Rate is a swiss-army-knife command-line traffic analysis tool, designed
to help a network administrator to see what is happening at a router at
the moment. Unlike tcpdump(1), rate uses statistical and stream-oriented
methods, and will never produce an output stream at a speed beyond human
perception. The output is less accurate, however. Rate features four
different operating modes, designed to perform the following tasks:
estimating overall traffic rates, determining nodes generating the
highest traffic, determining connections and flows generating the highest
traffic and extracting strings from packets.