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143:) from the switch or router and recorded in a log file. In most cases, this is done every 5 minutes. At the end of the month, the samples are sorted from highest to lowest, and the top 5% (which equal to approximately 36 hours of a 30-day billing cycle) of data is thrown away. The next highest measurement becomes the
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Critics of the 95th percentile billing method usually advocate the use of a flat rate system or using the average throughput rather than the 95th percentile. Both those methods favour heavy users (who have interest in advocating for changes to billing method). Other critics call for billing per byte
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of the link in question than tracking by other methods such as mean or maximum rate. The bytes that make up the packets themselves do not actually cost money, but the link and the infrastructure on either end of the link cost money to set up and support. This method of billing is commonly used in
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The 95th percentile allows a customer to have a short (less than 36 hours, given a monthly billing period) burst in traffic without overage charges. The 95th percentile says that 95% of the time, the usage is at or below this amount. Conversely, 5% of the samples may be bursting above this rate.
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Based on this model, the top 36 hours (top 5% of 720 hours) of peak traffic is not taken into account when billed for an entire month. Bandwidth could be used at a higher rate for up to 72 min a day with no financial penalty. Conversely, if peak traffic only appears for a brief instant and no
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Many sites have the majority of their traffic on
Mondays, so the Monday traffic determines the rate for the whole month. Some providers offer billing on the 90th percentile as an incentive to attract customers with irregular bandwidth patterns.
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transferred throughout the interval divided by the duration of the interval (e.g., 300 seconds). The resulting value represents the average use rate for a single sampling interval and is expressed as bits per second (see
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Take the max(in, out) for each interval and use that as the source. This method is more complex to implement as it requires processing of each sample but results are closer to estimating total volume of data sent and
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Take the sum(in, out) for each interval. This method is simple to implement and does account for symmetric traffic patterns; some ISPs use this method to approximate total volume of data sent and received.
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Calculate the 95% value separately for in-bound data and out-bound data and then take the maximum of those two values. This method is simpler to implement but does not correctly estimate symmetric traffic
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Inbound and outbound traffic is usually counted separately, as connections are full duplex allowing traffic in-bound and out-bound simultaneously. Some common algorithms are:
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peering arrangements between corporate networks; it is not often used by ISPs because such entities need committed information rates (CIRs) for planning purposes.
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is a widely used mathematical calculation to evaluate the regular and sustained use of a network connection. The 95th percentile method more closely reflects the
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based on peak use. It allows usage to exceed a specified threshold for brief periods of time without the financial penalty of purchasing a higher
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additional traffic is generated the billing amount can be substantially higher than
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Most ISPs use a five-minute sampling and 95% usage when calculating usage.
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of data transferred, which is considered most accurate and fair.
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95th percentile measurement on a regular bandwidth pattern
26:"Burstable rate" redirects here. Not to be confused with
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188:- Used to review bandwidth usage and with
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220:"Cogent's Latest Price Drop"
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