Facing demands for high performance services, network operators are challenged by upgrading the level of management of their networks. But providing inter-domain Quality of Service (QoS) guaranteed services has to bring incremental revenues to the involved operators realizing needed evolutions of their network infrastructures. Beside these upgrades, operators are not ready to disclose information (e.g. network topologies and capacities) that would simplify the process of establishing end-to-end QoS guaranteed connection. In previous works, we have proposed and defined the notion of network operator alliance. Such an alliance would regroup operators which would find interest in cooperating and where some administrative costs would be shared and revenues split so that incentives to deliver inter-domain QoS guaranteed services would be met. Furthermore, confidentiality and business rules would be determined by the alliance participants. In a previous work [PDDS09], we proposed an architecture for inter-domain service delivery which includes extensions for Operation Support Systems (OSS) and control planes. This paper depicted the implementation of this architecture that covers network management at different plane levels and which has been tested with 5 emulated networks in our lab.

In this paper, we investigate the routing problem for dynamic traffic demands providing differentiated types of service across the network. Two classes of traffic are considered: QoS traffic and best-effort traffic. We propose a comprehensive offline/online routing solution that enables service providers to satisfy the demands of customer traffic flows while respecting the traffic priority. As a first step, an offline global optimization tool is used for network dimensioning. It aims to minimize the number of optical and electrical ports required in the network in order to satisfy a given set of high priority demands. Once the network's nodes are dimensioned, the network can be over-dimensioned to carry additional best-effort traffic requests. The latter set of traffic is routed by means of an online sequential optimization tool. Low priority traffic are divided into two subsets according to the requested capacity of the demands. This capacity may correspond either to an optical channel data rate (lightpath demands) or to a fraction of that rate (electrical demands). Our sequential optimization tool proceeds automatically to the grooming of the electrical demands into grooming demands. The network performance is expressed as the ratio of the number of rejected/blocked requests to the total number of requests

Virtual concatenation (VCAT) is an SDH/SONET network functionality recently standardized by the ITU-T. VCAT provides the flexibility required to efficiently allocate network resources to Ethernet, fiber channel, ESCON and other important data traffic signals. The aim of this paper is to quantify the savings in network resources provided by VCAT, with respect to contiguous concatenation (CCAT), in SDH/SONET mesh transport networks bearing protected scheduled connection demands (SCDs). We define mathematical models to quantify the add/drop and transmission resources required to instantiate a set of protected SCDs in either a VCAT-capable or a CCAT-capable network. Quantification of transmission resources requires a routing and slot assignment (RSA) problem to be solved. We formulate the RSA problem in VCATand CCAT-capable networks as two different combinatorial optimization problems: RSAv and RSAc, respectively. Protection of the SCDs is considered in the formulations using a shared backup path protection (SBPP) technique. We propose a simulated annealing (SA) based meta-heuristic algorithm to compute approximate solutions to these problems (i.e., solutions whose cost is close to the cost of the optimal ones). The gain in transmission resources and the cost structure of add/drop resources making VCAT-capable networks more economical are analyzed for different realistic traffic types (ESCON, GbE, fibre channel, voice).

Automatically switched circuit establishment is a big step for the operators towards the automation of transport services. The aim is to reduce OPEX while improving service capabilities through a distributed generalized multi-protocol label switching (GMPLS) control plane. Nevertheless, the control plane may not operate on its own and, hence, network operators need a holistic service production platform where intensified traffic engineering (TE) capabilities exist when operating the control plane. The aim of this paper is to point out and discuss issues to be addressed and to provide guiding principles as well as a policy-based management (PBM) solution pertaining to enhanced TE related to the GMPLS control plane protocols and the corresponding network management issues.

We present algorithms that compute the routing and wavelength assignment (RWA) for scheduled lightpath demands in a wavelength-switching mesh network without wavelength conversion functionality. Scheduled lightpath demands are connection demands for which the setup and teardown times are known in advance. We formulate separately the routing problem and the wavelength assignment problem as spatio-temporal combinatorial optimization problems. For the former, we propose a branch and bound algorithm for exact resolution and an alternative tabu search algorithm for approximate resolution. A generalized graph coloring approach is used to solve the wavelength assignment problem. We compared the proposed algorithms to an RWA algorithm that sequentially computes the route and wavelength assignment for the scheduled lightpath demands.