Where and how do I change the TCP window size? I googled and found that /etc/sysctl.conf might be the place, but I added these settings and still got the same result and TCP window size.
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_syncookies = 1
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216