Which of the following describes the responsibilities of a PE in MPLS VPN?

The role of a Provider Edge (PE) router in an MPLS VPN environment is pivotal to the proper functioning of the service. One of the primary responsibilities of a PE router is to direct packets based on the outer label. In an MPLS network, packets are encapsulated with an MPLS header that contains a label, which is used to make forwarding decisions. This label is applied to packets within the MPLS network and is critical for the efficient routing of data through the network.

When packets arrive at a PE router, the router inspects the outer label to determine the appropriate forwarding path based on the predefined label-switched paths (LSPs). This process allows the PE to effectively manage traffic between different VPNs while ensuring that the data remains segregated and secure. Accurately interpreting the outer label is crucial for maintaining the integrity of the data flow within the MPLS architecture, particularly in a multi-tenant environment where multiple customers' data must be handled concurrently.

This role of directing packets using the outer label is what facilitates the scalability and robustness that MPLS VPNs are known for, ensuring smooth and efficient communication across the network.