This is not one of them. Frankly, unless you have a reason NOT to use TCP (and a very good one is realtime lossy communication), don't try to implement your own

This is not one of them. Frankly, unless you have a reason NOT to use TCP (and a very good one is realtime lossy communication), don't try to implement your own damn custom protocol on top of UDP that's just going to be a shittier TCP. This doesn't mean that TCP is perfect, but if you want lossless communication you will PROBABLY be happier there. If I'm writing a chess game, I could easily just stream the text format of the games over an IRC channel. Many things, including games, don't necessarily need high bandwidth or low latency over consistency. But the attitude is definitely not warranted.