[Asterisk-Users] Problem with fax tone (CNG) and fax detection

[Michael Welter]

Michael Welter wrote:
<snip>
> 
> Channel: Zap/g2/3036701917
> MaxRetries: 1000
> RetryTime: 60
> WaitTime: 45
> Application: TxFAX
> Data: <filename>.tiff|caller
> 
> Note: All calls are going to the same fax machine, so some attempts on 
> the second line will get a busy signal (there are two POTS lines in 
> group 2).
> 
<snip>
> 
> I'm using today's cvs and spandsp-pre6.
> 
<snip>
> 
> 

The problem with the call files is that the busy tone is not being 
detected, and the reason the busy tone is not detected is because the 
fax tone (CNG) is being injected onto the line by the TxFax application.

When I remove "|caller" from the call files (no CNG tones), all fax 
calls are properly sent (busy is detected by * and the call retried). 
However, by removing "|caller| and not sending the CNG tones, some fax 
receivers will not be able to properly handle the call.

Is there some way for * to detect busy tones while ignoring (filtering) 
the CNG tones?

Thanks,
Mike

-- 
Michael Welter
Introspect Telephony Corp.
Denver, Colorado US
+1.303.674.2575
mike at introspect.com
www.introspect.com