I am running XP on Dell desktop. Cable modem used is Motorola Surfboard SB5101 which is connected to a D-Link router EBR-2310 - a NAT box. When I make Skype video calls, the voice on both ends at times fades in and out or the call would just get disconnected. I understand that the problem could be on my end or on the other person's end. But I am wondering if there is a way for me to run sniffer (any shareware options?) to see what is going on? I also suspect that my ISP - Comcast - may be playing mischief. They used to when I used Vonage and I think Comcast paid some damages to Vonage for that one. How can I debug the problem? Any help would be great. Thanks.