>Our company has 3 remote sites that want to backup 26G+/- per day.  Our
>network is not prepared to handle this at present date.  I am exploring
>installing single 3590s on RS6000 at each site.

Your company has to get realistic.  Upgrading your network to modern
standards has to be cheaper than deploying very expensive tape drives
to each site and investing $$$ of sysprog/sysadmin time to make it all
work...somehow.  (And are those sites really backing up 26GB per day,
or is that just the size of their file systems, of which only some part
would be subject to incremental backup?)  You need the network anyway,
so might as well go for that.  Also consider the implied aspect of the
situation: being able to rapidly restore those file systems.

A company of any size without decent networking is behind the times
these days.
                 Richard Sims, BU