However, the digits are not collected (sometimes this scenario works OK but I cannot identify a pattern), as can be seen from the logs below:
EXECUTE sofia/test/2001@test flush_dtmf()
2015-05-15 07:09:39.694302 [DEBUG] mod_erlang_event.c:169 Ignoring event CHANNEL_EXECUTE for attached session d7e76764-faf2-11e4-8f50- 771905ed12f6
2015-05-15 07:09:39.694302 [DEBUG] mod_erlang_event.c:169 Ignoring event CHANNEL_EXECUTE_COMPLETE for attached session d7e76764-faf2-11e4-8f50- 771905ed12f6
2015-05-15 07:09:39.694302 [INFO] switch_cpp.cpp:1291 UUID: d7e76764-faf2-11e4-8f50- 771905ed12f6
2015-05-15 07:09:39.714301 [NOTICE] switch_cpp.cpp:1291 1234 Before GetDigits
2015-05-15 07:09:42.034319 [DEBUG] switch_rtp.c:5788 RTP RECV DTMF 1:1120
2015-05-15 07:09:42.034319 [DEBUG] switch_channel.c:486 RECV DTMF 1:1120
2015-05-15 07:09:42.034319 [DEBUG] mod_dptools.c:2138 Digit 1
2015-05-15 07:09:42.034319 [DEBUG] mod_erlang_event.c:157 Sending event DTMF to attached session d7e76764-faf2-11e4-8f50- 771905ed12f6
2015-05-15 07:09:49.714345 [DEBUG] switch_cpp.cpp:838 getDigits dtmf_buf:
2015-05-15 07:09:49.714345 [NOTICE] switch_cpp.cpp:1291 1234 AFTER GetDigits
EXECUTE sofia/test/2001@test flush_dtmf()
2015-05-15 07:09:49.714345 [DEBUG] mod_erlang_event.c:169 Ignoring event CHANNEL_EXECUTE for attached session d7e76764-faf2-11e4-8f50- 771905ed12f6
2015-05-15 07:09:49.714345 [NOTICE] switch_cpp.cpp:1291 flush DTMF 2
2015-05-15 07:09:49.714345 [NOTICE] switch_cpp.cpp:1291 After Get Digits
2015-05-15 07:09:49.714345 [NOTICE] switch_cpp.cpp:1291 digits =