[asterisk-bugs] [Asterisk 0018999]: rtpkeepalive blocks incoming DTMF periodically

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=18999 
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Reported By:                geejay
Assigned To:                
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Project:                    Asterisk
Issue ID:                   18999
Category:                   Core/RTP
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     new
Asterisk Version:           1.4.40 
JIRA:                        
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases):  1.4  
SVN Revision (number only!): 308580 
Request Review:              
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Date Submitted:             2011-03-19 06:21 CDT
Last Modified:              2011-03-25 23:34 CDT
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Summary:                    rtpkeepalive blocks incoming DTMF periodically
Description: 
When rtpkeepalive is not zero then comfort noise packets are sent
periodically. During sending of comfort noise packets incoming DTMF is not
processed.

These DMTF tones are lost.

The Function ast_rtp_sendcng in rtp.c mutes DTMF for a certain period
here:
rtp->dtmfmute = ast_tvadd(ast_tvnow(), ast_tv(0, 500000)); 

DMTF tones received during this period are not processed by Asterisk. 

I verified the problem in Asterisk 1.4.40. The code 1.6.2.17.1 seems to be
the same.
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 (0133122) geejay (reporter) - 2011-03-25 23:34
 https://issues.asterisk.org/view.php?id=18999#c133122 
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I dont see how this is a related to those Sonus issues. The problem I
describe here is much older.

The problem can be easily verified with a SIP trunk. Set rtpkeepalive=1 to
generate comfort noise packets every second. Then send a call from the
trunk to asterisk, answer the call and send DTMF RFC2833 packets to
asterisk. You will notice excessive lost DTMF tones. 

Issue History 
Date Modified    Username       Field                    Change               
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2011-03-25 23:34 geejay         Note Added: 0133122                          
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