I suggest a tall cat tree. He has his space and you have yours.

Bigger apt. Another cat.

I wonder if CJ feels as though you are taunting him. Maybe he could use some type of a distraction.

A scaled down version of this may work?

or a cat tree

Squirt bottle, filled with water

I am currently in the process of "catifying" my four-cat home. I have two tree dwellers and two ground dwellers. The issue is with one ground dweller attacking the others and the other ground dweller being attacked by the others.

The tree cats are an easy fix: provide trees, wall mounted shelves, etc...

Providing options for the ground dwellers is not so obvious. I am thinking to offer multiple types and locations of cat beds, along with placing some SLIGHTLY up off the floor.

I wonder if a similar approach might remove your feet from your cat's level, reducing the attacks.

Cats can be taught , what you expect of them . Consistency is the key . Each and every time , you walk past him and he attacks you , pretend you're the mother cat . Take a handful of the nap of his neck , in the same way that a mother cat would lift her kitten up , and hold him , so that his mouth and paws , can not reach you . I recommend that you practice when you do not have a phone call , so you have two hands if needed . Pretend you are on the phone and walk in the same manner . You are the Momma cat . He is the spoiled kitty .

Wear hip boots.

I'd say to take your calls outside, but that's not always ideal. Is there any room with a door that you can put him in while you are on the phone? If not, maybe discourage the behavior by squirting him with water when he does it.