Read up on how to use QOS (Quality Of Service) for your router (probably in the manual, if not, google is your friend) as it does support it. I have a DLINK 504t with 'QOS' capabilities, but I put that in quotations because I find it completely useless as it doesn't seem to change bandwitdh allocations at all, I hope for your sake it is not the same with your router. If that doesnt work for you I dont think you will be able to allocate bandwidth from within the router itself, you may have to explore other options such as limiting the bandwidth from within the target device itself using third party software - if the device supports it (windows/mac/linux/mobile dev/game console????)
