A lot of applications have been designed to help us detect the bandwidth on a link (Link throughput capacity) connecting two servers such as iperf. Unfortunately, these softwares congest the network and calculate consequently the amount of traversed data over the time consumed.
Is there any method that allows to detect the available bandwidth on a link without congesting it knowing that the link default capacity is known to be around 1Gb/s? I mean maybe to check the OUT buffer in the kernel space frequently. Or maybe to detect by some means the traffic on the link, thereupon the available bandwidth would be its complementary.