Echo issue

[zet]

Hi all,

I'm having an issue with echo when I make a call.
The thing is when I make a call to a mobile/ cell phone I don't have any echo, but the moment I dial or recieve a from a local number, I get echo issue, every time I talk I hear my self.
The client has a sip trunk and I contacted the sip provider over the issue and the told me that everything is ok on their end.
I wanted to know if the is an echo cancellation options in the pbx, because I don't see it.
I have a quadro m8l and yealink phones T-22 and T-28.

Also I wanted know if the issue isn't with my pbx or the sip trunk provider, could the issue be with my local phone company, who provides all the pstn services?

Krs,

[hrant]

Please explain the path of the calls having the echo issue and who hears the echo. For example,
a) IP phone >> Quadro >> SIP provider >> PSTN
b) IP phone user hears the echo.
As far as the echo cancellation is concerned then there is echo cancellation on Quadro, it is always enabled on telephony interfaces: FXS, FXO, ISDN BRI, E1/T1. For the calls going through Quadro between IP endpoints there is no echo cancellation on Quadro.

[zet]

Hi hrant,

The path of the calls is just like you described:

IP phone >> Quadro >> SIP provider >> PSTN, with the one using the ip phone hearing echo

and also vice versa when the Ip phone user recieves a call
PSTN-> SIP provider-> Quadtro-> Ip phone, with the Ip phone user hearing echo.

But receiving or dialing a mobile/ cell phone there is no echo

IP phone >> Quadro >> SIP provider >> mobile/ Cell phone, no echo and vice versa.

So the echo cancelation is always on.
But in which one of these interface categories of FXS, FXO, ISDN BRI, E1/T1, does the SIP connection fall for echo cancelation.

Krs,

Zet

[hrant]

Ok, thank you for details. The source of the echo in your case is the VoIP-PSTN gateway used by your SIP provider. It is the responsibility of the gateway to cancel the echo signal reflected from connection to telephony network. From IP phone up to gateway the voice goes over IP and neither IP phone nor PBX creates or cancels the echo. In case of cell phone there is no echo because voice goes IP/digital end to end (from IP phone to cell phone). If you cannot convince your SIP provider to fix the issue then you can try to reduce the Tx gain of IP phone. It may reduce or even remove the echo.

[zet]

Thx hrant, I've contact the provider and it was them that had the echo issue.

krs,

Zet