Richard,

I don't have experience with electronic vaulting.  But I do understand
reclamation.  The process is as follows.  The TSM polls all the volumes that
meet the threshold size.  The reclaimed volume goes active and a scratch volume
goes to a destination drive.    This process continues until all selected
reclaimed volumes have move their data to the scratch volumes.  I would think
that only the data that needs to update the TSM DB would transmit on the net.
That information would be the new volumes.  I hope that helps