The carrier-of-carriers VPN can be used to create two-tiered hierarchical VPNs. In a hierarchical VPN, the provider carrier’s VPN is the backbone, or tier-1 VPN, and the customer carrier provides the tier-2 VPN services to its customers.
In a hierarchical VPN environment, each carrier maintains the internal routes of its customers in VRF tables on its PE routers. Routes are learned and maintained as follows:
Figure 108 shows a sample carrier-of-carriers environment in which the customer carrier provides VPN services to its customers.
Figure 108: Carrier-of-Carriers VPN Service
 | Copyright © 2008, Juniper Networks, Inc. All rights reserved. Trademark Notice. | |