In other words,You want to improve or control network traffic on your network,Quality of service (QOS) has to be implemented and any Cisco router can do this job.However because you want to set bandwidth no per application but for each computer on the network.In this case, QOS on the router is not be scalable.because if you have 20 PC ,more than 40 statements will be configured on the router.what`s about if you have 50 PC???
Therefore I will advice you to use a bandwidth management software.
Eg:http://bandwidthcontroller.com or others.
Kelly-Mukendi
Network support Engineer
Verizon Business-RSA