Layer 3 VPN over Multiprotocol Label Switching (MPLS) is the most widely deployed MPLS application in Service Provider and self-managed Enterprise networks. The Cisco IOS Software implementation of this architecture (RFC 2547) provides secure control and forwarding planes upon which to build robust VPNs.
Virtual Routing Forwarding instances constructed by Multiprotocol-Border Gateway Protocol (MP-BGP) provide adequate routing separation on a shared multi-service edge. The integration between MP-BGP and MPLS technology allows users to maintain separation between traffic from multiple subscriber networks as the traffic is switched through a single shared core.
Cisco IOS MPLS Layer 3 VPNs enable Service Providers to offer any-to-any connectivity services that can be implemented over either an MPLS or an IP infrastructure.
To meet unique customer requirements, Cisco has also extended MPLS Layer3 VPN support over IP with MPLS VPN over IP. This solution, which supports Layer 3 VPNs for L2TPv3, eliminates the need to implement MPLS in the core.
Service Providers can realize numerous benefits from the MPLS Layer 3 VPN architecture. It enables them to:
- Build scalable, manageable, and secure LAN, MAN, and WAN networks
- Provide precise Service Level Agreements for IP traffic
- Bundle Internet connectivity, Voice over IP, Multicast, and traditional IP services, which are already present in most subscriber networks
- Support remote access technologies (ie: DSL, Dial, IPsec)
- Ease migration from Frame Relay or ATM to Layer 3 VPN services