Outboud dialling often fails to recognise number

We have 3 lines with BT. Lines 1 & 2 have the same PSTN number and are configured as a group to use round robin for outbound calls. We don’t use line 3 for outbound calls normally. The shared number is the BT auxiliary line feature and not a featureline, nor compact+ service. When we dial out we get a very inconsistent problem with numbers not being recognised. We get a BT prerecorded message “The number you have dialled has not been recognised. Please hang-up and try again” (or similar). If we hit the redial button a few more times it eventually connects the call okay. At other times the calls go through without any issue.

There is no consistency to this at all. Dialling exactly the same number will work sometimes but not others with no changes made at all to asterisk in the interim and with obvious pattern as to why.

The same thing happens on both lines and it makes no difference if we initiate the calls from sip/iax2/asterisk console they all do the same thing. Dialling fails on local and national numbers. We have swapped TDM400 boards and modules and get the same every time.

/etc/dahdi/system.conf

[code]loadzone=uk
defaultzone=uk

fxsks=1
txgain=14
echocanceller=mg2,1
loadzone=uk
defaultzone=uk

fxsks=2
txgain=14
echocanceller=mg2,2
loadzone=uk
defaultzone=uk

fxsks=3
txgain=14
echocanceller=mg2,3

loadzone=uk
defaultzone=uk[/code]

/etc/asterisk/dahdi-channels.conf

[code]; Dahdi Channels Configurations (chan_dahdi.conf)
; Span 1: WCTDM/4 “Wildcard TDM400P REV I Board 5” (MASTER)
;;; line="1 WCTDM/4/0 FXSKS (In use) (SWEC: MG2)"
signalling=fxs_ks
callerid=asreceived
txgain=15
echocancel=yes
echocancelwhenbridged=no
delaxdtmf=yes
callwaiting=no
group=1
context=from-pstn
channel => 1

callerid=
group=
context=default

;;; line="2 WCTDM/4/1 FXSKS (In use) (SWEC: MG2)"
signalling=fxs_ks
callerid=asreceived
txgain=15
echocancel=yes
echocancelwhenbridged=no
delaxdtmf=yes
callwaiting=no
group=1
context=from-pstn
channel => 2

callerid=
group=
context=default

;;; line="3 WCTDM/4/2 FXSKS (In use) (SWEC: MG2)"
signalling=fxs_ks
callerid=asreceived
echocancel=yes
echocancelwhenbridged=no
delaxdtmf=yes
callwaiting=no
txgain=15
group=2
context=from-pstn
channel => 3

callerid=
group=
context=default[/code]

Extract from /etc/asterisk/extensions.conf

[trunknational] ; ; Long distance context accessed through trunk ; exten => _9X.,1,Dial(DAHDI/r2/${EXTEN:1},,TK) exten => _X.,1,Dial(DAHDI/r1/${EXTEN:0},,TK)

The rule for the 9 prefix is just there to force a call out on the other group for testing

# uname -a Linux pbx3 2.6.37.1-1.2-default #1 SMP 2011-02-21 10:34:10 +0100 i686 i686 i386 GNU/Linux

We use asterisk 1.8.3.2, and dahdi-linux-complete-2.4.1.2+2.4.1.

Any thoughts appreciated.

Cheers - Colin

Hi try

exten => _9X.,1,Dial(DAHDI/r2/w${EXTEN:1},TK)
exten => _X.,1,Dial(DAHDI/r1/w${EXTEN:0},TK)

this will add a dely in the dialing and allow the exchange to be ready,

Ian

I tried to add in the delay as suggested but that doesn’t appear to have helped we still get the unrecognised number error. It takes a fair delay before we get the error suggesting that insufficient digits are received by BT, and I would guess they are missing from the end when dialling. If they were missing at the start of the number the BT exchange rejects the call almost immediately as the number is already known to be invalid.