To answer the question, yes it is possible. ANYTHING is possible first step is just removing the doubt from your mind. Cause nothing will be possible as long as you have a single doubt in your mind. I promise you if you 100% believed it was possible to connect you would.
I personally have done this, but only able to do it with one person, and that person was someone I cared for and loved dearly. Alot of the times she had to go to sleep on the phone with me, and I would stay on the phone. Maybe having a actual "connection" in this reality helps, not sure on that part, but what I do know is you have to have a "spiritual" connection with the person (atleast at first, maybe once you master it, can do it as you will, but baby steps are the key with learning anything).
Dont try to force yourself into the dream, just as if you were meditating let your mind go free, and just try to connect and be with them, and dont judge or try to force anything to see in your mind, and youll be amazed what happens.
Iam sure atleast one person will reply saying its impossible and iam wrong. But for anyone to claim its impossible and wrong would be claiming they know all, which I guarantee they do not. I speak from experience, take it or leave it, your choice just like life.