Hi Michael,
Below is the snippet of the freeswitch log.
Success Call :
2013-01-16 00:58:58.314163 [DEBUG] switch_rtp.c:3797 RTP RECV DTMF 9:640
2013-01-16 00:58:58.314163 [DEBUG] ftdm_io.c:3038 [s4c1][4:1] Created DTMF buffer
2013-01-16 00:58:58.314163 [DEBUG] switch_ivr_bridge.c:393 Send signal FreeTDM/4:1/2001 [BREAK]
2013-01-16 00:58:58.314163 [DEBUG] ftdm_io.c:3979 [s4c1][4:1] Generating DTMF [9]
2013-01-16 00:59:06.414163 [DEBUG] switch_rtp.c:3797 RTP RECV DTMF 1:640
2013-01-16 00:59:06.414163 [DEBUG] switch_ivr_bridge.c:393 Send signal FreeTDM/4:1/2001 [BREAK]
2013-01-16 00:59:06.414163 [DEBUG] ftdm_io.c:3979 [s4c1][4:1] Generating DTMF [1]
2013-01-16 00:59:06.774163 [DEBUG] switch_rtp.c:3797 RTP RECV DTMF 9:640
2013-01-16 00:59:06.774163 [DEBUG] switch_ivr_bridge.c:393 Send signal FreeTDM/4:1/2001 [BREAK]
2013-01-16 00:59:06.774163 [DEBUG] ftdm_io.c:3979 [s4c1][4:1] Generating DTMF [9]
2013-01-16 00:59:09.214164 [DEBUG] ftmod_wanpipe.c:1678 [s4c1][4:1] read wanpipe event 3
2013-01-16 00:59:09.254162 [DEBUG] ftmod_wanpipe.c:1678 [s4c1][4:1] read wanpipe event 3
2013-01-16 00:59:09.254162 [DEBUG] ftmod_wanpipe.c:1547 [s4c1][4:1] Queuing wanpipe DTMF: 7
2013-01-16 00:59:09.254162 [DEBUG] ftdm_io.c:3783 [s4c1][4:1] Queuing DTMF 7 (debug = 0)
2013-01-16 00:59:09.254162 [DEBUG] mod_freetdm.c:811 Queuing DTMF [7] in channel FreeTDM/4:1/2001 device 4:1
2013-01-16 00:59:09.254162 [DEBUG] switch_ivr_bridge.c:393 Send signal sofia/VOIPBRD1/2001@**.**.**.** [BREAK]
2013-01-16 00:59:09.514163 [DEBUG] switch_rtp.c:2589 Queue digit delay of 40ms
2013-01-16 00:59:09.594164 [DEBUG] ftmod_wanpipe.c:1678 [s4c1][4:1] read wanpipe event 3
2013-01-16 00:59:09.654166 [DEBUG] ftmod_wanpipe.c:1678 [s4c1][4:1] read wanpipe event 3
2013-01-16 00:59:09.654166 [DEBUG] ftmod_wanpipe.c:1547 [s4c1][4:1] Queuing wanpipe DTMF: 1
2013-01-16 00:59:09.654166 [DEBUG] ftdm_io.c:3783 [s4c1][4:1] Queuing DTMF 1 (debug = 0)
2013-01-16 00:59:09.674165 [DEBUG] mod_freetdm.c:811 Queuing DTMF [1] in channel FreeTDM/4:1/2001 device 4:1
2013-01-16 00:59:09.674165 [DEBUG] switch_ivr_bridge.c:393 Send signal sofia/VOIPBRD1/2001@**.**.**.** [BREAK]
013-01-16 00:59:09.934163 [DEBUG] switch_rtp.c:2589 Queue digit delay of 40ms
2013-01-16 00:59:11.234163 [DEBUG] switch_rtp.c:3797 RTP RECV DTMF 9:640
2013-01-16 00:59:11.234163 [DEBUG] switch_ivr_bridge.c:393 Send signal FreeTDM/4:1/2001 [BREAK]
2013-01-16 00:59:11.234163 [DEBUG] ftdm_io.c:3979 [s4c1][4:1] Generating DTMF [9]
2013-01-16 00:59:11.394163 [DEBUG] switch_rtp.c:3797 RTP RECV DTMF 9:640
2013-01-16 00:59:11.394163 [DEBUG] switch_ivr_bridge.c:393 Send signal FreeTDM/4:1/2001 [BREAK]
2013-01-16 00:59:11.394163 [DEBUG] ftdm_io.c:3979 [s4c1][4:1] Generating DTMF [9]
Failed DTMF call :
2013-01-16 01:02:27.694163 [DEBUG] switch_rtp.c:3797 RTP RECV DTMF 9:640
2013-01-16 01:02:27.694163 [DEBUG] switch_ivr_bridge.c:393 Send signal FreeTDM/4:1/2001 [BREAK]
2013-01-16 01:02:27.694163 [DEBUG] ftdm_io.c:3979 [s4c1][4:1] Generating DTMF [9]
2013-01-16 01:02:32.834164 [INFO] ftmod_sangoma_isdn_stack_rcv.c:232 [s4c1][4:1] Received DISCONNECT (suId:1 suInstId:2 spInstId:2)
2013-01-16 01:02:32.834164 [DEBUG] ftmod_sangoma_isdn_stack_hndl.c:543 [s4c1][4:1] Processing DISCONNECT (suId:1 suInstId:2
Thanks,
Subhash.