First off SIP needs less administration. Its a standard protocol supported by many devices and firewalls. Most public places allow SIP protocol to pass through thier firewalls. if your having issues at home get a real firewall/router. D-Link Gamer /wireless 1Gb router is the best bang for everthing. Passing encrypted packets on time is no easy thing for any router. Dich the junk Linksys/netgear routers and get a dlink. They dont buckle under voip calls. I have had zero issues with gizmoproject and its worth every penny. The only reason i want skype is because it makes the N800 more usefull to some people and that makes people build more application.