Hmmm. That's not what I asked. I just want to know, if my BitComet's listening port is blocked, in which I can't be a server. How badly my download/upload speed will decrease ? Because in the Wiki of BitComet, it mentions that it will hugely impact the download speed. I just want to know how and why in a technical perspective. But I' think I've found the answer somewhere else. So thank you for replying :).