I read in the Bittorrent protocol that Bittorrent sends keep-alive packets of length=0 occasionally (around every two minutes) to maintain connections. I'm trying to identify these packets, so I captured all my network traffic while using uTorrent.
When I look at the packets, I see a lot of TCP packets with length=0, but they seem to be ACK packets sent in response to receiving downloaded data. Does uTorrent use keep-alive packets? If they do, how do I identify them?