"Martin Johnson" <user@example.net> wrote in message
news:EO-dnbNl5Ib85bjVnZ2dnUVZ_v7inZ2d@supernews.com...[color=blue]
> Christian wrote:[color=green][color=darkred]
>>> My SPA-3000 has never crashed, but echo cancellation has always been a
>>> bit poor (particularly at the remote caller's end), and dependent on
>>> audio gain levels set in the poorly-documented, over-complex web GUI.[/color]
>>
>> Martin,
>>
>> Maybe you tried this already, and maybe you're already tired of trying
>> stuff with the SPA-3000 already, but you might want to try different line
>> impedance configurations in the SPA-configuration, this does have an
>> effect on the echo canceller.
>>
>> Trying another analog phone also sometimes help, the local echo canceller
>> (which is the one that causes the echo at the remote site) sometimes
>> can't cope very well with specific (cheaper) phones, or a lot of phones
>> parallel.[/color]
>
> Thanks for the idea, I'll give it a go.
>
> In fact I have lots of different, vintage handsets running from the PABX,
> so I'm not making life easy for myself ;-)
>
>
> - Martin.[/color]

The correct impedance setting for UK telephones/pabx lines is:

370+620||310nF

best wishes - Steve.