this thing is cool!! look look    http://www.ex-parrot.com/pdw/iftop/

what’s all those columns in the  display of?  from the man page…

The  main part of the display lists, for each pair of hosts, the rate at which data has been sent and received over the preceding 2, 10 and 40 second intervals. Thedirection of data flow is indicated by arrows, <= and =>. For instance,
       foo.example.com  =>  bar.example.com      1Kb  500b   100b
                        <=                       2Mb    2Mb    2Mb