Carrier-of-Carriers VPNs
The customer of a VPN service provider might be a service provider for the end customer. The following are the two main types of carrier-of-carriers VPNs (as described in BGP/MPLS VPNs):
- Internet Service Provider as the Customer—The VPN customer is an ISP that uses the VPN service provider's network to connect its geographically disparate regional networks. The customer does not have to configure MPLS within its regional networks.
- VPN Service Provider as the Customer—The VPN customer is itself a VPN service provider offering VPN service to its customers. The carrier-of-carriers VPN service customer relies on the backbone VPN service provider for intersite connectivity. The customer VPN service provider is required to run MPLS within its regional networks.
Figure 43 illustrates the network architecture used for a carrier-of-carriers VPN service.
