Seems much more robust than nfsen. Also, NTOP gives you all sorts of network statistics and lets you slice and dice flows both historically and in real time, all from a single Web console.

i am setting up new app/port monitoring.  i like nfsen because i can
zooom in and see who is sending all that port 43 tls between 11:42 and
12:19.  is there some other tool at which i should look?

randy