UDP, on the other hand, may deliver A then B then C (which is what will happen when you're testing your game on your LAN) or it may deliver C then A then A then C (which might happen if you're in a low-bandwidth internet cafe). That's right; it could duplicate your traffic, put it out of order, and drop it. It makes no promises except a weak offer that probably the contents of C will be the same on one end of the wire and the other (and that it won't break up C into pieces).