[Asterisk-Users] EC needed in all-digital situation?

[Mike Fedyk]

Eric "ManxPower" Wieling wrote:
> Warren wrote:
>> I was just told that for my forthcoming system I will be getting a data
>> T-1 instead of a voice T-1.  Given that all of the handsets will be voip
>> phones, no analog at all, do I need echo cancellation?  I looked at the
>> voip-info wiki and it seems to me that the answer should be "no" but I
>> would like to confirm that.
>
> If you never make calls to analog phones or receive calls from analog 
> phones, then you will never have echo.
>
> Can you be sure that all telephones you call out there on the world 
> PSTN will always be digital?  I didn't think so.
If you have no TDM equipment, then it is your provider's responsibility 
to handle any echo that may be generated if a call is routed through the 
PSTN.

There is more than one way for echo to naturally occur that have nothing 
to do with TDM circuits, like bad acoustics in a room as mentioned by 
another poster.

VoIP moves much of the quality needs from the center of the network to 
the edges.  That is, phones and gateways.