How can I monitor network usage by process on Mac OS X? [duplicate]

Solution 1:

Mac OS X Lion (10.7.x) contains a command called nettop that gets you most of the way there. Be sure to check the man page to learn the navigation keys and note the d key for toggling delta display. Not quite the kB/s display you were looking for, but close perhaps.

I'd be interested in hearing if this works better or worse for you than your iftop/awk/lsof hack.

Update: Also, be sure to make your terminal window...
R       E       A       L       L       Y       W       I       D       E.
nettop has lots of columns that it won't draw and won't even tell you about if your terminal window is too narrow.