Average packet size (math)

[Ron Rivest]

Steve --

To make the argument clearer (since I received an inquiry
about it):

        (total work) = (setup cost per packet)*(total number of packets)
                       + (encryption cost per byte)(total number of bytes)

for any data stream.  Thus:

        (work/byte) = (setup cost per packet)*(total number of packets)/(total number 
of bytes)
                      + (encryption cost per byte)

                    = (setup cost per packet) / (average number of bytes per packet)
                      + (encryption cost per byte)

by which we see that it really is the *average* packet size that matters, not
the minimum, mode, or median...

        Cheers,
        Ron