Re: reverse proxying exchange 2013, rdp over ssl and sstp vpn

For RDP you need streaming, ea. vpn example:

# load balance your vpn servers

worker_processes 2;
error_log logs/error.log;

events {
worker_connections 16384;
}

# http {
# ... your usual http block ...
# } # http end

stream {
error_log logs/stream_error_openvpn.log;

upstream backend {
hash $remote_addr consistent;
server 192.168.99.3:8443;
server 192.168.99.4:8443;
server 192.168.99.5:8443;
}

server {
listen 443 so_keepalive=on;
proxy_connect_timeout 300s;
proxy_timeout 300s;
proxy_pass backend;
}

}

You can't mix stream ports with http(s) ports so you're going to need to route more then 1 port.
See also http://nginx.org/en/docs/stream/ngx_stream_ssl_module.html
And with this version http://nginx-win.ecsds.eu/ you can do it all on Windows.