[asterisk-bugs] [Asterisk 0016371]: Asterisk detects DTMF inband even when dtmfmode=rfc2833

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=16371 
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Reported By:                amorsen
Assigned To:                
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Project:                    Asterisk
Issue ID:                   16371
Category:                   Channels/chan_sip/CodecHandling
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     feedback
Asterisk Version:           1.6.0.19 
JIRA:                        
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2009-12-02 06:28 CST
Last Modified:              2010-01-06 04:57 CST
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Summary:                    Asterisk detects DTMF inband even when
dtmfmode=rfc2833
Description: 
When Asterisk has a peer with dtmfmode=rfc2833, it should not react to
inband DTMF. Unfortunately, it does.

The problem happens when using the Dial option t to allow the callee (B)
to transfer the call. When that is done, Asterisk starts interpreting DTMF
in order to detect the transfer button presses. At the same time, Asterisk
strangely turns into an inband-to-rfc2833 gateway, even though both caller
(A) and callee (B) are speaking rfc2833. When the CALLER (A) noises
resembling DTMF, those get translated to rfc2833 DTMF, which can be quite
annoying especially when the noises weren't DTMF in the first place. I have
a tcpdump showing no rfc2833 frames coming from the caller but rfc2833
being sent to the callee (B).

Asterisk 1.6.0.18.

Reproduce by setting up two SIP phones with dtmfmode=rfc2833, call from
one to the other and make sure that Dial has options tT. Then play
DTMF-like noises through one of them. Dump packets going to the other phone
and notice how no rfc2833-frames are sent from the phone to Asterisk, but
rfc2833-frames are sent to the other phone.
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 (0116110) amorsen (reporter) - 2010-01-06 04:57
 https://issues.asterisk.org/view.php?id=16371#c116110 
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With relaxdtmf=no the problem is gone as far as Asterisk is concerned.
Sorry for the inconvenience.

We still have the problem, but that is because one of our providers
mistakenly generates DTMF. It took a long time to prove that the tones came
from our provider unfortunately.

This bug can be closed unless someone feels that Asterisk shouldn't try to
turn inband DTMF into RFC2833 DTMF when relaxdtmf=yes. I don't really care
much either way; relaxdtmf=no does not cause me any trouble. 

Issue History 
Date Modified    Username       Field                    Change               
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2010-01-06 04:57 amorsen        Note Added: 0116110                          
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