[asterisk-users] Echo problem in VoIP-calls

[Gareth Blades]

Thats the jitter buffer. It has no effect on echo.

So you get echo when calling from the softphone to the analogue phone?
What about when one of those calls somewhere else?
What if they call a regular telephone number?
How do you connect in order to send calls to normal phone numbers?

Jonas Kellens wrote:
> Hello,
> 
> I stated in my first post that both ends hear an echo when one speaks to 
> the other...
> 
> The only place where echo cancellation is being applied is in the 
> Asterisk server. I have the following in sip.conf :
> 
> 
> ;------------------------------ JITTER BUFFER CONFIGURATION 
> --------------------------
> jbenable = yes              ; Enables the use of a jitterbuffer on the 
> receiving side of a
>                               ; SIP channel. Defaults to "no". An 
> enabled jitterbuffer will
>                               ; be used only if the sending side can 
> create and the receiving
>                               ; side can not accept jitter. The SIP 
> channel can accept jitter,
>                               ; thus a jitterbuffer on the receive SIP 
> side will be used only
>                               ; if it is forced and enabled.
> 
> jbforce = no                ; Forces the use of a jitterbuffer on the 
> receive side of a SIP
>                               ; channel. Defaults to "no".
> ;-----------------------------------------------------------------------------------
> 
> 
> Thank you for your replies.
> 
> Kind regards.
> Jonas.
> 
> 
> On 06/30/2010 11:36 AM, Gareth Blades wrote:
>> Routers wont cause echo. In order for them to do so they would have to 
>> store the outbound voice traffic, delay it and then mix it into the 
>> inbound voice.
>>
>> Telephones inherently cause echo. For domestic calls the audio path is 
>> normally so short that any echo arrives back so quick the human ear does 
>> not detect it. For international calls the telco uses expensive echo 
>> cancelation technology.
>> When you switch to voip you are often suddenly introducing a much larger 
>> delay so any excho which was present before but not noticed suddenly 
>> becomes noticable.
>>
>> You need to analyse the audio path your calls are taking, where the 
>> delays are being introduced and where echo cancelation is being applied.
>>
>> You also havent stated which end of the conversation is hearing the echo.