Colocation Basics - Colocation Terminology
Refers to the total amount of data transferred to and from your colocated equipment and includes web, FTP, email, and all other traffic that passes through our core routers. Network traffic that passes through your private VLAN but does not reach our core switches is not counted in your monthly usage. For example, you might have 2 colocated servers connected through a private VLAN utilizing 100 Mbps or 1000 Mbps Ethernet port to exchange data. An example of this might be a web server exchanging data with a database server. This data exchange is not seen by our core switches and therefore is not counted in your monthly bandwidth allocation.
Example: To better understand how connection speed (usually indicated in Mbps relates to total data transfer, consider this example. Suppose your have requested 1 Mbps of bandwidth per month. Complete utilization of a 1 Mbps connection equates to about 340 GB of transfer in a month. This figure assumes 100% usage 24 x 7 x 30. Consider a web page of the size indicated below:
Page size 30kb = 5,941,925 views per month
Page size 40kb = 4,456,448 views per month
Page size 50kb = 3,565,155 views per month
Page size 60kb = 2,970,954 views per month
To determine your monthly bandwidth needs, you will need to perform the following calculation:
- Determine your daily amount of anticipated data transfer.
Consider the number of interactive visitors, the amount of data each will transfer and the frequency of the transfer.
- Multiply that number by 30.5 (the average number of days in a month)
Ex. Your web site consistently has 5000 unique visitors per day. The average visitor transfers about 1.5 MBs of data (Yes MegaBytes). There are 30.5 days in a month. Therefore we have 5000 * 1.5 MB * 30.5 = 228,750 MBs of transfer per month.
- Calculate the number of GBs (GigaBytes) of transfer per month.
Each 1000 MBs is equivalent to 1 GB. From the above example, we have 228,750 MB / 1000 MB/GB = 228.75 GB per month of transfer.
- Determine the approximate connection speed required to support the level of transfer.
In the above case, we take 228.75 GB / (340 GB/1 Mbps) = .673 Mbps or 673 Kbps to support the indicated transfer at 100% utilization.
- Allow for growth by calculating 40% overhead availability.
This is critical since bandwidth utilization is NOT constant over the course of the day. There are peak times of utilization. We recommend that average utilization remain at or below 60% of the total capacity. In the above case, we have confirmed usage of .673 Mbps. We need to determine the factor necessary to calculate our actual need. Using 60%, we know that 100/60 = 1.667 so we multiply .673 * 1.667 = 1.12 Mbps. Based upon our services, you would need between 1 Mbps and 2 Mbps to provide effective service for your 5000 visitors per month.
The amount that you pay for your service each month. For colocation, this is a combination of your monthly bandwidth usage (calculated from the previous month, your rack space charges and any additional service or management fees as requested.
What is a "U"? (Unit of measurement for Colocation)
1U = 1.75" of Vertical Rack Space 2U = 3.5" of Vertical Rack Space 3U = 5.25" of Vertical Rack Space 4U = 7.00" of Vertical Rack Space. This measurement is used to indicate the total amount of rack space occupied by your colocated equipment.
MRTG (Multi Router Traffic Grapher)
A tool used to monitor the traffic load on network-links. MRTG generates HTML pages containing GIF images which provide a LIVE visual representation of this traffic. Another variant of this is known as PRTG (Paessler Router Traffic Grapher) and provides much more robust reporting and monitoring.
95th Percentile Explained
Samples of your actual bandwidth usage are taken every five minutes from your VLAN port on our core switch using PRTG and SNMP. In addition, we monitor Netflow packets on our core routers. We average the totals and post the result as a five-minute usage point on your report. Over the month, we will continue to plot the five-minute averages, which total about 8,640 points plotted on the graph.
We then take the top five percent of your usage (432 points, or 36 hours) and throw it out!
Your usage is determined based upon the highest remaining usage plotted. This method of billing provides you with a number of advantages. Any usage bursts that are untypical of your bandwidth requirements are not charged to you, and this equates to receiving the difference between average bandwidth and your highest 36 hours of bandwidth usage free each month.
We then give you access via the web to view your Daily, Weekly, Monthly and PRTG graph reports at any time. If your package(s) include a specific amount of bandwidth, any overage(s) will be billed at your contracted rate at end of the calendar month.
Our dedicated-based bandwidth is a burstable access, which uses the "sustained usage" formula to determine the monthly access rate. At the end of each month of service, based on readings taken every 5 minutes, which are placed in ascending order, the 95th percentile is determined as the "sustained usage rate".
One time charges that are incurred at the initiation of service. These charges generally cover our labor costs and the cost of any equipment required to implement your service.