End-to-End Performance Management in Convergent QoS-enabled Networks Wolfgang Haidegger 1 , Peter Reichl 1 , Nikolaus Jozefiak 2 , Martin Teufel 2 1 Telecommunications Research Center Vienna (ftw.), Donaucitystr. 1, A-1220 Vienna, Austria {haidegger | reichl}@ftw.at 2 Institute of Communication Networks (IKN), Vienna University of Technology, Favoritenstr. 9/388, A-1040 Vienna {nikolaus.jozefiak | martin.teufel}@tuwien.ac.at Abstract This paper presents an end-to-end performance management architecture for telephony applications in heterogenous and convergent networks. An abstract model for QoS management of a communication system is used to derive basic building blocks and functions. Based on the TMN structure of the ITU-T, a technology-independent framework for end-to-end perfor- mance management is proposed, including detailed descrip- tions of important function sets. Finally, an example scenario provides useful insight into the validity of the proposed approach. Keywords: TMN, performance management, convergent net- works, heterogeneous networks, QoS, managed Internet 1 Introduction As on of the most important general trends in communica- tions over the last few years, a steady merging of the traditional world of telecommunication with the new world of Internet ser- vices can be observed, resulting in new network type, i.e. “con- vergent networks”. This development creates a major challenge as far as applying Quality-of-Service (QoS) criteria of the plain old telephone system (POTS) is concerned. This is of specific importance for the telecom providers as telephone applications will still have to provide familiar QoS also over heterogenous (i.e. combined circuit-switching and packet-oriented) networks. This paper investigates heterogeneous networks from a man- agement point of view. We focus on the provision of an end2end performance management framework which guaran- tees a smooth interworking between packet and circuit switch- ing networks. To this end, Section 2 reviews a general model for QoS management [1] that will be used to characterize the framework for a telecommunication management network (TMN) of a heterogeneous transport network. Hereby, we aim at using as many of the ideas developed by the ITU-T as possi- ble, as a lot of experience and background knowledge about telephony networks has been put into the relevant recommen- dations, many of them being technology transparent. This is especially true for the TMN-layer structure defined in [2]. We will demonstrate that this structure exactly addresses the needs of the different user types of a telecommunication network (TN) and thus is valid for heterogeneous networks in general and packet-oriented networks in particular. Addition- ally, for the managed Internet a new general organizational structure for the management network is proposed, based on the "Internet domain" as basic organizational unit. The technol- ogy transparency also holds for most of the ITU-T specifica- tions for end2end performance management [3], which thus form the basis for the ideas presented in Section 3. Finally, Section 4 will provide an example scenario for a Multi-Protocol Label Switching (MPLS) enabled network, fill- ing the introduced functions of the various management layers and from performance management with contents that is backed up by the relevant IETF specifications. Section 5 sum- marizes the paper and draws essential conclusions. 2 A QoS-driven Approach for Managing Con- vergent Telecommunication Networks 2.1 QoS Building Blocks and Functions In order to provide consistent QoS for a variety of services over different types of networks from application to application within the customer premises equipment (CPE), i.e. end-to- end, the framework presented in [1] identifies the following three QoS building blocks related to communication resources: • The network contains resource managers for bandwidth, CPU and buffers both for transport and access media. This entity determines the physical and transport layer parame- ters which can be used to actually achieve QoS as delivered by the network. • The communication subsystem provides communication- related functions (thus enhancing network services) for applications as well as resource managers, most notably the configuration of protocols for service support. • A generalized operating system supporting both the com- munication subsystem and the application process within end systems contains resource managers for processor capacities, buffer space etc. These QoS blocks have to be managed both at network setup time and during its operation, using the following functions [1]: • QoS definition: The requested service including QoS parameters, general service and type-of-service parameters has to be defined on three different levels, i.e. network level (performance of NEs and interfaces), service application level (QoS performance), and business level (performance of business processes of an enterprise). • QoS mapping: Based on the different levels of QoS defini- tions, some kind of automated mapping between the QoS parameters is necessary both at the customer-system inter- face and between system internal interfaces. • QoS negotiation: The service requirements have to be dis- tributed among all entities involved, yielding both local and end-to-end negotiations. • QoS maintenance and monitoring: Once a certain QoS has been agreed upon, monitoring activities ensure that the negotiated QoS will be indeed be supported while the appli- cation is running.