Biting back = BAD IDEA
This is typical behavior for his age, he has figured out that he has teeth, and wow, look what they can do!!!
Be consistent with him. When DS bites you, say "Mama doesn't like it when you bite" and then set him down and walk away from him. Separating yourself from him when he does it will show him that you mean business (You don't have to put him in time out or anything, just distance yourself and "ignore" him for 30 seconds to a minute or so) It really isn't even necessary to raise your voice to him, just be firm, but gentle.
He will outgrow rather soon this as long as you are consistent with your actions.
Hope this helps a bit!