## 4 Integrated Approach for QoS Assurance in IP/Optical Networks  
In this section, we propose an approach to handle connectivity (transport) and service-level QoS in an integrated way. As described in Sections 1.1 and 2, research works in the literature handle service management and QoS assurance separately. Therefore, our aim is to tackle both issues at the same time and in an aligned way in the context of IP/optical networks, taking into account QoS from the  
Figure 3: AGAVE’s functional architecture. Extracted from [19]. application layer to the physical (optical) layer. Transport-level QoS is assured by combining techniques to anticipate to traffic demands and impairment-aware lightpath provisioning (IA-RWA). Application-level QoS is assured with tailored service management, which is achieved by an adaptation of the service-oriented optical network architecture described in Section 2.1, coupled tightly with traffic-driven lightpath provisioning and IA-RWA. Besides assuring QoS in an integrated way, our proposed approach will enable new business models for IP/optical networks, such as provisioning as a service. That is, the offer of efficient, quality-enabled transport of user-driven services over IP/optical networks 'as a service' by enabling an interface for adaptation of these smart services to connectivity requests on backbone optical networks, especially GMPLS-managed (see USI in Figure 4). Such a model would decouple the innovation of services and service logic from protocols and network elements, support service portability between systems, with relocation and replication in the lifecycle, and support QoS assurance both in the setup and during the life of the connectivity services associated to the user-driven or smart services. Figure 4 illustrates the proposed architecture to assure QoS in IP/optical networks that integrates the features of anticipation of traffic demands (in the form of traffic-driven lightpath provisioning) and impairment-awareness in the lightpath provisioning process, along with decomposition of services into lightpaths. This architecture is based on the service plane concept described in Section 2.1 and can be implemented in a centralized or distributed way, that is, with a single or several service plane nodes. If it is centralized, the service plane node contains the SCE and SDE elements highlighted in gray. The proposed architecture will be implemented in a testbed infrastructure called ADRENALINE Testbed(r), which is managed by the Centre Tecnologic de Telecomunicacions de Catalunya (CTTC). ADRENALINE's architecture was conceived to explore cost-efficient solutions to address the ever-growing demands of IP data traffic, together with the need for replacing the SDH nodes in Internet backbone networks. The testbed leverages reconfigurable wavelength-routed network functionalities with connection-oriented Ethernet technologies, which are both controlled by GMPLS-enabled IP/optical nodes. For further information about the testbed, the interested reader is referred to [20]. Generically, the functions of a service plane can be split in two logical elements: one containing information about the services (service data element, SDE) and another managing the translation of IP traffic and services/applications into provisioning requests. Note that these elements are named 'Service virtualization' and 'Service adaptation' in Figure 1. The SDE is essentially a database for service characterization. The other element, called service control element (SCE), is the one performing connectivity adaptation and service virtualization using information from the SDE, as well as QoS policies from the pre-established SLAs. These two elements are highlighted in gray in Figure 4. Note that the network customers ('User' in Figure 4) interact with the SCE by means of a user-service interface (USI), more precisely with the connection administration control (CAC) element of the SCE.