In today’s world of commercial Internet service, it is becoming
increasingly important to know
how much data you are transmitting and receiving on your network connections.
If you are an Internet Service Provider and you charge your customers by
volume, this will be essential to your business. If you are a customer
of an Internet Service Provider that charges by data volume, you will
find it useful to collect your own data to ensure the accuracy of your
Internet charges.
There are other uses for network accounting that have nothing to do with
dollars and bills. If you manage a server that offers a number of different
types of network services, it might be useful to you to know exactly
how much data is being generated by each one. This sort of information
could assist you in making decisions, such as what hardware to buy or how
many servers to run.
The Linux kernel provides a facility that allows you to collect all sorts
of useful information about the network traffic it sees. This facility
is called IP accounting.