I'm only sure because I saw a bunch of RTMP and Flex messages going to the central servers (they all have similar IP addresses) and a lot of UDP traffic going t

I'm only sure because I saw a bunch of RTMP and Flex messages going to the central servers (they all have similar IP addresses) and a lot of UDP traffic going to a pretty much random IP address that changed with every person I talked to. Also, Fogbugz copilot does something similar. It's described at a high level here: https://www.copilot.com/tech/ https://www.copilot.com/tech/ which links to http://nutss.gforge.cis.cornell.edu/stunt.php http://nutss.gforge.cis.cornell.edu/stunt.php