The introduction of Software-Defined Networks (SDN) and the evolution towards programmable data planes bring the opportunity to offload several functions to the data plane. In this context, the P4 programming language opens the door to the customization of data planes. It can provide packet processing functionalities that can be applied to improve network security among other areas. This paper presents P4Knocking, a P4-based port knocking implementation that can externally open ports that appear to be closed. The goal of bringing port knocking capabilities to the network is to seamlessly deploy firewall functions in the data plane, reliving hosts from dealing with unintended traffic. Our work presents a total of four implementations that involve data and control planes in different degrees. In this case, P4Knocking can provide a more transparent and efficient way to deploy the port knocking service compared to a host-based port knocking implementation. In fact, it requires no specific purpose externs apart from registers, hence its higher portability and flexibility with local or remote control planes.

In an increasingly interconnected world, new opportunities for telecom-based services are emerging. Innovative applications profit from cloud versatility and scalability, but require a platform to combine the optimized 5G network fabric with the advancements in the domain of cloud computing, Software Defined Networking (SDN) and Network Function Virtualization (NFV). In this multi-domain context, we find that available service platforms are lagging, because they tend to be tightly coupled to a constrained set of technologies. In practice, we need the flexibility to deploy different microservices over a heterogeneous range of infrastructure types, aggregating various virtualization, orchestration and control mechanisms. Moreover, the integration of the service requires collaboration among a wide mix of actors (e.g. developers, operators, hardware/software vendors, infrastructure/service providers or vertical integrators). We propose a next-generation Platform-as-a-Service (NGPaaS), devised as a modular framework for the development and operation of network services, while targeting a high degree of both customization and automation. The presented architecture is built around a workflow-based orchestrator which coordinates custom-built tasks across a tailored group of specialized infrastructure or platforms. We also explain how NGPaaS enhances DevOps-principles, to achieve a more efficient integration process across the many isolated administrative domains in the modern telco landscape.

Global System for Mobile communication - Railway (GSM-R) is widely used for operational communications between train and signaler. However, there is a need to define a successor that addresses: obsolescence, radio spectrum demand and the enabling of a range of emerging digital applications such as radiobased signaling and Automatic Train Control (ATC). Therefore, the International Union of Railways (UIC) started the initiative to develop the Future Railway Mobile Communication System (FRMCS). This paper describes an Adaptable Communication System (ACS) that is being developed jointly by industry and railway operators as a possible successor covering all types of railways and all aspects of the FRMCS. A pragmatic approach is suggested that considers diverse railway settings and makes use of various radio access technologies. Countries, geographical regions and infrastructure managers differ concerning available radio technologies, but use of a suitable ACS could pave the way towards innovation in the railway sector. For this adaptive concept we discuss several network models and enhancements including satellite communications (SatCom), Software-Defined Networking (SDN) integration and antenna systems that support multiple bearers in one. For SatCom a software defined radio (SDR) prototype using random access is presented that is able to fulfill the requirements of ETCS. We found that SDN can be used for dynamically changing the access technology for critical and noncritical railway use cases. Furthermore, we present an antenna prototype that can be used for 5G, GSM, WLAN and LTE in parallel which saves limited mounting surface on the train.

5G standard emerges at a particular time in technology history when cloud transforms deeply almost all industries and services: it becomes obvious that innovations have to be made cloud-native for being successful. 5G must become the ubiquitous fabric blending universal connectivity (to humans, robots, sensors...) with cloud versatility and scalability. For realizing this vision, another model than laaS must be adopted, the Platform as a Service (PaaS), which should be built to support telco-grade requirements and combine all sort of third-party applications. These are the core objectives of the Next Generation Platform as a Service (NGPaaS) project, a H2020 5G PPP Phase 2 project. The paper presents the project fundamentals, its architectural proposal and most relevant features.