Bandwidth test (meter) is a network service used to meter a speed of an internet connection by sending a one or more files of known size over a network to a distant computer (for example, your own computer), measures the time required for the files to successfully download at the destination, and thereby obtains a theoretical figure for the data speed between two or more points, usually in kilobits per second (Kbps) or megabits per second (Mbps).
Bandwidth test results vary greatly, even from moment to moment, and occasionally produce absurd or improbable figures. Factors that affect test results include: Internet traffic (speed generally decreases as volume increases) Variable propagation delays (can artificially inflate or degrade the result) Noise on data lines (has a real detrimental effect) The size(s) of file(s) used for the test The number of files used for the test The demand load on the test server at time of test Geomagnetic and/or thunderstorm activity Bandwidth or data transfer rate, is the amount of data that can be carried from one point to another in a given time period (usually a second).
Network bandwidth is usually expressed in bits per second (bps); modern networks typically have speeds measured in the millions of bits per second (megabits per second, or Mbps) or billions of bits per second (gigabits per second, or Gbps). Bandwidth is not the only factor that affects network performance: There is also packet loss, latency and jitter, all of which degrade network throughput and make a link perform like one with lower bandwidth. A network path usually consists of a succession of links, each with its own bandwidth, so the end-to-end bandwidth is limited to the bandwidth of the lowest speed link (the bottleneck).
Effective bandwidth is the highest reliable transmission rate a path can provide – is measured with a bandwidth test. This rate can be determined by repeatedly measuring the time required for a specific file to leave its point of origin and successfully download at its destination.
Please check this great service at: http://www.test-net.org/services/network-calculator/ or visit FREE SERVICES menu