Bandwidth from Latency

Question

DUPE: http://stackoverflow.com/questions/729146/how-to-programmatically-check-internet-bandwidth-in-vc

Can we find the bandwidth from the latency of ping .If yes how is it done

Answer 1

No, generally speaking there not much or relation. See Wiki: Comparison of latency and throughput.

Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway.
— Andrew S. Tanenbaum.

Modern sneakernet can have incredible bandwidth (imagine e.g. sending 2 x 2TB disks via courier), while their latency is of hours or even days.

Answer 2

The two aren't related:

• Latency is the difference in time between when you send something and when the receiver gets it. There is an absolute minimum latency for all transmission governed by the distance and the speed of light.

• Bandwidth, used in the way you describe, is the amount of information that can be sent over a particular time. There is a physical limit on the amount of bandwidth you can have per volume it occupies (if we had computers made of pure energy that were as dense as possible), but it's unlikely we'll reach this anytime soon.

Some examples:

• Low latency, low bandwidth: Connecting to a congested terminal on a LAN.
• Low latency, high bandwidth: Transmitting over the Internet backbone.
• High latency, low bandwidth: Dial-up modem on a congested network.
• High latency, high bandwidth: Fill a car with hard drives and drive it to San Francisco. (This is sneakernet.)

Answer 3

There is however a technique called packet pair probing.

You send to packets one immediately after the other. In theory, the less bandwidth available, the more they will spread away in arrival time.