[Freeswitch-users] Linksys PAP2-T and echo

[Brian Hickey]

Hi Boris, what kind of analogue handsets do you have attached to the 
PAP2-T's? I have found with other ATA's (mostly Grandstreams) that it is 
the impedance settings for the handset that contributes the most to 
echo. Different handsets can be seup for different countries and 
sometimes you have to adjust the ATA to match.


Regards
Brian



On 01/11/2011 02:39, Boris Kovalenko wrote:
> Hello!
>
>       Steve, my configuration is:
>
> PAP2-T (A) ---- FreeSwitch --- PAP-2T (B)
> I tried Freeswitch in all modes: default, proxy_media, bypass_media. The
> echo is always present. User A hears its own echo, and user B hear its own.
>
>> Hi,
>>
>> The echo canceller in the SPA3102 is a disaster, but the ones in the
>> PAP2T and SPA2102 shouldn't give you problems. If you use the default
>> gains you shouldn't really notice echo. If you set some wild gains you
>> might bee poor results. Are you sure the echo originates from the PAP2T,
>> and not some other part of the signal chain?
>>
>> Steve
>>
>>
>> On 11/01/2011 12:42 AM, Boris Kovalenko wrote:
>>> Hello!
>>>
>>> Steve, Darcy, I've played ... no success :( Setting FXS to -15 do echo
>>> acceptable but I still can hear it. So there is no way to eleminate echo
>>> with Linksys devices? Only to buy more professional devices like Addpac?
>>>> on your pap2t web interface, go to voice, advanced, select the line, the
>>>> settings below will allow you to play with echo cancellation.  However, you
>>>> also need to go the the regional tab in voice and play with the fxs input
>>>> and output gains, the voice gain on the pap2t or any linksys gateway, will
>>>> impact the echo on the line.  This is most likely where your problem is.
>>>> You might not be able to cure the echo on every call, but you should be able
>>>> to make it acceptable.
>>>>
>>>> Darcy
>>>>
>>>>
>>>> Audio Configuration
>>>> Preferred Codec:        Second Preferred Codec:
>>>> Third Preferred Codec:        Use Pref Codec Only:
>>>> Silence Supp Enable:        Silence Threshold:
>>>> G729a Enable:        Echo Canc Enable:
>>>> G723 Enable:        Echo Canc Adapt Enable:
>>>> G726-16 Enable:        Echo Supp Enable:
>>>> G726-24 Enable:        FAX CED Detect Enable:
>>>> G726-32 Enable:        FAX CNG Detect Enable:
>>>> G726-40 Enable:        FAX Passthru Codec:
>>>> DTMF Process INFO:        FAX Codec Symmetric:
>>>> DTMF Process AVT:        FAX Passthru Method:
>>>> DTMF Tx Method:        DTMF Tx Mode:
>>>> DTMF Tx Strict Hold Off Time:        FAX Process NSE:
>>>> Hook Flash Tx Method:        FAX Disable ECAN:
>>>> Release Unused Codec:        FAX Enable T38:
>>>> FAX T38 Redundancy:        FAX Tone Detect Mode:
>>>>
>>>> -----Original Message-----
>>>> From: Steve Underwood
>>>> Sent: Monday, October 31, 2011 11:11 AM
>>>> To: FreeSWITCH Users Help
>>>> Subject: Re: [Freeswitch-users] Linksys PAP2-T and echo
>>>>
>>>> On 10/31/2011 10:58 PM, Boris Kovalenko wrote:
>>>>> Hello!
>>>>>
>>>>>
>>>>>           I'm wondering if it is possible to solve echo with Linksys PAP2-T
>>>>> devices. Does anybody here uses it? I read many articles and still can't
>>>>> understand how to eleminate echo :( I read
>>>>> http://www.voip-info.org/wiki/view/Asterisk+echo+cancellation and found
>>>>> that Asterisk has its own EC. Does Freeswitch has it too? I found this
>>>>> article http://docs.freeswitch.org/echo_can_page.html but can't
>>>>> understand - has Freeswitch EC or not? If yes - how to turn it on and off?
>>>> Neither Asterisk or Freeswitch will echo cancel your PAP2T. Echo
>>>> cancellation over IP is very problematic, and hardly ever attempted. The
>>>> PAP2T should be echo cancelling for itself, and they usually do a fairly
>>>> good job of this. I don't think it is configurable. Its always on.
>>>>
>>>> Steve