[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)
Reproducibility:            have not tried
Severity:                   feature
Priority:                   normal
Status:                     confirmed
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Date Submitted:             2008-09-26 04:27 CDT
Last Modified:              2009-06-04 10:55 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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 (0105991) sruffell (administrator) - 2009-06-04 10:55
 https://issues.asterisk.org/view.php?id=13562#c105991 
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biohumanoid: I'm convinced.  But, I'm wondering instead of adding the
echocan_hpf_tx member, that instead echocan_process should be changed to
echocan_process_tx and echocan_process_rx then dahdi_monitor could really
have something to process for the pre/post streams on tx.  (unless of
course that was always intended to *really* do some echocan by subtracting
the received signal from the tx signal.  But that isn't my experience) 

Issue History 
Date Modified    Username       Field                    Change               
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2009-06-04 10:55 sruffell       Note Added: 0105991                          
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