An NG MVPN is a new framework designed to transmit IP multicast traffic across a BGP/MPLS IP VPN. An NG MVPN uses BGP to transmit signaling information, and uses PIM-SM, PIM-SSM, P2MP TE, or mLDP to transmit data. The NG MVPN enables unicast and multicast services to be delivered using the same VPN architecture.
BGP/MPLS IP VPNs are widely deployed worldwide as they provide excellent reliability and security. In addition, IP multicast is gaining increasing popularity among service providers as it provides highly efficient P2MP traffic transmission. Rapidly developing multicast applications, such as IPTV, video conference, and distance education, impose increasing requirements on network reliability, security, and efficiency. As a result, service providers' demand for delivering multicast services over BGP/MPLS IP VPNs is also increasing. In this context, the MVPN solution is developed. The MVPN technology, when applied to a BGP/MPLS IP VPN, can transmit VPN multicast traffic to remote VPN sites across the public network.
Rosen MVPNs establish MDTs using PIM to transmit VPN multicast protocol and data packets, but have the following limitations:
VPN multicast protocol and data packets must be transmitted using the MDT. This means that the multicast function must be enabled on the public network, complicating network deployment.
The public network uses GRE for packet encapsulation during multicast data transmission and cannot leverage the MPLS advantages of existing BGP/MPLS IP VPNs, such as high reliability, QoS guarantee, and TE bandwidth reservation.
NG MVPNs, which have made some improvements over Rosen MVPNs, have the following characteristics:
The public network uses BGP to transmit VPN multicast protocol packets and routing information. Therefore, no multicast protocol needs to be deployed on the public network, simplifying network deployment and maintenance.
The public network uses the mature label-based forwarding and tunnel protection techniques of MPLS, improving multicast service quality and reliability.