Adjusting window size and window scaling options, and buffers (mbufs).

kern.ipc.maxsockbuf=262144
net.inet.tcp.rfc1323=1
kern.ipc-nmbclusters=32768

net.core.wmem_max=8388608
net.ipv4.tcp_window_scaling=1
net.ipv4.tcp_mem = 98304 131072 196608

Register: \HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
Add DWORD named “TcpWindowSize” and set it to 131400 (decimal)
Tcp1323Opts should be set to 3 (rfc 1323 scaling and timestamps)
ForwardBufferMemory 8000
NumForwardPackets 6000