Halo Co-op lag.

Now, I’m not exactly complaining, I love the game. However ever since Halo 2 co-op has always been laggy as hell if your in a game with someone with, well not bad connection but a slow connection. This is not aimed at Halo 4 but every Halo in general has had this problem and you’d have thought by name this lag would have been fixed but no.

I’d just like to know why for so long Halo has had this lag with co-op compared to other games that can work perfectly with co-op? I know it uses different serversd to matchmaking but surely they’d know why the games can be so slow for?