MPLS versus IP for Interworking of Wide Area Subsystems with QoS Guarantees

The paper analyzes two solutions (IP and MPLS) for interworking of network portions implementing different QoS technologies and belonging to diverse Autonomous Systems (ASes). While the implementation of QoS is a AS\´s concern, three topical problems should be solved at the interworking points (called Relay Points, RPs, in the paper): 1) the definition of the RP convergence technology, 2) the signalling between the RPs, 3) the bandwidth pipes dimensioning for flows traversing the heterogeneous network. The paper investigates these points and proposes a description of the Service Level Agreements available in the heterogeneous network as function of the RP protocol architecture. The RP stack proposed needs to interact with ASes QoS-solutions. It means that the RP QoS must be "mapped" on alternative technologies (DiffServ, IntServ, ATM and so on), implemented locally. This leads to the analysis of the traffic aggregation effect on the performance, e.g., if traffic requiring different performance is joined in one flow for technological reasons. The results reported, obtained through simulations, investigate this topic and allow providing operative solutions applicable in the field.