Nogales Dorado, BorjaVidal Fernández, IvánValera Pintor, FranciscoSánchez Agüero, VíctorLópez, Diego R.2023-12-112023-12-112024-03IEEE Software, 41(2), March-April 2024, Pp. 88-970740-7459https://hdl.handle.net/10016/39051Network Functions Virtualization (NFV) is a fundamental enabler in 5G networks, automating service deployment through softwarization and virtualization. However, challenges remain in providing network connectivity to service components, commonly referred to as Virtual Network Functions (VNFs), deployed on different domains. A usual approach to enable such connectivity is to rely on layer-3 routing from Internet service providers. However, this approach presents limitations to preserve isolation among remote VNFs, and may require undesirable network configurations. This paper proposes a novel connectivity orchestration service for multi-domain NFV ecosystems to address these limitations. The service is based on a set of interconnected software components that are deployed on every NFV domain. Connectivity is automatically provided to remote VNFs over the overlay network formed by these components using Software-Defined Network (SDN) technologies. The service has been prototyped using open-source software, being validated on a real NFV ecosystem.7engThis work is licensed under a Creative Commons Attribution 4.0 LicenseAtribución-NoComercial-SinDerivadas 3.0 España5G mobile communicationSoftwareOverlay networksEcosystemsRoutingIP networksVirtualizationresearch articleTelecomunicacioneshttps://doi.org/10.1109/MS.2023.3304854This work is licensed under a Creative Commons Attribution 4.0 License8897IEEE SoftwareAR/0000033648