Pulse dialing on e&m - pulses interpreted as hangups

We’re trying to integrate some outside world functionality on a phone museum’s step-by-step central office. This mechanical office has CAMA equipment that uses a 4-Wire E&M trunk interface. We plan to use this arrangement for calls going from the mechanical office to the outside world (Asterisk). Through channel bank, etc, channel 23 of the Asterisk T1 interface is connected to this equipment. The CAMA equipment was successfully connected to and used with a carrier’s electronic central office but that connection is no longer available to us.

The CAMA equipment uses the FGC/CAMA protocol - seize trunk toward the other central office (Asterisk), send dialed number in dial pulse, get seizure from the other central office (Asterisk), send ANI using MF.

The Asterisk sees the off-hook when calls try to get to it on this trunk but the pulse dialing that follows is being seen as hang-ups instead of call digits. How do we get the Asterisk to recognize pulse dialing on a T1-delivered FGC/CAMA trunk? We also tried pulse dialing with E&M signalling and experienced the same result.

Anyone done a T1-delivered E&M dial pulse Asterisk integration?

Asterisk version 1.8.4.3
T1 card = TE110P

Here is a log excerpt from a call attempt while the channel’s signalling was set to “em”:

[Feb 18 19:42:51] VERBOSE[3033] sig_analog.c: – Starting simple switch on ‘DAHDI/23-1’
[Feb 18 19:42:54] VERBOSE[3033] file.c: – <DAHDI/23-1> Playing ‘ss-noservice.ulaw’ (language ‘en’)
[Feb 18 19:42:54] VERBOSE[3033] sig_analog.c: – Hanging up on ‘DAHDI/23-1’
[Feb 18 19:42:54] VERBOSE[3033] chan_dahdi.c: – Hungup ‘DAHDI/23-1’
[Feb 18 19:42:54] VERBOSE[3035] sig_analog.c: – Starting simple switch on ‘DAHDI/23-1’
[Feb 18 19:42:57] VERBOSE[3035] file.c: – <DAHDI/23-1> Playing ‘ss-noservice.ulaw’ (language ‘en’)
[Feb 18 19:42:57] VERBOSE[3035] sig_analog.c: – Hanging up on ‘DAHDI/23-1’
[Feb 18 19:42:57] VERBOSE[3036] sig_analog.c: – Starting simple switch on ‘DAHDI/23-1’
[Feb 18 19:42:57] VERBOSE[3035] chan_dahdi.c: – Hungup ‘DAHDI/23-1’
[Feb 18 19:43:00] VERBOSE[3036] file.c: – <DAHDI/23-1> Playing ‘ss-noservice.ulaw’ (language ‘en’)
[Feb 18 19:43:00] VERBOSE[3036] sig_analog.c: – Hanging up on ‘DAHDI/23-1’
[Feb 18 19:43:00] VERBOSE[3036] chan_dahdi.c: – Hungup ‘DAHDI/23-1’
[Feb 18 19:43:00] VERBOSE[3037] sig_analog.c: – Starting simple switch on ‘DAHDI/23-1’
[Feb 18 19:43:03] VERBOSE[3037] file.c: – <DAHDI/23-1> Playing ‘ss-noservice.ulaw’ (language ‘en’)
[Feb 18 19:43:03] VERBOSE[3037] sig_analog.c: – Hanging up on ‘DAHDI/23-1’
[Feb 18 19:43:03] VERBOSE[3037] chan_dahdi.c: – Hungup ‘DAHDI/23-1’
[Feb 18 19:43:03] VERBOSE[3038] sig_analog.c: – Starting simple switch on ‘DAHDI/23-1’
[Feb 18 19:43:06] VERBOSE[3038] file.c: – <DAHDI/23-1> Playing ‘ss-noservice.ulaw’ (language ‘en’)
[Feb 18 19:43:06] VERBOSE[3038] sig_analog.c: – Hanging up on ‘DAHDI/23-1’
[Feb 18 19:43:06] VERBOSE[3038] chan_dahdi.c: – Hungup ‘DAHDI/23-1’

Here is the dahdi config. The PRI portion (chans 1-8 and 24) works perfectly. Channel 23 is the trunk in question. We tried using signalling=fgccama (which most accurately describes the protocol of this device - DP DNIS, MF ANI) but it also suffers from the same problem.

context=from-pstn
switchtype=qsig
nsf=none
immediate=no
faxdetect=incoming
facilityenable=yes
hidecalleridname=no
usecallerid=yes
usecallingpres=yes
restrictcid=no
callerid=asreceived
useincomingcalleridondahditransfer=yes
echocancel=yes
echocancelwhenbridged=yes
echotraining=800
wink=200
debounce=100
flash=300
toneduration=100
starttime=750
group=0
signalling=pri_cpe
channel => 1-8

context=from-museum-cama
group=1
signalling=em (was fgccama in other testing)
immediate=yes
channel => 23

Logs from start-up, first with signalling=fgccama and then with signalling=em:

[Feb 18 19:31:17] VERBOSE[2877] chan_dahdi.c: – Registered channel 23, FGC/CAMA (Dialpulse) signalling

[Feb 18 19:42:28] VERBOSE[2992] chan_dahdi.c: – Registered channel 23, E & M Immediate signalling

Output from dahdi show channel 23:

asteriskCLI> dahdi show channel 23
Channel: 23
File Descriptor: 18
Span: 1
Extension:
Dialing: no
Context: from-museum-cama
Caller ID:
Calling TON: 0
Caller ID subaddress:
Caller ID name:
Mailbox: none
Destroy: 0
InAlarm: 0
Signalling Type: E & M Immediate
Radio: 0
Owner:
Real:
Callwait:
Threeway:
Confno: -1
Propagated Conference: -1
Real in conference: 0
DSP: no
Busy Detection: no
TDD: no
Relax DTMF: no
Dialing/CallwaitCAS: 0/0
Default law: ulaw
Fax Handled: no
Pulse phone: no
Gains (RX/TX): 0.00/0.00
Dynamic Range Compression (RX/TX): 0.00/0.00
DND: no
Echo Cancellation:
128 taps
currently OFF
Wait for dialtone: 0ms
Actual Confinfo: Num/0, Mode/0x0000
Actual Confmute: No
Hookstate (FXS only): Onhook
asterisk
CLI>

No ideas?

Assuming the card is genuine, take a look at the sticky, first, post in the forum.