The 95th percentile is a mathematical
calculation widely used to determine billings for
Internet connections that are provided as "burstable"
(variable rate) bandwidth.
Essentially, when you subscribe to a service that
includes a specific network bandwidth
allowance you are permitted to consume as much
bandwidth as you wish up to a specified limit. As
long as your monthly consumption is at or below this allowance level
there are no additional fees. If, however, you exceed your allowance
then you are invoiced for the additional bandwidth you consume.
This tutorial explains how your actual bandwidth
consumption is calculated and how this information is used to determine
any additional service charges that may apply to your EPI hosted
service. It is important when choosing a subscription for a bandwidth
allowance that you choose a bandwidth allowance suitable to your needs.
This tutorial explains how your actual bandwidth
consumption is calculated and how this information is used to determine
any additional service charges that may apply to your EPI hosted
service. It is important when choosing a subscription for a bandwidth
allowance that you choose a bandwidth allowance suitable to your needs.
Metering Your Consumption
Bandwidth consumption is a calculated
value. It works like this:
-
Every 30 seconds EPI takes readings off of the
network switch that services your account. These reading return the
amount of network traffic that has passed through the port that
services your equipment, returning the number of bytes of information
that has entered and left your service.
-
These values are added together to provide five
minute totals. These totals are then translated into kilobits and
divided by the number of seconds that have passed in order to
establish the total amount of bandwidth that entered and left your
service, expressed in kilobits per second (Kbps). Bandwidth is
calculated separately for both inbound and outbound traffic and your
bandwidth consumption is the sum of these two values.
At the end of each month these
readings are sorted and the top 5% of these readings are
removed. The next highest reading (called "the 95th
percentile") determines if any excessive use of
network traffic has occurred and determines the amount
of excess service fees that would apply.
Here is a simple example
that illustrates what we mean:
Over a period of 500 minutes, 100 readings
of both incoming and outgoing traffic have been recorded. Assuming the
billing period is also 500 minute, then the top 5% of these
100 readings (the top 5, in this case) are ignored, and you
are billed at the value of the 95th reading.
If the top 10 readings of this set of 100 were:
| Top 10 Entry |
Reading |
Comment |
| 100 |
2,090 Kbps |
Ignored (top 5%) |
| 99 |
1,790 Kbps |
Ignored (top 5%) |
| 98 |
1,200 Kbps |
Ignored (top 5%) |
| 97 |
960 Kbps |
Ignored (top 5%) |
| 96 |
840 Kbps |
Ignored (top 5%) |
| 95 |
825 Kbps |
** "95th Percentile" |
| 94 |
814 Kbps |
|
| 93 |
793 Kbps |
|
| 92 |
712 Kbps |
|
| 91 |
710 Kbps |
|
In this case, even though you sometimes sustained
traffic at speeds as high as 2,090 Kbps, your actual
95th percentile consumption was 825 Kbps. If your
subscription included 1,000 Kbps of network
traffic then your usage is well below your subscription
allowance.
What happens if you exceed your Allowance?
If you exceed your allowance you will be invoiced for
the additional bandwidth that your service consumed.
These additional fees are invoiced at a fixed rate, as
defined by your signed Sales Agreement.
Can I increase my Bandwidth Allowance?
Yes. For information on increasing your Bandwidth
Allowance please speak to your EPI sales representative.
Is there a way for me to view how much traffic my
service is using?
