[asterisk-users] Audiocodes MP-114 noise

Wed Nov 8 01:25:21 MST 2006

Jessee,

Thank you for your help.
I downloaded firmware and sample configuration files.
But the firmware was old version for MP118 and MP124.
Where can i download recent one?
Can i upload only ini file to change
countrycoefficient ?

Regards,
Jason.

--- Jessee J Holmes <jholmes at atacomm.com> wrote:

> Jason,
> 
> First, before you start reading, get to the latest
> firmware from  
> Audiocodes (MP118_SIP_F4.80A.034.004.cmp), there
> have been  
> significant echo improvements in this version.
> 
> After many days of working with Audiocodes on this
> problem and much  
> time spent here by multiple technicians trying to
> reproduce and  
> resolve this issue; this morning, Atacomm received
> an email from  
> Audiocodes with a full explanation to this now
> confirmed issue with  
> all MP-11x units. Atacomm will immediately begin
> work on a KB article  
> within our website that confirms this issue and
> outlines the  
> manufacturer recommended steps to resolve this
> problem.
> 
> Apparently, there have been some changes with the
> MP-11x's that can  
> negatively affect line noise and echo.  Below are
> some steps which  
> can help to correct these problems:
> 
> 1. The new design did away with the Coefficent file.
>  Audiocodes, now  
> instead, introduced a configurable parameter called 
> 
> countrycoefficient. This parameter can be adjusted
> to a specific  
> country based on known configurations.  For the most
> part this should  
> work.  70(USA) is the default value.  More can be
> found in the User’s  
> manual.
> 
> 2.  In just about every case, an FXO is added to a
> Pre-existing PBX  
> or CO line, you can expect echo. This comes from the
> fact that delay  
> (IP Network) is being introduced, and what used to
> be Side tone is  
> now delayed so much it is echo. Just about every
> difference on the  
> line that can be heard between the pre fxo and post
> fxo installation  
> can be traced to echo, or line quality issues.
> 
> 3.  Going forward, Audiocodes would like to suggest
> that when  
> installing the product do the following:
> 
> A) Make sure the Line coming from the PBX or CO is a
> Loop Start line.  
> Ground start is not supported on the MP-11x series
> of gateways. (The  
> M1K FXO will in 5.0)
> 
> B) Check that the Line can deliver for a 600 Ohm
> Impedance line
> 
> -52 to -24 V of Off Hook Voltage
> 
> -15 to -6 V of  On Hook Voltage
> 
> 20 to 35 ma of loop current.
> 
> If you know the line is not 600 Ohm, please gather
> metrics on the  
> line, and the make and model of the PBX or switch it
> is attached too,  
> plus country of origin. If it is not from the USA,
> please look up the  
> country of origin and then find the
> CountryCoefficient to match this.  
> Load the .ini file to the board with this setting
> and reset.  Make  
> sure the Gateway has a firmware version of 4.60.035
> or higher or  
> 4.80.030 or higher.
> 
> C) Put the device on the network with Voice Volume
> set to 0 and input  
> gain set to 0. Make calls, if there is no issue, you
> can stop here.   
> However, Echo is still expected most of the time.
> 
> D) The echo should be heard by the IP side
> participant as their voice  
> is reflected back.  If this is the case, then what
> needs to be done  
> is to lower the voicevolume (IP—TEL). This way the
> speaker’s  
> reflected voice will comeback low enough for the
> ECAN to cancel it  
> out (-6 is usually recommended as the value to plug
> in here). A  
> little experimentation is needed as the loss for all
> lines will vary  
> based on length from the CO. Echo is usually taken
> care of in this  
> manner.
> 
> E) The incoming speaker from the PSTN’s voice seems
> low, set  
> InputGainLocation =1, and then slowly increment the
> Input Gain  
> Parameter(Tel?P) to adjust for this. In past
> releases (see the note  
> about loads above), the input gain was always
> applied prior to the  
> ECAN which had the effect of amplifying the returned
> echo and noise  
> on the line causing crosstalk and clipping issues.
> This is no longer  
> the case.
> 
> If the above does not resolve the issues, then you
> need to go ahead  
> and collect DSP, Ethereal and Syslog traces along
> with the board.ini,  
> these are to be sent to your support agent, who will
> then send these  
> to Audiocodes for their engineers to evaluate.  This
> should not  
> happen often.
> 
> 
> Jessee Holmes
> Atacomm / Ataractic Corporation
> www.atacomm.com
> V: 1-877-700-VOIP
> jholmes at atacomm.com
> 
> Looking for voice over IP products?  Visit our VoIP
> store at http:// 
> voipstore.atacomm.com/
> 
> On Nov 3, 2006, at 12:14 AM, Jason Kim wrote:
> Jessee,
> I tried many combinations of "Voice Volume", "Input
> Gain" and packetization time , but it's noisy steel.
> I'm using G.711A-law and packetization time is 20ms.
> It can be impedance mismatch problem but i cannot
> adjust impedance of FXO port of MP-114.>
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