What is Bandwidth?
Bandwidth Definition: 1) A term used to describe the throughput capacity of a given network medium or protocol.
2) Bandwidth is the amount of information that can be carried in a given time period (usually a second). The higher the bandwidth, the more data can be transferred in bits per second (bps).
| Bandwidth Units of Measurement |
|
| bit |
Smallest unit of digital information (ones and zeros) |
Typically used to indicate storage space. Each letter in a document requires 1 byte of storage. Most hosting providers express data transfer in 'GB per month' for virtual, VPS and dedicated hosting plans. They usually equate 1 GB = 1000 MB. |
| byte |
A set of 8 bits |
| KB |
1024 bytes |
| MB |
1024 KB |
| GB |
1024 MB |
| TB |
1024 GB |
|
| bps |
bits per second |
bits (binary digits) are typically used in data transfer rates. In the Web hosting industry, many Colocation hosting providers express data transfer limits in bits per second. |
| kbps |
kilobits per second = 1000 bits per second |
| mbps |
million bits per second = 1 million bits per second |
| gbps |
gigabits per second = 1 billion bits per second |
| tbps |
terabits per second = 1 trillion bits per second |
Table 1.3: Bandwidth Units of Measurements
Instead of measuring the total number of GB of data transferred in a given month, many Colocation providers charge for bandwidth using a 'connection average' over the month, measuring the average 'data throughput per second'. For example, 1 mbps means that you can 'average' 1 mbp/s for the month. NOTE: 1 mbps is 1 megabit per second. Different to 'bytes', where 1 byte = a set of 8 bits.
For some excellent information on bandwidth measurements, visit Data Transfer Rates - A Primer.
Bandwidth Billing
Colocation hosting providers typically choose one of three models to determine how much bandwidth you have used per month. These can be defined as follows:
[A] Throughput Traffic Model » Calculates the amount of data transferred on the server in a 1 month period. The bill represents the customer's actual usage for that month. Measures in GB (Gigabytes). Ask your Colocation provider if they equate 1 GB = 1000 MB or the technically correct 1 GB = 1024 MB. This is good to know if you want accuracy.
[B] Capped Bandwidth Model » Clients buy a 'bandwidth cap' or 'maximum bandwidth' and all traffic is passed up to this cap. This option allows customers to know their monthly fee up front. Businesses can better control and plan their monthly expenditure without fear of exceeding their monthly bandwidth quota.
[C] 95th Percentile Bandwidth Model » The 95th percentile is computed by sampling the inbound and outbound data transfer at your connection point at 5-minute intervals over a 1-month period. The top 5% of samples from either the inbound or outbound throughput are discarded and the next highest reading becomes the bandwidth value used on the monthly bill.
The customer selects and prepays for a minimum bandwidth commitment. Overage fees are charged in the event the client utilizes bandwidth in excess of their pre-determined maximum. The 95th percentile is often used when calculating data transfer averages (measured in kbps/mbps).
Burstable Bandwidth
Burstable bandwidth refers to the data transfer speed you server/s can burst too. For example, a Colocation provider can state a 100 kbps plan, burstable to 1 mbps. Contact your hosting provider to find out their 'overage charges' when you exceed your 'average'. The amount you can burst to is a reflection of the hardware, network connections and speed.