[asterisk-bugs] [DAHDI-linux 0013562]: [patch] It's necessary to have high pass filter for tx signal of DAHDI.

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=13562 
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Reported By:                biohumanoid
Assigned To:                sruffell
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Project:                    DAHDI-linux
Issue ID:                   13562
Category:                   dahdi (the module)/NewFeature
Reproducibility:            have not tried
Severity:                   feature
Priority:                   normal
Status:                     confirmed
JIRA:                        
Reviewboard Link:            
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Date Submitted:             2008-09-26 04:27 CDT
Last Modified:              2010-10-20 07:23 CDT
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Summary:                    [patch] It's necessary to have high pass filter for
tx signal of DAHDI.
Description: 
It's necessary to have low frequency filter for tx signal of DAHDI. 
Otherwise, low-frequency signal from IP can reach a leased line, and
return back with nonlinear distortions. This will break an echo canceller.

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 (0128227) svnbot (reporter) - 2010-10-20 07:23
 https://issues.asterisk.org/view.php?id=13562#c128227 
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Repository: dahdi
Revision: 9442

U   linux/trunk/drivers/dahdi/dahdi-base.c
U   linux/trunk/include/dahdi/dahdi_config.h
U   linux/trunk/include/dahdi/kernel.h

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r9442 | sruffell | 2010-10-20 07:23:07 -0500 (Wed, 20 Oct 2010) | 18 lines

dahdi: Add compile time DAHDI_ECHOCAN_PROCESS_TX option.

Add optional interface to allow software echo cans to process the
transmitted samples.  Can be used for things like DC removal.

I used the following patches uploaded by biohumanoid but changed the
name of 'echocan_hpf_tx' to 'echoan_process_tx and put the changes
behind a compile time option.

(issue https://issues.asterisk.org/view.php?id=13562)
Reported by: biohumanoid
Patches:
      kernel.h.patch uploaded by biohumanoid (license 459)
      dahdi-base.c.https://issues.asterisk.org/view.php?id=2.patch uploaded by
biohumanoid (license 459)

Signed-off-by: Shaun Ruffell <sruffell at digium.com>
Acked-by: Kinsey Moore <kmoore at digium.com>
Acked-by: Russ Meyerriecks <rmeyerriecks at digium.com>
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http://svn.digium.com/view/dahdi?view=rev&revision=9442 

Issue History 
Date Modified    Username       Field                    Change               
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2010-10-20 07:23 svnbot         Note Added: 0128227                          
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