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General Support => On-Topic: Obihai and OBi Products => Topic started by: Thunderbird1 on January 30, 2011, 11:51:59 PM

Title: Any Known Issues With Echo On PSTN Calls?
Post by: Thunderbird1 on January 30, 2011, 11:51:59 PM
Hi all,

I recently came across the OBi110 and I like what I see so far and am considering purchasing a unit or two.

I've been an avid user of the SPA units (still using a SPA-3000 with original firmware) but the one aspect of the SPA that took a lot of tweaking was the echo on PSTN calls due to the internal VoIP - PSTN leg being bridged as a SIP call.

My question is:
How is the VoIP - PSTN leg bridged within the OBi110? On a PSTN call or during fail-over is the bridging done using an internal SIP call or is a hard relay utilized?

Cheers,
-TB1
Title: Re: Any Known Issues With Echo On PSTN Calls?
Post by: obiliving on January 31, 2011, 01:28:59 PM
It's not using the relay; but it's not a SIP call either.
Audio will still go through device a/d and d/a with low latency.
I have not experienced any echo problem myself; and have not
heard other users mentioning it so far.

I had some experience SPA3000 and I understand
the type of echo problem you are talking about.
Title: Re: Any Known Issues With Echo On PSTN Calls?
Post by: MichiganTelephone on January 31, 2011, 02:48:55 PM
I'm probably not the best person to comment but I can say that I have noticed echo (and some strange noise artifacts) when using a SPA-3000 connected to the FXS port of a provider-supplied SPA-2000.  In that hookup I had to play with gain levels to get the echo down to an acceptable (barely audible) level.  In testing what is essentially the same type of setup here, I don't notice any of that.  Since there's a world of difference between that and a copper pair from a telephone company, all I will say is that it sounds better to me with that particular hookup, and let it go at that.
Title: Re: Any Known Issues With Echo On PSTN Calls?
Post by: Thunderbird1 on January 31, 2011, 08:20:07 PM
Thanks for the feedback guys.

Correct me if I'm wrong, my understanding of obiliving's post is that the bridging is done electonically using a/d & d/a circuitry which basically eliminates any potential for echo between the PSTN & FXS.