Tuning needed for slow RDP FreeBSD 9 -> Win 2008 R2

[Peter Olsson]

Desktop: FreeBSD 9.0-RELEASE amd64, generic kernel,
running Openbox. My WAN is about 1.2 Mbps, and I try
to run RDP to windows servers beyond my WAN.

RDP to a Windows Server 2003 SP2 is fast and works
without problems.

RDP to a Windows Server 2008 R2 is very slow,
and sometimes just disconnects.

I tried changing a couple of net.inet.tcp sysctl:
net.inet.tcp.recvbuf_max=10485760
net.inet.tcp.recvbuf_inc=65535
net.inet.tcp.sendbuf_max=10485760
net.inet.tcp.sendbuf_inc=65535
net.inet.tcp.recvbuf_auto=0
net.inet.tcp.sendbuf_auto=0
net.inet.tcp.sendspace=65536
net.inet.tcp.ecn.enable=1
net.inet.tcp.delayed_ack=0
net.inet.tcp.tso=0
net.inet.tcp.sack.enable=0
net.inet.tcp.path_mtu_discovery=0

Some in combination with others, and some by themselves.

I also tried net.link.ifqmaxlen=1024 in /boot/loader.conf.

Nothing has helped, do you have any ideas what I
should tune?

Thanks!

-- 
Peter Olsson                    pol at leissner.se