Creating C++ client app for some abstract windows server - how to manage TCP connection to server speed?

So we have some s开发者_运维百科erver with some address port and ip. we are developing that server so we can implement on it what ever we need for help. What are standard/best practices for data transfer speed management between C++ windows client app and server (C++)?

My main point is in how to get how much data can be uploaded/downloaded from/to client via his low speed network to my relatively super fast server. (I need it for set up of his live stream Audio/Video bit rate)

My try on explaining number 3. We do not care how fast is our server. It is always faster than needed. We care about client tyring to stream out to our server his media. he streams encoded (via ffmpeg) live video data to our server. But he has say ADSL with 500kb/s of outgoing traffic. Also he uses some ICQ or what so ever so he has less than 500 kb/s per second. And he wants to stream live video! So we need to set up our ffmpeg to encode video with respect to the bit rate user can provide. We develop server side and client side. We need a way of finding out how much user can upload per second currently (so value can change dynamically over time)

Check this CodeProject Article it's dot-net but you can try figure out the technique from there.

I found what I wanted. "thrulay, network capacity tester" A C++ code library for Available bandwidth tracking in real time on clients. And there is "Spruce" and it is also oss. It is made using some of linux code but I use Boost library so it will be easy to rewrite.

Offtop: I want to report that there is some group of people on SO down voting on all questions on this topic - I do not know why they are so angry but they deffenetly exist.