Control the downloading speed

Question

Is there any solution or suggestion to control the transfering speed of data.For example, the line is 5k, but i want to use 90%fo it to download a file?Thank you

Answer 1

Old post - new answer.
You didn't say how you are carrying out data transfer. But I can tell you a method we have used.
1. Data is transmitted block by block.
2. Transfer is controlled by the downloaded, not the downloader. (In other words, upstream is a server which will accept open, getBlock, and close requests from clients.)
3. When making a client request:
o Record the start time.
o Record the time when the data is returned.
4. When making each client request:
o Look at the turnaround time for the previous request.
o Assume there is 100% utilization during that period.
o Divide that time by the percentage utilization you want. (This gives a "delay".)
o Sleep from "now" until the delay period has elapsed.
o Make the getBlockRequest.
This is a conservative algorithm.
o It uses a percentage of the AVAILABLE bandwidth, not total bandwidth.
o It reflects load on the server as well as the load on the network.
o It reacts very quickly to changes in actual load.
o Like just about any other method, it is operating "in arrears"; the basic assumption is that conditions now are about like conditions in the past.
Drawback: If you have many more contenders for resources than there are resources available, then this algorithm delays everybody. You may prefer an algorithm that limits the number of simultaneous users - maybe by granting a token to each simultaneous user - up to the number which you want to handle simultaneously. This will allow those requesters to finish their work and get out of the way.