E911 Signalling

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We’ve got a dedicated T1 with two trunks running into our ILECs selective router for 911. Split out of the T1 into two MF CAMA trunks on ILEC side.

I’m trying to use asterisks e911 signaling, but I’m having trouble with the dial command. (== Everyone is busy/congested at this time (1:1/0/0))

I’m missing something and I’m thinking it has to do with the hookstate of the dahdi channel.

If anyone has a similar situation and want to provide some guidance, I’d sure appreciate it.



Here’s my config:

DAHDI version

[root@e911 dahdi]# dahdi_hardware

pci:0000:02:01.0 wct1xxp+ e159:0001 Digium Wildcard T100P T1/PRI
or E100P E1/PRA Board

e911*CLI> core show version

Asterisk 11.7.0 built by root @ e911 on a x86_64 running Linux on
2014-01-28 15:50:19 UTC











exten => s,1,dial(DAHDI/1/${CALLERID(num)})

e911*CLI> dahdi show status

Description Alarms IRQ bpviol CRC
Fra Codi Options LBO

Digium Wildcard T100P T1/PRI Card 0 OK 0 0 0
ESF B8ZS 0 db (CSU)/0-133 feet (DSX-1)

e911*CLI> dahdi show channels

Chan Extension Context Language MOH Interpret Blocked State Description

pseudo default default In Service

1 public default In Service

2 public default In Service

e911*CLI> dahdi show channel 1

Channel: 1


File Descriptor: 7

Span: 1


Dialing: no

Context: public

Caller ID:

Calling TON: 0

Caller ID name:

Mailbox: none

Destroy: 0

InAlarm: 0

Signalling Type: E911 (MF)

Radio: 0





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): Offhook

Here’s a debug from a 911 call.

[Jan 31 11:29:53] DEBUG[9876][C-00000005]: pbx.c:4890
pbx_extension_helper: Launching ‘Dial’

— Executing [s@InFromSIP:1] Dial(“SIP/SIP-00000005”,
“DAHDI/1/2177772001”) in new stack

[Jan 31 11:29:53] DEBUG[9876][C-00000005]: sig_analog.c:820
analog_available: analog_available 1

[Jan 31 11:29:53] DEBUG[9876][C-00000005]: sig_analog.c:845
analog_available: Channel 1 off hook, can’t use

[Jan 31 11:29:53] WARNING[9876][C-00000005]: app_dial.c:2437
dial_exec_full: Unable to create channel of type ‘DAHDI’ (cause 17 –
User busy)

== Everyone is busy/congested at this time (1:1/0/0)

[Jan 31 11:29:53] DEBUG[9876][C-00000005]: app_dial.c:3100
dial_exec_full: Exiting with DIALSTATUS=BUSY.

— Auto fallthrough, channel ‘SIP/SIP-00000005’ status is ‘BUSY’