it keeps freezing

so every time i play with my friend one of us keeps freezing and getting timed out. its never both of us. we have has 1 normal play that lasted 30 minuets and then we try reseating we try waiting an entire day we try resetting our minecrafts and the same thing is still happening. we just keep getting booted or keep freezing every 3 seconds. not kidding i counted it and every 3 seconds it will freeze for 5 seconds. what do I do?!