Auto-scaling techniques aim to keep the right number of active servers for the current load: if this number is too small we risk service disruption, but if it is too large we waste resources. Despite the interest in the efficient operation of this type of systems, no prior work has addressed auto-scaling techniques for Network Function Virtualization (NFV) with stringent reliability requirements such as those envisioned in 5G (5 or 6 nines). To achieve such levels of reliability, we need to account for both the activation delay until servers become available (i.e., the wake-up or activation time) and the fallible nature of servers (which may fail with some probability). In this article, we build on control theory to design an auto-scaling technique for a server farm for NFV that guarantees certain reliability while minimizing the number of active resources. We show that the use of well-established tools from control theory results in convergence times much shorter than those obtained with state-of-the-art reinforcement learning techniques. This shows that, despite the current trend to apply machine learning to all sorts of networking problems, there may be some cases where other techniques (such as control theory) can be more suitable.

The softwarization of mobile networks enables an efficient use of resources, by dynamically scaling and re-assigning them following variations in demand. Given that the activation of additional servers is not immediate, scaling up resources should anticipate traffic demands to prevent service disruption. At the same time, the activation of more servers than strictly necessary results in a waste of resources, and thus should be avoided. Given the stringent reliability requirements of 5G applications (up to 6 nines) and the fallible nature of servers, finding the right trade-off between efficiency and service disruption is particularly critical. In this paper, we analyze a generic auto-scaling mechanism for communication services, used to de(activate) servers in a cluster, based on occupation thresholds. We model the impact of the activation delay and the finite lifetime of the servers on performance, in terms of power consumption and failure probability. Based on this model, we derive an algorithm to optimally configure the thresholds. Simulation results confirm the accuracy of the model both under synthetic and realistic traffic patterns as well as the effectiveness of the configuration algorithm. We also provide some insights on the best strategy to support an energy-efficient highly-reliable service: deploying a few powerful and reliable machines versus deploying many machines, but less powerful and reliable.

Fifth generation (5G) and beyond systems require flexible and efficient monitoring platforms to guarantee optimal key performance indicators (KPIs) in various scenarios. Their applicability in Edge computing environments requires lightweight monitoring solutions. This work evaluates different candidate technologies to implement a monitoring platform for 5G and beyond systems in these environments. For monitoring data plane technologies, we evaluate different virtualization technologies, including bare metal servers, virtual machines, and orchestrated containers. We show that containers not only offer superior flexibility and deployment agility, but also allow obtaining better throughput and latency. In addition, we explore the suitability of the Function-as-a-Service (FaaS) serverless paradigm for deploying the functions used to manage the monitoring platform. This is motivated by the event oriented nature of those functions, designed to set up the monitoring infrastructure for newly created services. When the FaaS warm start mode is used, the platform gives users the perception of resources that are always available. When a cold start mode is used, containers running the application’s modules are automatically destroyed when the application is not in use. Our analysis compares both of them with the standard deployment of microservices. The experimental results show that the cold start mode produces a significant latency increase, along with potential instabilities. For this reason, its usage is not recommended despite the potential savings of computing resources. Conversely, when the warm start mode is used for executing configuration tasks of monitoring infrastructure, it can provide similar execution times to a microservice-based deployment. In addition, the FaaS approach significantly simplifies the code logic in comparison with microservices, reducing lines of code to less than 38%, thus reducing development time. Thus, FaaS in warm start mode represents the best candidate technology to implements such management functions.

5G is the next step in the evolution of operational networks, happening after the successful introduction of past generations like 3G or 4G. However, different with previous evolutions, in the case of 5G there is a confluence of novel technologies at different levels, ranging from the radio access to the virtualization technologies. Building, running and operating all of these new innovations is extremely challenging because of the novelty and the lack of previous experience on integrating them altogether. The base that sustains these new capabilities is the emergence of softwarized networks enabling automation, programmability and virtualization. The paper addresses the case of deploying 5G service slices by describing an architecture design for enabling orchestration in a multi-site environment, formed by 5G end-to-end facilities offered to vertical industries for experimentation, providing realistic situations for all the stakeholders on such multi-site environments (i.e., customers, providers, manufacturers, integrators, etc).

The evolution of the Internet has resulted in the deployment of new applicationlevel solutions to enhance the scalability and efficiency of content dissemination (e.g., content delivery networks and peer-to-peer systems).However, despite of this improvement on performance, the utilization of this type of solutions introduces new security concerns, as a content provider must necessarily delegate the role of distributing the content to third parties, and current security solutions, such as TLS and IPsec, do not allow authenticating the original content provider or the content itself in these scenarios.In this paper, we present SCoT, a transport-layer protocol that allows a content provider to bind protection to content, enabling content authentication at receivers regardless of any third party infrastructures that have been used to disseminate the content.Content authentication procedures are executed transparently to end-user applications.We implemented a fully operational prototype of the protocol in Java, including an API to support the development of SCoT applications.We utilized it to configure an experimentation scenario that served to validate a theoretical analysis of the SCoT throughput and to illustrate the performance that can be achieved in a practical deployment.The paper concludes describing a set of use cases of the protocol.

In this paper, we first further investigate the use of random decision policies for caching schemes, or probabilistic caching, in Content-Centric Networking (CCN). Our main objective is to provide a mathematical model for the combination of random cache decision and least recently used (LRU) replacement policy in the content store of CCN, called LRU-PC (LRU with probabilistic caching). This analytical model contributes to the improvement on proper caching selection probability per content router, in order to achieve a good performance considering different parameters, such as the popularity of the files, cache size and others. Based on these results, the paper further contributes by extending the LRU-PC with a secondary list holding a wider view of the names of content packets that transverse a CCN node. In this case, a segment is stored in the cache with a given probability when its name is stored in this secondary list, dubbing this mechanism LRU-PCSL (LRU with probabilistic caching and a secondary list). As LRU-PC, LRU-PCSL has a constant time complexity, is scan-resistant, presents low memory requirements and is possible to implement in hardware. Evaluation results show that LRU-PCSL increases overall cache performance compared with LRU and LRU-PC.

Content-Centric Networking (CCN) is a new paradigm where caching techniques play an important role. This is motivated by the addition of memory to core routers allowing to store the content traversing them. In this environment, several techniques have been proposed to increase the performance of the cache, and most of them are based on well-known ideas that are being used nowadays. In this paper, we propose a new cache decision policy, which is based on statistical filtering by using Bloom filters. Our proposal efficiently improves the hit probability of a CCN router taking into account the popularity and size of the catalogue, and this improvement allow clients benefitting of better download times and lower delays, and also reducing the server load. Furthermore, this method of filtering content takes advantage of techniques that have not been yet explored in this research field. We propose a mathematical model to characterize the decision policy, validating it by means of simulation.

This article gathers the foundational premises of the MEDIANET project as well as intermediate results obtained along its firsts two years. MEDIANET is a Spanish project founded by the Comunidad de Madrid government, which strives for a significant scientific advance in the future media Internet where important advances are necessary to allow end-users to perceive a good quality of experience. The network technologies objectives consist of the definition and validation of new proposals for the efficient transport of high bandwidth, real-time data flows in a decentralized way where the network provides mechanisms to seamlessly request and configure devices to increase the quality of experience perceived by end-users. Furthermore, new experiences with layer 2 networks and a cross-layer design will be tested with high bandwidth demanding media services. An important objective is to develop, evaluate in depth and implement on diverse platforms, a new low latency transparent bridge protocol based in on-demand path set up, suitable for campus and data center networks. The global result will be an integrated and independent advancement in future media Internet protocols, algorithms, switching architectures and standards.

A practical real-time mobile auction system must fulfill diverse constraints. In Rodriguez-Hernandez P.S. et al. (2002), we described a mobile auction system implemented with 433 MHz band modems. Nowadays, that system has become a standard in the Galician fish markets, which include the most important fishing port in Europe, Vigo (Spain). Although our system has been performing satisfactorily for four years, it is obvious that new technologies such as Bluetooth and IEEE 802.11 have shaped the wireless market and deserve our attention. In this paper, we evaluate Bluetooth in the context of real-time mobile auctions. As a result, we propose a novel approach to implement mobile auction systems by exploiting the park mode in Bluetooth specifications, which may also be useful for other remote-command applications with hard real-time constraints

In this paper, we analyze survivability issues of auxiliary Bluetooth location networks (BLN) for location-aware or context-driven mobile networks. We assume that there exist service servers that need to know user location in real-time, to send context-oriented information to user handhelds when necessary. The BLN transmits position information to service servers, without user participation. It is not subject to line-of-sight constraints and is supported by existing commercial handhelds. BLN users carry either a Bluetooth-enabled handheld or any mobile data terminal and a Bluetooth badge. The BLN is composed of wireless Bluetooth nodes, which establish a spontaneous network topology at system initialization. The BLN can coexist with other Bluetooth systems.

We propose a Bluetooth location network (BLN) for location-aware or context-driven mobile networks, such as m-commerce networks or e-museums. We assume that, in any of those scenarios, there exist service servers that need to know user location in real-time, to send context-oriented information to user handhelds when necessary. The BLN transmits position information to the service servers, without user participation. It is not subject to line-of-sight constraints and is supported by existing commercial handhelds. BLN users carry either a Bluetooth-enabled handheld or any mobile data terminal and a Bluetooth badge. The BLN is composed of small, wireless Bluetooth nodes, which establish a spontaneous network topology at system initialization. The BLN can coexist with Bluetooth devices that are not part of the location system, such as printers or headphones.