In TRS, you identify the target bandwidth you want each flow in each Traffic Class to have available to it under periods of congestion. During periods when there is excess bandwidth available, you can set policies for who gets first access to that excess bandwidth. Since the sum of all the guaranteed rates is less than the link speed, no congestion occurs, just smooth slowing and acceleration of application flows as link usage ebbs and flows. You buy a box and use it to manage the WAN links that you choose, implementing the policies that you choose. No ISP, Service Provider, IETF body, ATM Forum, multi-national committee or judicial body need be involved in the decision or implementation.
End stations are transparent to the implementation.
They are just running normal TCP processes. From a single point in the network you can influence the rate of traffic flows both into and out of your site. I believe that TRS is how QoS will really get implemented in networks because it is useful and can be implemented independently by different end users in a point-wise manner. TRS is on my list as one of the Next Big Things in networking. These features generally allow you to allocate bandwidth available to specific Traffic Classes using traditional queuing and CoS techniques.