Ok... First of all start with your connection device. Is it a RAW modem or a combo (modem/router) unit? If it's a RAW modem then try connecting only your Xbox directly to the modem and be certain it's getting a public IP, not a 192.168 number. This will at least allow you to isolate your own stand alone router as a culprit if you maintain connection fine. If you have a combo unit (modem/router) you need to put it into bridged mode and go buy a decent router that supports UPNP and preferably DD-WRT firmware which you can google. I'd recommend Linksys/Cisco E1200 unit. if you can't afford a router or won't buy one, then unfortunately your at the whim of the crappy device combo your ISP gave you. The problem with using these devices is that typically they are running some modified version of firmware that either removes options, disables them or worse makes them irrelevant given that most use a script upon boot from your ISP to designate all the settings back to what they want them as. One other thing to check is that you disabled port scan detection and ip flood detection. Also do not use UPNP, DMZ, and port forwarding together. It's one or the other not all three. Also many routers prefer that you use DHCP rather than static with services like UPNP and port forwarding but be sure that you reserve a static IP through DHCP reservation tables (done by MAC address; this is also on the router usually in "advanced or routing section). This is a way of ensuring a static IP while maintaining transparency to the gateway through the DHCP server of the router. Many devices if given a static IP on said device will not be seen by the router in UPNP SERVIces. One final note be sure your home network is on IPv4 protocol unless you have some significant reason to use IPv6. It should work regardless but in my personal experiences I've run it to many anomalies with the tunneling from ipv4 to ipv6. If you personally want some assistance or have a question regarding networking the Xbox feel free to send me a message in Live!.