[asterisk-r2] DTMF issue after migrating Unicall -> OpenR2

[Norman Schmidt]

After a straighforward migration from Unicall (astunicall-1.4.9-0.1.tar.gz)
to OpenR2 1.1.0, and a simple conversion of unicall.conf to zapata.conf, at
first sight everything worked on a production Asterisk server acting as a
recording gateway between the telco and a legacy PBX system (Digitro).
Yesterday I noticed that DTMF tones are not working as before. There is an
IVR at the legacy PBX system, and calls are being completed between telco
and Asterisk, and between Asterisk and the legacy PBX, but any DTMF tones
generated by the caller at this point are not passed anymore to the legacy
PBX, generating this at console debug:

[Apr 20 12:01:54] NOTICE[1984]: chan_zap.c:961 zt_r2_on_call_init: New
MFC/R2 call detected on chan 1.
[Apr 20 12:02:01] NOTICE[1984]: chan_zap.c:1025 zt_r2_on_call_offered:
MFC/R2 call offered on chan 1. ANI = 5132221234, DNIS = 525, Category =
National Subscriber  
[Apr 20 12:02:02] NOTICE[1984]: chan_zap.c:1093 zt_r2_on_call_accepted:
MFC/R2 call has been accepted on chan 1
[Apr 20 12:02:02]     -- Executing [525 at from-brt:1] Set("Zap/1-1",
"ARQUIVO=20042009_1202_e_5132221234_525.gsm") in new stack
[Apr 20 12:02:02]     -- Executing [525 at from-brt:2] MixMonitor("Zap/1-1",
"20042009_1202_e_5132221234_525.gsm|baW(0)") in new stack
[Apr 20 12:02:02]     -- Executing [525 at from-brt:3] Dial("Zap/1-1",
"Zap/g3/525|120|tTwW") in new stack
[Apr 20 12:02:02]     -- Called g3/525
[Apr 20 12:02:02]   == Begin MixMonitor Recording Zap/1-1
[Apr 20 12:02:05] NOTICE[3679]: chan_zap.c:1093 zt_r2_on_call_accepted:
MFC/R2 call has been accepted on chan 94
[Apr 20 12:02:05] NOTICE[3679]: chan_zap.c:1109 zt_r2_on_call_accepted: Call
accepted on forward channel 94
[Apr 20 12:02:05]     -- Zap/94-1 is ringing
[Apr 20 12:02:05] WARNING[3679]: translate.c:175 framein: no samples for
alawtolin
[Apr 20 12:02:10]     -- Zap/94-1 answered Zap/1-1
[Apr 20 12:02:22] DTMF[3679]: channel.c:2116 __ast_read: DTMF end '1'
received on Zap/1-1, duration 0 ms
[Apr 20 12:02:22] DTMF[3679]: channel.c:2152 __ast_read: DTMF begin
emulation of '1' with duration 100 queued on Zap/1-1
[Apr 20 12:02:22] DTMF[3679]: channel.c:2261 __ast_read: DTMF end emulation
of '1' queued on Zap/1-1
[Apr 20 12:02:22] WARNING[3679]: chan_zap.c:1532 zt_digit_begin: Couldn't
dial digit 1
[Apr 20 12:02:23] NOTICE[1990]: chan_zap.c:961 zt_r2_on_call_init: New
MFC/R2 call detected on chan 95.
[Apr 20 12:02:24] DTMF[3679]: channel.c:2116 __ast_read: DTMF end '1'
received on Zap/1-1, duration 0 ms
[Apr 20 12:02:24] DTMF[3679]: channel.c:2152 __ast_read: DTMF begin
emulation of '1' with duration 100 queued on Zap/1-1
[Apr 20 12:02:24] DTMF[3679]: channel.c:2261 __ast_read: DTMF end emulation
of '1' queued on Zap/1-1
[Apr 20 12:02:24] WARNING[3679]: chan_zap.c:1532 zt_digit_begin: Couldn't
dial digit 1
[Apr 20 12:02:26] NOTICE[1990]: chan_zap.c:961 zt_r2_on_call_init: New
MFC/R2 call detected on chan 96.
[Apr 20 12:02:26] NOTICE[3679]: chan_zap.c:1153 zt_r2_on_call_disconnect:
MFC/R2 call disconnected on chan 1
[Apr 20 12:02:26]     -- Hungup 'Zap/94-1'
[Apr 20 12:02:26]   == Spawn extension (from-brt, 525, 3) exited non-zero on
'Zap/1-1'
[Apr 20 12:02:26] NOTICE[3679]: chan_zap.c:1064 zt_r2_on_call_end: MFC/R2
call end on chan 1
[Apr 20 12:02:26]     -- Hungup 'Zap/1-1'
[Apr 20 12:02:26]   == End MixMonitor Recording Zap/1-1
[Apr 20 12:02:26] NOTICE[1990]: chan_zap.c:1064 zt_r2_on_call_end: MFC/R2
call end on chan 94

ZAP/1-1 is a channel on the TELCO side of the recording gateway. The DTMF
tone IS generated INBAND, and the caller can hear it, but it seems that
nothing arrives at the legacy PBX. 525 is the extension at the legacy PBX
which is called to get its IVR on the internal leg of the gateway (group 3).
Any clue or starting point? Is this related to the zaptel OpenR2 patch?

my zapata.conf:

[channels]
language=br
usecallerid=yes
callwaitingcallerid=yes
threewaycalling=yes
hidecallerid=no
transfer=yes
canpark=yes
cancallforward=yes
callreturn=yes
echocancel=yes
echocancelwhenbridged=yes
echotraining=yes
relaxdtmf=yes
rxgain=0
txgain=0
immediate=no
musiconhold=default
loglevel=0

signalling=mfcr2

context=from-brt
mfcr2_variant=br
mfcr2_get_ani_first=no
mfcr2_category=national_subscriber
mfcr2_max_ani=20
mfcr2_max_dnis=20
group=0
channel => 1-15,17-31       

context=from-digitro-brt
mfcr2_variant=br
mfcr2_max_ani=20
mfcr2_max_dnis=20
group=3
channel => 94-108,110-124     

Norman