Transactional bandwidth management holds great promise for the cable industry by allowing improved use of resources through statistical multiplexing and dynamic bandwidth assignment. This must occur in an environment in which Quality of Service (QoS)-enabled applications such as voice place very specific requirements on the network equipment and communication links. Any transactional changes must take place such that these applications continue to function correctly. The price to achieve this is increased complexity in management and control because bandwidth and QoS changes occur in real time. Per- flow queuing can be used to simplify the management and control associated with these changes and provide a deterministic mechanism to implement transactional bandwidth management. This paper explains the importance of per-flow QoS to the successful deployment of transactional bandwidth services and demonstrates how QoS can be provided end-to- end for transaction-based services.