I have used vonage over my comcast cable connection since July of 2005 without a problem, until last week. the rumor on the vonage-forum is, since comcast is now rolling out their own telephone service, they are blocking all vonage and other voip networks. I do not know if it is true or not, but I have had spotty performance every since Friday, and all other internet access is fine. testmyvoip.net works great, and tracert.exe works well everywhere except to vonage. I can access the vonage web page normally only if I leave the comcast system, i.e. go to a coffee house with wifi. pings to the vonage web site are dropped, and log in can take minutes instead of seconds. vonage is posting on their web site that there are technical problems due to a comcast upgrade. I do not know if the problem is a vonage or comcast problem, but i will b e cancelling both of them soon if they don't get it straightened out.