graphviz - how to create a 'roundtrip' flow

Question

I\'m trying to create a \'round trip\' graph using the graphviz. Given the result below, my objective is to have the PINK squares between the NET and the COM (note from the pict

Answer 1

If you simply reverse the direction of the edges going back (dir=back) by changing the line

NET -> fn2 -> rbd2 -> ddate2 -> fare2 -> COM;

into

edge[dir=back];
COM -> fare2 -> ddate2 -> rbd2 -> fn2 -> NET;

you should get: