Network slicing is gaining traction in Fifth Generation (5G) deployments and Beyond 5G (B5G) designs. In a nutshell, network slicing virtualizes a single physical network into multiple virtual networks or slices, so that each slice provides a desired network performance to the set of traffic flows (source–destination pairs) mapped to it. The network performance, defined by specific Quality of Service (QoS) parameters (latency, jitter and losses), is tailored to different use cases, such as manufacturing, automotive or smart cities. A network controller determines whether a new slice request can be safely granted without degrading the performance of existing slices, and therefore fast and accurate models are needed to efficiently allocate network resources to slices. Although there is a large body of work of network slicing modeling and resource allocation in the Radio Access Network (RAN), there are few works that deal with the implementation and modeling of network slicing in the core and transport network. In this paper, we present GNNetSlice, a model that predicts the performance of a given configuration of network slices and traffic requirements in the core and transport network. The model is built leveraging Graph Neural Networks (GNNs), a kind of Neural Network specifically designed to deal with data structured as graphs. We have chosen a data-driven approach instead of classical modeling techniques, such as Queuing Theory or packet-level simulations due to their balance between prediction speed and accuracy. We detail the structure of GNNetSlice, the dataset used for training, and show how our model can accurately predict the delay, jitter and losses of a wide range of scenarios, achieving a Symmetric Mean Average Percentage Error (SMAPE) of 5.22%, 1.95% and 2.04%, respectively.

Autonomous Fifth Generation (5G) and Beyond 5G (B5G) networks require modelling tools to predict the impact on the performance when new configurations and features are applied in the network. Modeling modern networks through traditional mathematical analysis can lead to low accuracy, while the execution time and resource usage are high in network simulators. Machine Learning (ML) algorithms, and specifically Graph Neural Networks (GNNs), are suggested as a promising alternative since they can capture complex relationships from graph-like data, predicting properties with high accuracy and low resource requirements. However, they cannot generalize to larger networks, as their prediction accuracy decreases when input data (e.g., network topologies) is significantly different (e.g., larger) than the training data. This paper addresses the GNNs scalability issue by following a step-by-step approach, exploiting networking concepts to improve a baseline model. This work is framed in the 2021 International Telecommunication Union (ITU) and Barcelona Neural Networking Center - Universitat Politècnica de Catalunya (BNN-UPC) challenge. Results show that by following the suggested steps, applied on the RouteNet baseline developed by the BNN-UPC, can lower the Mean Average Percentage Error (MAPE) from 187.28% to 1.838%, improving the generalization significantly over larger graphs. Our approach is more simple than other solutions that participated in the challenge, but obtained similar results.

Data center networks (DCNs) connect hundreds and thousands of computers and, as a result of the exponential growth in their number of nodes, the design of scalable (compact) routing schemes plays a pivotal role in the optimal operation of the DCN. Traditional trends in the design of DCN architectures have led to solutions, where routing schemes and network topologies are interdependent, i.e., specialized routing schemes. Unlike these, we propose a routing scheme that is compact and generic, i.e., independent of the DCN topology, the word-metric-based greedy routing. In this scheme, each node is assigned to a coordinate (or label) in the word-metric space (WMS) of an algebraic group and then nodes forward packets to the closest neighbor to the destination in this WMS. We evaluate our scheme and compare it with other routing schemes in several topologies. We prove that the memory space requirements in nodes and the forwarding decision time grow sub-linearly (with respect to n, the number of nodes) in all of these topologies. The scheme finds the shortest paths in topologies based on Cayley graphs and trees (e.g. Fat tree), while in the rest of topologies, the length of any path is stretched by a factor that grows logarithmically (with respect to n). Moreover, the simulation results show that many of the paths remain far below this upper bound.

TCP flows from applications such as the web or ftp are well supported by a Guaranteed Minimum Throughput Service (GMTS), which provides a minimum network throughput to the flow and, if possible, an extra throughput. We propose a scheme for a GMTS using Admission Control (AC) that is able to provide different minimum throughput to different users and that is suitable for "standard" TCP flows. Moreover, we consider a multidomain scenario where the scheme is used in one of the domains, and we propose some mechanisms for the interconnection with neighbor domains. The whole scheme uses a small set of packet classes in a core-stateless network where each class has a different discarding priority in queues assigned to it. The AC method involves only edge nodes and uses a special probing packet flow (marked as the highest discarding priority class) that is sent continuously from ingress to egress through a path. The available throughput in the path is obtained at the egress using measurements of flow aggregates, and then it is sent back to the ingress. At the ingress each flow is detected using an implicit way and then it is admission controlled. If it is accepted, it receives the GMTS and its packets are marked as the lowest discarding priority classes; otherwise, it receives a best-effort service. The scheme is evaluated through simulation in a simple "bottleneck" topology using different traffic loads consisting of "standard" TCP flows that carry files of varying sizes.

We present a system for dynamic network resource configuration in environments with bandwidth reservation. The proposed system is completely distributed and automates the mechanisms for adapting the logical network to the offered load. The system is able to manage dynamically a logical network such as a virtual path network in ATM or a label switched path network in MPLS or GMPLS. The system design and implementation is based on a multi-agent system (MAS) which make the decisions of when and how to change a logical path. Despite the lack of a centralised global network view, results show that MAS manages the network resources effectively, reducing the connection blocking probability and, therefore, achieving better utilisation of network resources. We also include details of its architecture and implementation.

In this paper a novel methodology aimed at minimizing the probability of network failure and the failure impact (in terms of QoS degradation) while optimizing the resource consumption is introduced. A detailed study of MPLS recovery techniques and their GMPLS extensions are also presented. In this scenario, some features for reducing the failure impact and offering minimum failure probabilities at the same time are also analyzed. Novel two-step routing algorithms using this methodology are proposed. Results show that these methods offer high protection levels with optimal resource consumption.

In this paper, a network laboratory for distance learning of basic concepts in IP networking is presented. Through a web interface, students can choose various configurations of a real private network (number of routers and subnetworks, use of IPv4/IPv6, etc.), and learn about them using Linux network commands. The utilization of the virtual laboratory and how it is implemented are described.