Dear Sir Cedric and classmates (81515 lecture):

I am maximizing the use of this blog for my thoughts, not only on the assigned readings, but also on the lecture discussion =]

During the lecture, the idea of specific functionality that are implemented on the network layer vs those that are implemented on the application layer was given a little limelight (I remember we even have a slide dedicated to some practice exercise for this =] ). 

I just want to ask Sir, and fellow classmates, for a good example of a functionality that should be implemented on the network layer, a functionality that should be implemented on the application layer, and a functionality that can be implemented on either layers. 

Thanks =]

P.S.
will there be really a significant result if we try doing a functionality in a host, but it really is intended for the network?