittent duplicate DTMF digits specifically causing me trouble using the IVR application. With these options on: dtmf_verbose=true spandsp_dtmf_rx_threshold=-42 spandsp_dtmf_rx_twist=8 spandsp_dtmf_rx_reverse_twist=6 min_dup_digit_spacing_ms=50 (I have adjusted this from 0 to values of upwards of 2000...not sure it applies in this case as I think the duplicate digits might not be impacted by this value as I think two different systems are detecting the DTMF). In the following logs the min_dup_digit_spacing_ms might have been any number of values I was testing. So...on a properly recognized DTMF digit the logs look like this when I placed a test call to the IVR and dialed 9 as a menu option for the company directory then 489 to successfully to search for a name...in this call all worked as expected: b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:32:53.113751 [DEBUG] switch_core_media.c:4485 sofia/internal/541xxxyyyy@a.b.c.d Set 2833 dtmf send payload to 101 recv payload to 101 b6fe5cc0-717e-11e6-a586-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d parsing [public->dtmf-type] continue=true b6fe5cc0-717e-11e6-a586-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d Regex (PASS) [dtmf-type] () =~ // break=on-false b6fe5cc0-717e-11e6-a586-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d Action set(dtmf_verbose=true) b6fe5cc0-717e-11e6-a586-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d Action set(spandsp_dtmf_rx_threshold=-42) b6fe5cc0-717e-11e6-a586-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d Action set(spandsp_dtmf_rx_twist=8) b6fe5cc0-717e-11e6-a586-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d Action set(spandsp_dtmf_rx_reverse_twist=6) b6fe5cc0-717e-11e6-a586-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d Action spandsp_start_dtmf() b6fe5cc0-717e-11e6-a586-0360625ff113 EXECUTE sofia/internal/541xxxyyyy@a.b.c.d set(dtmf_verbose=true) b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:32:53.133718 [DEBUG] mod_dptools.c:1498 SET sofia/internal/541xxxyyyy@a.b.c.d [dtmf_verbose]=[true] b6fe5cc0-717e-11e6-a586-0360625ff113 EXECUTE sofia/internal/541xxxyyyy@a.b.c.d set(spandsp_dtmf_rx_threshold=-42) b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:32:53.133718 [DEBUG] mod_dptools.c:1498 SET sofia/internal/541xxxyyyy@a.b.c.d [spandsp_dtmf_rx_threshold]=[-42] b6fe5cc0-717e-11e6-a586-0360625ff113 EXECUTE sofia/internal/541xxxyyyy@a.b.c.d set(spandsp_dtmf_rx_twist=8) b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:32:53.133718 [DEBUG] mod_dptools.c:1498 SET sofia/internal/541xxxyyyy@a.b.c.d [spandsp_dtmf_rx_twist]=[8] b6fe5cc0-717e-11e6-a586-0360625ff113 EXECUTE sofia/internal/541xxxyyyy@a.b.c.d set(spandsp_dtmf_rx_reverse_twist=6) b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:32:53.133718 [DEBUG] mod_dptools.c:1498 SET sofia/internal/541xxxyyyy@a.b.c.d [spandsp_dtmf_rx_reverse_twist]=[6] b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:32:53.133718 [DEBUG] switch_core_session.c:2628 Application spandsp_start_dtmf Requires media! pre_answering channel sofia/internal/541xxxyyyy@a.b.c.d b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:32:53.133718 [DEBUG] switch_core_media.c:6332 sofia/internal/541xxxyyyy@a.b.c.d Set 2833 dtmf send payload to 101 b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:32:53.133718 [DEBUG] switch_core_media.c:6339 sofia/internal/541xxxyyyy@a.b.c.d Set 2833 dtmf receive payload to 101 b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:32:53.133718 [DEBUG] switch_core_media.c:6362 sofia/internal/541xxxyyyy@a.b.c.d Set rtp dtmf delay to 40 b6fe5cc0-717e-11e6-a586-0360625ff113 EXECUTE sofia/internal/541xxxyyyy@a.b.c.d spandsp_start_dtmf() b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:00.973723 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially D - total -18.52dB, row -35.24dB, col -32.15dB, duration 62628 - miss b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:00.993716 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -2.97dB, row -5.18dB, col -5.09dB, duration 62730 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:00.993716 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -2.94dB, row -5.03dB, col -5.06dB, duration 62832 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:00.993716 [DEBUG] mod_spandsp_dsp.c:375 DTMF BEGIN DETECTED: [9] b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:00.993716 [INFO] switch_channel.c:512 RECV DTMF 9:2000 b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:01.013719 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -3.03dB, row -5.21dB, col -5.28dB, duration 102 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:01.013719 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -3.02dB, row -5.29dB, col -5.13dB, duration 204 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:01.033720 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -2.92dB, row -5.03dB, col -5.03dB, duration 306 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:01.053716 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -2.97dB, row -5.08dB, col -5.22dB, duration 408 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:01.053716 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -9.02dB, row -17.52dB, col -16.96dB, duration 510 - miss b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:01.073716 [DEBUG] mod_spandsp_dsp.c:387 DTMF END DETECTED: [9], duration = 76 ms b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.093756 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially D - total -19.84dB, row -34.97dB, col -34.04dB, duration 48144 - miss b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.113726 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -2.80dB, row -4.77dB, col -4.77dB, duration 