It has come to the attention of Atlantic Metro Communications staff that some of our competitors have so called “shady” bandwidth billing practices. We won’t get into naming names or divulging the practices they employ to over charge you once you are hooked up to their service and bound by a contract.

Atlantic Metro Communications believes in being upfront with its customers about its bandwidth billing policies. Below we will explain the 95th Percentile bandwidth billing standard which is the most common for ISPs across the globe. Atlantic Metro Communications does offer per Gigabyte of Data Transfer billing as well. Per GB billing is most common with managed servers / dedicated servers and Content Acceleration services that we offer.

The 95th percentile is a widely used mathematical calculation to evaluate the regular and sustained utilization of a network connection. It is commonly used among all major internet transit and peering networks, as well as data centers and ISPs for both capacity planning and/or calculating usage.

The 95th percentile is a good number to use for billing as it can allow the customer throughput bursts without additional financial compensation. Basically the 95th percentile says that 95% of the time, the usage is at or below this amount.

Conversely, usage could be above that amount up to 5% of the time. There are important factors to percentile calculation:
Sampling interval, or how often samples are taken (called also “data points”). A percentile is calculated on some set of data points. Every data point represents the average bandwidth used through the sampling interval, calculated as the number of bytes (or KB/MB/GB etc.) transferred divided by the sampling interval length in seconds (effectively representing the average utilization for single sampling interval). The number is expressed in a data transfer rate as bits per second (kbit/s/Mbit/s/Gbit/s).

Bandwidth is measured (or sampled) from the switch or router port assigned to each customer. In most cases this is done every 5 minutes via SNMP poller. 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 ‘billable utilization’ for the month. 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 utilized at a higher rate for up to 65 min a day with no financial penalty.

Atlantic Metro Communications example real-time bandwidth reports with 95th percentile indicators.

All Atlantic Metro Communications customers are provided real-time bandwidth statistic via our customer portal 24 hours a day.

This entry was posted on Sunday, September 7th, 2008 at 4:43 am and is filed under News. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.