GÉANT Multi-Domain Virtual Private Network (MD-VPN) provides an end-to-end international network service that enables scientists all over Europe to collaborate via a common private network infrastructure. The MD-VPN​ service can be used for connectivity between clusters, grids, clouds and HPC (high-performance computing) centres, allowing them to form v​​​​irtual distributed resources for third-party research projects. MD-VPN offers fast delivery of VPNs to end users and so can be used in a variety of ways, from a long-term infrastructure with a high demand for intensive network usage to quick point-to-point connections for a con​ference demonstration.​ VPNs are ideal for many-to-many (pee​r-to-peer) or one-to-many (central-site-to-satellite) environments, where each site can be allocated bandwidth according to its own requirements. Each site can support bandwidths from 155Mbps to 100Gbps (subject to availability).NRENs