48246 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.113726 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -2.92dB, row -5.02dB, col -5.03dB, duration 48348 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.113726 [DEBUG] mod_spandsp_dsp.c:375 DTMF BEGIN DETECTED: [4] b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.113726 [INFO] switch_channel.c:512 RECV DTMF 4:2000 b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.133730 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -3.14dB, row -5.55dB, col -5.42dB, duration 102 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.133730 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -2.77dB, row -4.66dB, col -4.80dB, duration 204 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.153730 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -3.25dB, row -5.70dB, col -5.63dB, duration 306 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.173727 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -2.79dB, row -4.84dB, col -4.70dB, duration 408 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.173727 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -2.92dB, row -5.00dB, col -5.05dB, duration 510 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.193720 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -4.11dB, row -7.36dB, col -7.35dB, duration 612 - miss b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.213719 [DEBUG] mod_spandsp_dsp.c:387 DTMF END DETECTED: [4], duration = 89 ms b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.313724 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 8 - total -3.95dB, row -7.12dB, col -7.00dB, duration 918 - miss b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.333719 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 8 - total -3.10dB, row -5.44dB, col -5.32dB, duration 1020 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.353724 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 8 - total -2.99dB, row -5.15dB, col -5.16dB, duration 1122 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.353724 [DEBUG] mod_spandsp_dsp.c:375 DTMF BEGIN DETECTED: [8] b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.353724 [INFO] switch_channel.c:512 RECV DTMF 8:2000 b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.353724 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 8 - total -2.85dB, row -4.84dB, col -4.94dB, duration 102 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.373724 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 8 - total -2.90dB, row -5.02dB, col -4.93dB, duration 204 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.393724 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 8 - total -2.98dB, row -5.22dB, col -5.11dB, duration 306 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.393724 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 8 - total -3.11dB, row -5.32dB, col -5.43dB, duration 408 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.413724 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 8 - total -3.09dB, row -5.33dB, col -5.39dB, duration 510 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.413724 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially * - total -13.19dB, row -24.69dB, col -24.21dB, duration 612 - miss b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.433724 [DEBUG] mod_spandsp_dsp.c:387 DTMF END DETECTED: [8], duration = 89 ms b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.473724 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -9.05dB, row -17.46dB, col -17.13dB, duration 306 - miss b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.493719 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -2.97dB, row -5.12dB, col -5.12dB, duration 408 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.493719 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -2.96dB, row -5.16dB, col -5.06dB, duration 510 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.493719 [DEBUG] mod_spandsp_dsp.c:375 DTMF BEGIN DETECTED: [9] b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.493719 [INFO] switch_channel.c:512 RECV DTMF 9:2000 b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.513724 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -8.91dB, row -16.92dB, col -17.15dB, duration 102 - miss b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.533724 [DEBUG] mod_spandsp_dsp.c:387 DTMF END DETECTED: [9], duration = 25 ms b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.553724 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -5.06dB, row -9.31dB, col -9.33dB, duration 204 - miss b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.573734 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -2.98dB, row -5.04dB, col -5.19dB, duration 306 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.573734 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -2.93dB, row -5.14dB, col -4.99dB, duration 408 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.573734 [DEBUG] mod_spandsp_dsp.c:375 DTMF BEGIN DETECTED: [9] b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.573734 [INFO] switch_channel.c:512 RECV DTMF 9:2000 b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.593730 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -3.02dB, row -5.28dB, col -5.20dB, duration 102 - hit b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.593730 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 9 - total -11.08dB, row -21.34dB, col -21.19dB, duration 204 - miss b6fe5cc0-717e-11e6-a586-0360625ff113 2016-09-02 19:33:07.613728 [DEBUG] mod_spandsp_dsp.c:387 DTMF END DETECTED: [9], duration = 38 ms this time I dialed the same menu and dialed 4 and got invalid entry (which digit I dial to cause the intermittent