It may be that your router's firewall is blocking the port used to carry out the firmware upgrade (port 6000).
A TCP port is an address associated with a program or process on a computer. For example, port 21 is commonly an FTP server, and port 80 is commonly a web server.
Often firewalls will block non-essential ports, so it is likely that you can temporarily reconfigure the router to allow traffic over port 6000.
You will need to enter your router's setup (web login page) to check these firewall settings and if necessary open up port 6000 to TCP traffic for the Stream Magic 6 / Minx Xi / NP30 using port forwarding.
Alternatively, you can move the Stream Magic 6 / Minx Xi / NP30 into the router's DMZ (where no port restrictions will apply) until the upgrade is complete.