d3matt wrote:
I'm just installed our IPPBX2820 and also experienced terrible noise on the FXO port. I then was told about the grounding issue and to use the STP cable. Of course this only works if the switch you're connect to on the other end is a metal cased model with an earth connection in the mains plug. Many smaller switches don't.
So I've chopped the STP cable and wired the shield to the earth pin on a 3-pin mains plug, so the IPPBX is now earthed locally. It did make a difference, but it hasn't cured the problem. The main issue now is that everyone on the other end complains that were're too quiet. I've asked Draytek (SEG) tech support about to turn up the volume on the FXO port, but don't have an answer yet.
The other issue which has surprised me is that CLI doesn't work on the FXO port. This is a major issue and so much so that we've had to put the phones back onto the PSTN line and just using the IPPBX for the SIP trunk for now. Not good. I hope Draytek can issue a firmware fix for this.
Both these issues are important to me and I would need to know they've been resolved before I would part with any money.
There seems to be a general problem with these devices connecting the PSTN to VOIP, e.g. Linksys have the same problem with their SPA3102 and the higher the gain, the worse the echo, so you have to compromise and end up with it being a bit quiet with a bit of echo. Not ideal by any stretch of the imagination.
What's annoying is that it is obviously possible to do it right. My VOIP provider of course is doing exactly this, connecting the PSTN lines to their VOIP customers and the volume is just like an analogue phone with NO echo. So why can't Linksys and Draytek (and undoubtedly others) also get it right?
