I had to set my WAN Connection Buffer Size to 40 and 10 packets for my connections which have 2 Mbps and 500 Kbps upload respectively. I did that in order to have only 250ms of buffer, which means my connections are usable even when I’m uploading some big file. Otherwise, any large upload kills the internet connection.
The side effect is that both my connections have a very small download buffer. They are 15 Mbps and 10 Mbps, so I have only 33ms and 12ms of download buffer respectively, which is too low.
So I think it would be nice to have an option to set different WAN Connection Buffer Size for download and upload on each connection.