Refer to the exhibit.

In Cisco Unified MPLS, BGP (Border Gateway Protocol) is used to transport labels along with network layer reachability information. RFC 3107 defines BGP/MPLS IP Virtual Private Networks (VPNs) and allows BGP to carry MPLS labels, enhancing scalability and flexibility in MPLS networks.

References

1: Cisco. “Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR).” Link