We have about 40 braches and they are connected to AT&T cloud by BGP routing protocol via T1 or ATM. All the servers are located in our headquarter. Sometimes, if one user in remote location downloads big files, the whole remote site is down. Each site has router connected to the AT&T and the switches are connected to the router. We'd like to implement QoS in LAN for all the switches so we can manage/control the bandwidth by port levels. We don't have voice network, it is only for data network. Please be advised that how we implement QoS in the switch in our network.