Linking multiple networks across MPLS VPN

To complete this recipe, we will be using the Network Intent Composition and VpnService projects.

The scope of the usecase is to enable a MPLS VPN connection across customer sites in a single MPLS domain. Within the domain, MPLS Label is used to isolate traffic between the sites.

The Provider Edge routers (PE) and the Provider routers (P) are managed by OpenDaylight.

In order to create end-to-end VPN connectivity across customer sites, OpenDaylight shall provision MPLS intents to respective PEs and Ps that form the shortest route between the two sites.

Additionally, by adding constraint attributes to intents for protection and failover mechanisms, we can ensure end-to-end connectivity between endpoints to reduce the risk of connectivity failure due to a single link or port down event on a forwarding device:

• Protection constraint: This requires end-to-end connectivity to be protected by providing redundant paths

• Failover constraint: This specifies the type of failover implementation
  • slow-reroute: Uses disjoint path calculation algorithms such as Suurballe to provide alternative end-to-end routes
  • fast-reroute: Uses failure detection features in hardware forwarding devices through OF group table features (future work)

When no constraint is requested by the user, we default to offering end-to-end routes using the Dijkstra shortest path.