Dynamic allocation of VS/VD in ABR service using active networking technology

When the available bit rate (ABR) service is deployed in wide area networks (WANs), the service experiences considerable round-trip time (RTT) due to its feedback control mechanism. The virtual source (VS) and virtual destination (VD) function is a recommended method to reduce the RTT. The VS/VD basically shortens control loops where feedback information circulates. The concept of VS/VD, however, has not been highlighted because its implementation is not so easy. We focus on the issue of dynamic allocation of VS/VD functionality in an ATM WAN and argue that active networking technology is suitable to elaborate the flat VS/VD functionality. The framework which makes the active networking technology coexist with ATM networks is presented and the details of the active VS/VD function are described.