Interpreting DTMF logs format

Asterisk Asterisk Support
1

I have build a system where 2 parties in conference can perform certain functions via DTMF tones while in conversation with each other.
I have picked up that randomly during the day certain DTMF digits are not processed via AGI. On closer inspection I found that the DTMF digits are processed by the pbx but never gets to the AGI part.
After close scrutiny it became apparent that the digits not reaching AGI are those with the following field (in bold) somehow changed. My question is what is this field and why did it change?

Successful Digits to AGI:

[2016-02-01 15:27:01] DTMF[24132][C-0000002c] channel.c: DTMF begin ‘5’ received on SIP/ast2-00000039
[2016-02-01 15:27:01] DTMF[24132][C-0000002c] channel.c: DTMF begin passthrough ‘5’ on SIP/ast2-00000039
[2016-02-01 15:27:01] DTMF[24132][C-0000002c] channel.c: DTMF end ‘5’ received on SIP/ast2-00000039, duration 140 ms
[2016-02-01 15:27:01] DTMF[24132][C-0000002c] channel.c: DTMF end accepted with begin ‘5’ on SIP/ast2-00000039
[2016-02-01 15:27:01] DTMF[24132][C-0000002c] channel.c: DTMF end passthrough ‘5’ on SIP/ast2-00000039

[2016-02-01 15:27:03] DTMF[24132][C-0000002c] channel.c: DTMF begin ‘6’ received on SIP/ast2-00000039
[2016-02-01 15:27:03] DTMF[24132][C-0000002c] channel.c: DTMF begin passthrough ‘6’ on SIP/ast2-00000039
[2016-02-01 15:27:03] DTMF[24132][C-0000002c] channel.c: DTMF end ‘6’ received on SIP/ast2-00000039, duration 80 ms
[2016-02-01 15:27:03] DTMF[24132][C-0000002c] channel.c: DTMF end accepted with begin ‘6’ on SIP/ast2-00000039
[2016-02-01 15:27:03] DTMF[24132][C-0000002c] channel.c: DTMF end passthrough ‘6’ on SIP/ast2-00000039

Missing digit to AGI:
[2016-02-01 15:27:04] DTMF[24132][C-0000002c] channel.c: DTMF begin ‘6’ received on SIP/ast2-00000039
[2016-02-01 15:27:04] DTMF[24132][C-0000002c] channel.c: DTMF begin passthrough ‘6’ on SIP/ast2-00000039
[2016-02-01 15:27:04] DTMF[2636][C-0000002c] channel.c: DTMF end ‘6’ received on SIP/ast2-00000039, duration 80 ms
[2016-02-01 15:27:04] DTMF[2636][C-0000002c] channel.c: DTMF end accepted with begin ‘6’ on SIP/ast2-00000039
[2016-02-01 15:27:04] DTMF[2636][C-0000002c] channel.c: DTMF end passthrough ‘6’ on SIP/ast2-00000039

Many thanks to anyone that can shed some insight.

2

That’s a thread ID. Did the AGI process get stuck briefly?

3

The agi keep processing all other digits except the ones with the changed ID, it seems to never get the dtmf digit passthru although the core processes the digit received but changes the ID (in bold) halfway through the receive process. and this I think is why AGI ignores the digit.