spa3102 echo problem with PSTN

Discussion in '3CX Phone System - General' started by jits04, Jul 21, 2007.

  1. jits04

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    Hi,

    this time I need help. I have some problem with this voip gateway. Call placed with voip provider are ok (no echo). The problem is on PSTN line.
    When I call I have a terrible echo of my voice. The other end is ok. I have tried a lot of settings without good results. Can someone that is using it without problem send me the configuration. Just save as complete html page.

    You use other voip gateway and you haven't echo problem. Please, tell me the brand and model.

    Many thanks in advance

    William
     
  2. RobLloyd

    RobLloyd Member

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    I had the same problems with the SPA-9000 and SPA-400 using 4 analog lines. I'm going to the the Grandstream GXW-4104.

    I'm just testing 3CX for a few more days before ordering it. I'll let you know the results when I get it.

    Rob Lloyd
     
  3. Cjay

    Cjay New Member

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    Is the echo cancellation enabled in the SPA3102 PSTN Line, Audio Configuration section? Might also be worth looking at the PSTN line impedance - log in as advanced, then under PSTN line, International Control, FXO Port Impedance what setting do you have? Here in the UK 370+620||310nF seems to work fine with no echo. The nominal line impedances vary by country, but no harm in playing around with this.

    HTH!
    Chris.
     
  4. Anonymous

    Anonymous Guest

    A typical attempt at a fix involves:

    1) Ensure your ATA/Device is using the correct line impedance setting
    Page 182 and 530 (not sure what it is for UK or Ireland)

    2) lower your ATA's output volume/gain - ie the volume of the sound you hear on your phone to a point where the call is just loud enough for you to be happy with the call.
    Page 531 (for what ever it is set decrease it by 3 at the time, you can even set it to 0)

    3) If echo persists, lower your microphone sensitivity such that the person on the other end of the phone can still hear you comfortably.
    This is on your phone.
     
  5. jits04

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    Hi itfarmer,

    I live in Italy. Correct line impedance should be 270+250||150nF. I have try to adjust SPA TO PSTN Gain, but I still hear my voice when I speak
    ( for the person on the other end of the phone there is no problem. He can hear me comfortably ).
    The spa3102 add 30ms of latency to call during converting from analogic to voip and then from voip to analogic. I setup up Jitter level to low too. This should decrease this delay across spa3102. But It doesn't work. Eco level is about the same.

    Some extra suggests?

    Regards

    William
     
  6. Anonymous

    Anonymous Guest

    William,

    Are you using a softphone or IP phone.

    If the called party is ok, than it might just be that your phone on your desk has the volume of the mic to high, try to reduce that.

    Try this.

    PSTN line, international control

    SPA to PSTN Gain: 0
    PSTN to SPA Gain: 6


    Regional --> Miscellaneous

    FXS port Input gain: -3
    FXS port output gain: -3

    Make sure you DTMF playback still works after that.
     
  7. jits04

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    Dear all,

    1) I think that configuration is ok. I have tried to change the parameters as itfarmer told, but I still have the echo.

    2) I use last firmware. I have check with Cjay configuration too. Config are about the same. Italian settings are different

    3) I have change the spa3102 box with onother. Same result.

    4) I tried with 3phone (1 Hardware IPPhone, 1 old phone connect to spa3102 and I have tried with cordless too). I have tried to reduce speaker volume on Hardware Ipphone. I have still echo.

    Tomorrow I think to try it in another place. My old phone were connect with parallel method. But I don't think that it could be a problem.

    William
     
  8. Anonymous

    Anonymous Guest

    these settings are only the start, keep lowering them (-3 at the time) untill the echo goes away or you are unable to have a conversation.
     
  9. jits04

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    Ok, I try in another office. I have echo. Less, but I have it

    My line voltage is -36(V). Should it be +36(V)?

    But I don't think this is the problem.

    Ok, itfarmer. I have tried to reduce them without results. If I don't use FXS I think that I don't need to chenage Regional setting. I'm using and IPhone. In this case I should decrease PSTN to SPA gain. 3,0,-3,-6. There is no different!

    Extra suggests?

    Should I try to by another model?

    thanks again
     
  10. jits04

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    Hi itfamer,

    I'm go crazing, but now it's going better.

    My setup are for PSTN:

    SPA To PSTN Gain: 0
    PSTN To SPA Gain: -10

    to increase the called party voice should I increase SPA to PSTN?

    Many many thanks

    William
     
  11. Anonymous

    Anonymous Guest

    Yep, you can do that or increase the volume on your phone.

    See VoIP is not like bang put it on and it will be fine. you can tune each device in the chain to do what you want.

    Eg. if your voice on your internal network is low, crank up the volume on the pone. If there is low volume going out crank up SPA to PSTN but if you crank both up you end up with echo etc.

    Interesting you mentioned that, not sure where you are in the world. but the voltage should be + so you got a polarity issue (twisted wires, like black goes on red and red goes on black) Try to get it to + instead of - and you might find some problems disappear.
     
  12. pkothe

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    Echo Problems continue

    I have deployed my first system and it is not going well. The system is out in the country and the phone lines are plain junk. They vary a ton between the lines. One is so faint that I have set the DB gain to 31 and it is still faint. I am using an Audiocodes 8 port box and the only way I can get teh echo down is to make a profile for each line and apply a different setting to each line. I worked with the customer for hours testing and tweaking from multiple networks eg. cellphone, landline, my voip system. All three systems had a different echo problem also the echo would be gone in the beginning of the call and creep in during the call and then it might go away or stay there. We had all of the inbound calls on each line with no echo and the next morning it rained and we had echo. I am ready to jump off a building and Audiocodes is very hard to get on the line. I tried the Grandstream in my office and I still have echo. It does not bother me that much but these people are ready to kill if they hear the slightest echo. Has anyone ever made all of the echo go away? By the time I get the echo gone you are not able to hear the person or they can't hear you. I am using the Linksys 962 phone and my gain is set to -6 on the phones to reduce the echo. I wish I could go to a T1 then I would have no echo because I would have no AD conversion. Any light on the subject would be great.

    Thanks,

    Paul
     

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