David Floyd wrote:
[color=blue]
> For over two years now I've been using an SPA3000 with voip.co.uk with
> no problem.
>
> I have not used BT during this time, but now that free calls are
> available evening and week-ends with BT, whereas they are still 1ppm
> with voip.co.uk I have set up the SPA so that I can make calls via BT
> when I need to.
>
> The trouble is I cannot get the quality right.
>
> Apparently the person I call hears me fine and I can hear them OK, but I
> get an echo form my own voice and sometimes a bit of breaking up when
> both parties cross talk.
>
> I won't list all my settings here at this point (far too many) but if
> any-one has any ideas to correct this and wants to know particular
> settings that I already have, I'll list whatever you request.
>
> I cannot understand why the quality should be affected when it's not a
> voip call :-(
>
> Hope some-one can help.
>
> David[/color]

I've been round and round on this one with the SPA3102. The basic problem is
a stupid design. Using VOIP internally between the FXS and FXO ports is
unnecessary and the resulting delay makes echoes a problem.

There is loads of advice on-line about tweaking gains, etc. but I never
found that this helped significantly. In the end, I just tried the three
echo cancellation/suppression settings on the PSTN tab to find the least
objectionable combination:

Echo canc enable needs to be on.

Turning Echo canc adapt enable on works great most of the time but it fails
horribly when both ends speak at once. Then there are really loud and
disconcerting bursts of echo. Keep this one off.

Then there is a tradeoff with Echo supp enable. If it's off, the echo is
annoying. If it's on, you won't hear the other end if you both speak at
once. On balance, I've resorted to having it on and get relatively few
complaints.

The SPA3102 is a great device except for two big flaws: far too many
settings and awful echo problems. They should have consulted someone who
knew something about telephony when they were designing it.

Steve

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