Echo: nothing should be this much trouble (need advice pls)

Hello. Thanks for reading my post.

I’ve been using asterisk 1.2.x for the last year or so to handle my incoming calls at home. It would be tough to go back to life without asterisk. Unfortunately, I’m stuck with trying to tie in a PSTN line. Getting rid of the PSTN is not really an option since I depend on it for DSL.

I started off with a Linksys SPA-3102 but have put up with terrible echo problems from the start. I’ve gone through all the settings I can find, read all the posts, tweaked the gains, played with the echo cancellation settings, tried all the various impedance values but nothing gets rid of the echo, especially when both parties speak at the same time. This has a pretty low wife acceptance factor.

I also have access to an x100p but have had lots of echo with that too, plus it misses the callerid sometimes. I’ve only tried the mark2 canceller so far but the echo is still pretty bad with it. I plan to try the oslec canceller when I get time.

I’ve eliminated my in-house wiring as the source of my echo by disconnecting the house and plugging straight into the box outside.

So I need some advice. Will plunking down the money for a TDM400-based card help? Would a card with hardware-based echo cancellation help? Is there some other option out there that I haven’t thought of?

I live in North Alabama (not too far from Digium’s home in Huntsville) and my telco is Bellsouth (now AT&T). I am apparently on a pretty long loop which may be the cause of some of my echo problems. I’m using zaptel-1.2.23 and asterisk on a Gentoo system.

Thanks for any help you can give.

mr. echo


I personally have no experience with the SPA3102, but I have used the x100p and have had mixed results. It worked great at one location, and terrible at another, so I ended up replacing it with a TDM400P (that card does not have hardware echo cancellation).
I tried all the different echo cancelers and got it down to a reasonable level where it was barely noticeable. I needed to use fxotune to get all the levels set correctly.

Then one day I tried the oslec canceler and wow, it got rid of echo I didn’t know I still had. It really makes a difference.

First I would start with a good card, the TDM. Then set all the gains to 0 and use fxotune, and if that doesn’t do it, then add oslec and turn it on.

I just got a successful build of zaptel-1.2.22 with OSLEC on my Gentoo box. Maybe I can try it out later today.

Do you have any problems with your X100P getting caller id info? Mine is one of those “special edition” cards from and is supposed to have some kind of “improved caller id signal circuit”. It still seems to miss the callerid once in a while.

I don’t actually subscribe to caller ID, I use asterisk in a business and we don’t see it necessary.


You’re welcome to give HPEC a go if you like. All in-warranty analog customers get a license, gratis, for their card simply by contacting our Sales department ( and registering their card with us.