I am currently using a wirless broadband modem to connect to xbox live. I can connect and play games but can not join a party or invite friends into a game. I have an AT&T wifi device model 754s by sierra wireless. the modem has no UPnP option. I have enabled port fowarding and assigned the ports listed in your post to the internal IP of my gaming console. I have contacted the provider by email but have not gotten a reply yet. Do you have any suggestions? There is not any other type of broadband service available in my area.