A prototype implementation for the IntServ operation over DiffServ networks

The integration of voice, data, and video services modified the target of networking technologies. Now, instead of simply providing best effort delivery, the network has also to address integration of services and quality of service (QoS) support. The applications should be therefore provided with means to describe the service they want to receive from the network. In the Internet, two major mechanisms have been studied and developed: Integrated Services and Differentiated Services. Combining Integrated Services (R. Braden et al., 1994), QoS mechanisms for end-to-end signaling at hosts and Differentiated Services (S. Blake et al., 1998), QoS mechanisms in the network core is one proposal for overcoming the limitation of either mechanisms when applied alone (Y. Bernet et al., 1999). Some of the open issues of Y. Bernet et al. are discussed and a concrete proposal is presented, which maps the IntServ Controlled Load Service into the DiffServ Expedited Forwarding "Per Hop Behavior". The proposed approach has been implemented under the Linux operating system. The implementation allows verifying of the correct functional behavior and provides a platform where more complete performance tests are possible.