configure link and buffer sizes
By default, the qlen is 1000 packets (for both HTB and netem). This is too small when we consider high BDP networks.
There are two issues:
1- htb buffer sizes: htb does not include the buffer size parameter. however the interface bufer size can be increased with a
ip link set DEV_NAME qlen BUFFER_SIZE
2- netem buffer size can be increased with the 'limit' parameter
I propose to consider a maximum BDP of 1000000 packets - this covers the (300Mbps; 650ms) use-case. There may be bufferbloat, but this seems better than the 1000 packets limits. We could think of estimating the BDP, but we need knowledge of forward and return link and makes it less generic. There may be a smarter way of doing it - such as in ip_scheduler job. Also it may be interesting to set a tunable parameter for this buffer.
I tested the merge request that is on the configure-link branch