Possible ba ma-control ang speed o download ng isang client sa isang network? DSL MODEM>ROUTER>CLIENTS
Yes, re-config the QoS part of your router. It will be a per PORT config.
For low end routers you can chose from High Priority to Low Priority.
On application stand-point, you can also set its priority.
ex. Gaming apps = Highest Priority
Downloading app = Lowest Priority
For high end router, this will depend on your network knowledge.
Must have atleast a CCNP certification.
You can also use some application/s, you can ask our co-spies if the have one.
Good Luck.