the handshake - it's been suggested most recently by an notable SETI radio astronomer . the the communication might be one way do to the enormous distance involved to transmit signals and get an response w/ currant tech
know how. (time-distance)
how will this occur and when is speculative. it raises interesting
questions about alien protocol , (something we still are developing on earth).
once received. do we dumb down our technology or if in the realm of possibility improvise and improve native signals. example: that was definitely an message in a bottle . or, that signal was so stong it influenced our orbit.
what we say and how we do it. says a lot about us.