sjltech.uk wrote: Sounds like something QoS should be able to sort out, might be worth having a look at this link, although the example is running an internal web server, the principle seems to hold with what you are trying to achieve:
http://www.draytek.co.uk/support/guides/kb-vigor-qos
('fraid it's a logon to read one)

Strangely enough, I had tried that previously and still had the defined class. What I had missed however, was to actually make the rule active.. doh!

Thanks for pointing me to look at it again - it seems to be doing the trick

Just to confirm this for the next reader, QoS is definitely the way for any problems like this. Routing doesn't split the bandwidth, just tells it where to go.

I run a game server that people log into to play an MMORPG and I was finding them complaining of lag if two of us in the office were streaming Netflix or downloading files etc. at the same time.

The answer was to allocate the port(s) which the game uses as a priority (in QoS setup) and give 25% of the bandwidth to that if necessary so nothing else could squeeze them. It takes a little while to figure out how the setup is configured. I felt that it wasn't terribly intuitive, but I did get it going.

No more complaints!