[c-nsp] Receiving faxes with Asterisk - strange problem

Bartosz Piec cisco at piec.info
Fri Feb 3 06:49:55 EST 2006


I'm trying to receive faxes with asterisk. My configuration is like this:

PSTN fax -> ISDN -> Cisco router with VoIP module -> Asterisk

When I try to send a fax from PSTN fax I got the standard fax signal, 
Asterisk starts rxfax application and then call ends and there is no tif 
anywhere. On the fax display there is still one message: Calling...
I think that it can be an issue with my Cisco router (2821).

This is part of my Cisco config:

voice-card 0
  no dspfarm
voice service voip
voice class codec 1
  codec preference 1 g711ulaw
  codec preference 2 g711alaw
  codec preference 3 g729r8 bytes 40
  codec preference 4 g723r63 bytes 96
  codec preference 5 g726r16 bytes 80
  codec preference 6 g726r24
  codec preference 7 g726r32
  codec preference 8 g728
  codec preference 9 gsmefr
  codec preference 10 gsmfr

voice vad-time 65536
voice translation-rule 1
  rule 1 /^0?/ //
voice translation-rule 2
  rule 2 /^1?2?/ //

voice translation-profile CutTwelve
  translate called 2
voice translation-profile CutZero
  translate calling 3
  translate called 1

voice-port 0/1/0:15
  echo-cancel coverage 32
  no comfort-noise
  music-threshold -70

dial-peer voice 1 pots
  translation-profile outgoing CutZero
  destination-pattern ^0
  port 0/1/0:15
dial-peer voice 2 voip
  description Route calls starting with 293 to centile
  translation-profile outgoing CutTwelve
  application session
  destination-pattern 1229339[60-79]
  voice-class codec 1
  session protocol sipv2
  session target ipv4:
  dtmf-relay rtp-nte h245-signal h245-alphanumeric
  retry invite 3
  retry response 3
  retry bye 3
  retry cancel 3
  timers trying 1000
  sip-server ipv4:asterisk.ip.add.ress

As I understand, the preferred codec is ulaw.
Should I change something in this configuration?
I tried fax protocol pass-through g711ulaw and g711alaw but this nothing 

I was searching for fax handling on Cisco site and I found something 
like this: 

I think that the method that suites my needs is "T.37 Store and Forward 
Fax" but it needs some TCL script that should be available on Cisco site 
but now they are gone 
(http://www.cisco.com/cgi-bin/tablebuild.pl/tclware). Does anybody know 
where to download these scripts from? Or maybe that isn't the best 
method for achieving this?

Best regards,
Bartosz Piec

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