Within our present understanding, sure. I'm sceptical of there even been any other intelligent life to communicate with in the first place, since it's arguable that multicellular life arose on Earth as an accident rather than an inevitability. Still, assuming that hurdle to be crossed, there's no way that light-speed communication is plausible. As to anything beyond that... I wouldn't care to say. I think it's extremely unlikely, or at any rate whatever would be necessary is beyond my imagination. Faster-than-light communication would appear to break causality, so the only way around it is if there existed some sort of cosmic "short-cuts", connecting two points in space that would otherwise be too vastly separated to allow communication.
But the main point is that "impossible", or anything equivalent to it, is a dangerous word in science.