I think it is not a gain problem because I have echo. I've spent a lot of time trying make it dissapear but it was impossible. I have a lot of doubs about how SPA3102 treats one call:
- How can I know if a echo problem in a call from FXS to FXO (or FXO to FXS) refers to FXS gain or FXO gain config value?
- How exactly FXS input gain affects one of those calls?
- How exactly FXS output gain affects one of those calls?
- How exactly SPA to PSTN gain affects one of those calls?
- How exactly PSTN to SPA gain affects one of those calls?
- Could FXO and/or FXS impedance have any influence on echo?
- Which would be good values of impedance for Spanish telcos? Is there any way to know which is the best value to use?
- Regarding SPA echo cancel capabilities, What is the differente between Echo Canc Enable, Echo Canc Adapt Enable and Echo Supp Enable? How the affect to echo cancel of SPA? If I set to yes those three values I cannot send faxes correctly.
Is there any guidelines to follow when echo appears? Is there any tech document explaining all these config values fully explained?
Sorry for asking so many questions but I've trying to make work SPA for hours without success.
UPDATE:
Tested also with a SIP to PSTN call having the same echo problem. Configuring SPA with another PSTN line from another telco I get the same result. Always I hear my voice echoed...
