We've just switch from an Asterisk based PABX to 3CX, and now our SIP trunk works fine, but the TDM 800 card we had before for linking to our PSTN lines doesn't work. We hardly use the PSTN lines, but I'd prefer to have it linked into the PABX in case the SIP trunk/ADSL goes down, so we don't have to sit in the server room to answer/make calls, or have long wires draped around the office... So, is there any one or two port FXO adapter that anyone would recommend in particular (or not recommend) to work with 3CX. Preferably not too expensive. I've been looking at the Grandstream Handytone 503 or the Linksys SPA3102 - are those any good?