Somewhat off topic, but I must confess I just love my new Cisco SPA525G ! When we started with 3CX, I used a Grandstream GXP2000, then advanced to an Aastra 55i. Now, the Cisco is light years ahead of them all. Very nice feature set, easy configuration, etc. etc. Anyone on the fence about the phone, I can attest to it working great on 3CX v8. We have them throughout the office on WiFi, and here on my desk it's wired. All are going through the SIP Proxy (tunnel), but we've run them just as well with STUN servers.