4. Conclusion

Service differentiation has long been an interesting challenge, as it requires the definition of a complete architecture of network mechanisms. Work carried out at the IETF has led to the construction of two approaches with different philosophies for giving better treatment to certain flows in the network. The first approach, IntServ, is based on the paradigm of resource reservation in network equipment. This implies that a context must be maintained in the routers for each flow, severely penalizing the scaling of this protocol. In order to offer better scaling, by concentrating the complexity of differentiation in network edge devices, the IETF has defined a second approach: DiffServ. In the DiffServ model, the role of routers varies according to their placement in the network. Entry routers are responsible for identifying and conditioning flows. The result of these actions is written...