Of course it is about respect - he is disrupting the class. You need to find out why he is doing this repeatedly.
Is he not being engaged? Does he dislike the subject? What can he do to become more involved in the class? Is it bad influence and peer pressure from other disruptive friends in the same class? Is he not picking up the coursework and feeling incompetant so acting out to cover it?
These are things you can work on with the school , his teachers and his year level coordinator, but you will need to be proactive and get involved - and he will need to know you are involved.
At one point my mum threatened to come and sit in on every one of my brother history calsses when he was 16 - hewas mortified, funnily enough he found a way to behave in class pretty quick smart. (And it wasn't a threat - she would have done it, she was like that)

Once you get to being 14, 15, 16 years old, the onus of 'learning discipline' moves somewhat from what hte teachers can teach you to what the student is will ing to learn and take on board. This usually relies on things like exclusion, for the reasons I mentioned above, but he needs to value the learning to begin with - this is where you come in.
He KNOWS what behaviour is expected, he knows that he will be excluded from the class (or moved to the front, or kept behind, or called on more often to answer questions) if he does not comply to the expectations of class - he is choosing not to obey them anyway.
What discipline would you like them to use? What expectation do you have of the principal if he was to be sent there everytime he was playing up? Why do you think the principal's words will have any more effect than the class teacher?

If you are going to talk with the school about htis, they will ask you these questions, and they are things you will need to work out before you go in - what are your expectations? What methods would you expect them to use?