[c-nsp] NetFlow for billing on 6500/SUP720-3B

[Andrew Miehs]

Are you really sure you want to bill based on Netflow?

I used to look after a network with 7206 as edge routers and implemented
"Netflow" billing for them.
The concept was great, and you could provide all sorts of interesting data

HOWEVER

After having implemented this, I do not believe that such a solution can be
made to scale. You need to make sure that your database with IP address
assignment per customer is also kept up to date! Re-rating traffic can be
very time consuming. You will end up with way too much data. We had written
our own netflow collector which was doing aggregation for us based (version
9 netflow didn't exist back then).

At some stage or other someone will need to look at the cost of billing vs
cost of the traffic. Your product department should weigh these costs
against each other.
At the end of the day, the customer doesn't really care whether VPN traffic
is free. He cares how high his bill is at the end of the month.

I would NOT use span ports on your switch. You normally only have 2
available, and you will need these at some stage for debugging purposes.
As suggested you could possibly use TAPs and measure your traffic with some
device off the TAPs, or as per your old solution route via your ?FreeBSD?
box.

I can only strongly recommend, try to avoid IP/ Netflow accounting if anyway
possible.


Best regards,


Andrew