failure seems to be nearly any digit): 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:18.513757 [DEBUG] switch_core_media.c:4485 sofia/internal/541xxxyyyy@a.b.c.d Set 2833 dtmf send payload to 101 recv payload to 101 0da6c076-717f-11e6-a732-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d parsing [public->dtmf-type] continue=true 0da6c076-717f-11e6-a732-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d Regex (PASS) [dtmf-type] () =~ // break=on-false 0da6c076-717f-11e6-a732-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d Action set(dtmf_verbose=true) 0da6c076-717f-11e6-a732-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d Action set(spandsp_dtmf_rx_threshold=-42) 0da6c076-717f-11e6-a732-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d Action set(spandsp_dtmf_rx_twist=8) 0da6c076-717f-11e6-a732-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d Action set(spandsp_dtmf_rx_reverse_twist=6) 0da6c076-717f-11e6-a732-0360625ff113 Dialplan: sofia/internal/541xxxyyyy@a.b.c.d Action spandsp_start_dtmf() 0da6c076-717f-11e6-a732-0360625ff113 EXECUTE sofia/internal/541xxxyyyy@a.b.c.d set(dtmf_verbose=true) 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:18.513757 [DEBUG] mod_dptools.c:1498 SET sofia/internal/541xxxyyyy@a.b.c.d [dtmf_verbose]=[true] 0da6c076-717f-11e6-a732-0360625ff113 EXECUTE sofia/internal/541xxxyyyy@a.b.c.d set(spandsp_dtmf_rx_threshold=-42) 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:18.513757 [DEBUG] mod_dptools.c:1498 SET sofia/internal/541xxxyyyy@a.b.c.d [spandsp_dtmf_rx_threshold]=[-42] 0da6c076-717f-11e6-a732-0360625ff113 EXECUTE sofia/internal/541xxxyyyy@a.b.c.d set(spandsp_dtmf_rx_twist=8) 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:18.513757 [DEBUG] mod_dptools.c:1498 SET sofia/internal/541xxxyyyy@a.b.c.d [spandsp_dtmf_rx_twist]=[8] 0da6c076-717f-11e6-a732-0360625ff113 EXECUTE sofia/internal/541xxxyyyy@a.b.c.d set(spandsp_dtmf_rx_reverse_twist=6) 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:18.513757 [DEBUG] mod_dptools.c:1498 SET sofia/internal/541xxxyyyy@a.b.c.d [spandsp_dtmf_rx_reverse_twist]=[6] 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:18.513757 [DEBUG] switch_core_session.c:2628 Application spandsp_start_dtmf Requires media! pre_answering channel sofia/internal/541xxxyyyy@a.b.c.d 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:18.533724 [DEBUG] switch_core_media.c:6332 sofia/internal/541xxxyyyy@a.b.c.d Set 2833 dtmf send payload to 101 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:18.533724 [DEBUG] switch_core_media.c:6339 sofia/internal/541xxxyyyy@a.b.c.d Set 2833 dtmf receive payload to 101 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:18.533724 [DEBUG] switch_core_media.c:6362 sofia/internal/541xxxyyyy@a.b.c.d Set rtp dtmf delay to 40 0da6c076-717f-11e6-a732-0360625ff113 EXECUTE sofia/internal/541xxxyyyy@a.b.c.d spandsp_start_dtmf() 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:22.593744 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -4.41dB, row -8.03dB, col -8.02dB, duration 32538 - miss 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:22.593744 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -2.73dB, row -4.71dB, col -4.59dB, duration 32640 - hit 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:22.693734 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -4.19dB, row -7.59dB, col -7.55dB, duration 33354 - miss 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:22.713723 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -3.25dB, row -5.68dB, col -5.62dB, duration 33456 - hit 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:22.713723 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -2.76dB, row -4.65dB, col -4.79dB, duration 33558 - hit 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:22.713723 [DEBUG] mod_spandsp_dsp.c:375 DTMF BEGIN DETECTED: [4] 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:22.713723 [INFO] switch_channel.c:512 RECV DTMF 4:2000 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:22.733724 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -3.18dB, row -5.61dB, col -5.47dB, duration 102 - hit 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:22.753724 [DEBUG] switch_rtp.c:6874 RTP RECV DTMF 4:800 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:22.753724 [INFO] switch_channel.c:512 RECV DTMF 4:800 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:22.753724 [DEBUG] mod_spandsp_fax.c:276 FLOW DTMF Potentially 4 - total -3.76dB, row -6.65dB, col -6.69dB, duration 204 - hit 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:22.793718 [DEBUG] mod_spandsp_dsp.c:387 DTMF END DETECTED: [4], duration = 51 ms Whenever I have problems with duplicate digits as in the later example above I always get a line with switch_rtp.c like this: 0da6c076-717f-11e6-a732-0360625ff113 2016-09-02 19:35:22.753724 [DEBUG] switch_rtp.c:6874 RTP RECV DTMF 4:800 If one of the switch_rtp lines does not show up in the output put that it RECV DTMF the DTMF is recognized properly. Is there an option that I can set to tell the switch_rtp.c to ignore receiving DTMF? I do not know happens that causes some calls to work and some calls to not work. I was not sure if when it is intermittent (sometimes 80% get duplicate DTMF, sometimes only 20% get duplicate DTMF) what else to try. I saw this: https://freeswitch.org/confluence/display/FREESWITCH/RTP+Issues and was not sure if this applied...or where options like: <param name="auto-rtp-bugs" value="clear"/> Were supposed to be placed in the dial plan to get these in the right place. Is this part of the options before you invoke action=spandsp_start_dtmf Thanks in advance for any help you can provide. Jeff -.-. --.- -.. . -.- . --... --.- -.-- ..-