Multiprotocol label switching and IP. Part 2. Multicast virtual private networks

For pt.1 see ibid., vol.9, no.3, p.68-72 (2005). Part I of this series discussed a solution for running multiprotocol label switching virtual private networks (MPLS VPNs) across a service provider's native IP network. Yet, MPLS VPNs support only unicast routing, whereas many of the enterprise customers that use the service run applications that require IP multicast. This article examines multicastVPN (mVPN), which provides the ability to support IP multicast across MPLS VPNs. Service providers can thus offer IP VPN services that support unicast and multicast applications.