On which server run RMAN when duplicating database

I am reading the duplicate chapter of Robert Freeman's RMAN book.
If I copy the backup files from server A to server B as mentioned in the book, 
do I then run RMAN on server B.  If so, I understand that I will need a tns 
entry on server B back to the database on server A so RMAN can connect to the 
target.  Is this correct?

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