Dynamic resource configuration in DiffServ networks: control plane mechanisms and performance evaluation of a traffic control API

Voice, video and multimedia applications are sensitive to the QoS provided by the underlying IP network. The DiffServ architecture offers a set of QoS mechanisms for IP networks. The "binding" of the applications QoS needs with the QoS features offered by the DiffServ networks is still an open problem. The simplest approach is to have a static configuration of QoS and therefore no direct interaction in the control plane between applications and QoS. We consider the advanced scenario, where the QoS mechanisms can be dynamically configured to follow the applications' need. For this scenario, a set of control plane interfaces needed for a whole end-to-end QoS architecture is defined. At the lower level, an internal interface ("Application Programming Interface" - API) in the QoS router is considered. This interface provides access to the DiffServ QoS mechanism available in a router and is used by the control logic running in the router itself. Then a QoS signaling protocol is considered, that allows external QoS clients to dynamically access the QoS services provided by the network. Finally the interaction of a session level signaling protocol (i.e., the SIP for IP telephony) with the QoS protocol is defined. A testbed implementation of the proposed architecture and a set of performance tests on the internal QoS API are reported.