[c-nsp] Billing per Mb (Large ISPs)

[Tony]

Hi,

On Sun, 25 May 2014 04:04:52 +1000, Gert Doering <gert at greenie.muc.de>  
wrote:

> Hi,
>
> On Sat, May 24, 2014 at 08:47:45PM +0300, Artem Viklenko wrote:
>> we stop to bill per mb and move to bill by bandwidth.
>
> Where exactly is the difference of "bill per mb" and "bill by used  
> bandwith",
> except "a scaling factor"?
>
> gert

So just to clarify, I believe the OP is talking about billing per MByte  
(data transferred), not per Mbit/s (bandwidth usage).

For historical reasons in this wide brown land nearly all plans are based  
on a fairy low (by international standards) quota per month (eg.  
100GB/mon) and then either a $/GB excess, or the connection is  
shaped/throttled to a "minimal" speed after quota is exceeded (ie.  
64-256kbps, depending on ISP) to limit ISP's exposure to cost blow outs.  
The main reason for this is the cost of bandwidth. Up until recently  
transit costs were in the order of $50-$100/Mbps/month and backhaul costs  
(ie. within the country) were the same. This is due to a combination of  
long distances, sparse population and not much competition. So if the cost  
to provide 1Mbps (continuous usage) to a customer is $100/mon then once  
the customer uses more than about 300GB in a month you are losing money.

Every now and then a new ISP will emerge offering "unlimited" plans and  
they will quickly disappear as the customers they attract are those who  
are wanting to download TB/mon for $50/mon, which the economics just don't  
support. The average usage pattern across the whole range of customers  
(light to heavy users) at the moment is around the 40-70GB/mon (I believe).

To answer the OP's question, we were billing on a per MByte basis up until  
a few years ago. It was managed by netflow export that was then aggregated  
by destination IP in 30 minute blocks (from memory) to reduce DB storage  
requirements (it was stored in an RDB). There was then another table that  
was managed that tied customers to IP addresses. At the end of each month  
an SQL query ran along the lines of "select sum(usage) for each IP address  
for each customer, group by customer", this was then output to an HTML  
page that someone then transcribed into the accounting system to generate  
bills. Definitely manually intensive and definitely not scalable, it was  
used for in the order of 50 customers. Once transit prices dropped enough  
we ditched that and now bill based on contracted Mbps (ie. $/Mbps/mon with  
unlimited quota) the same way that we purchase.

There isn't an easy way to do it I don't think, most of the methods are  
grafted together in house. You could use netflow, or you could instead use  
something SNMP that graphs interfaces and also reports on MBtye usage  
(which is all traffic graphs are really, interface counter increment  
divided by time period).


regards,
Tony.