RTL worked by replacing the networking functions in a game, with our own custom written code.
The code is tweaked per game, and allowed RTL to react specifically to each scenario before the network stack was even involved.
This has some major benefits over just proxying the data, and is why RTL was more stable and worked better than other options.
Games with anti-cheat mechanisms often object to the way RTL operates internally.
Making it too difficult to add new titles to Reduce The Lag.