Which of the following is a characteristic of a P device?

A P device, commonly known in the context of MPLS (Multiprotocol Label Switching), primarily focuses on the efficient handling of packet forwarding within the network. The characteristic that defines P devices is their role in performing label swapping for packets. This function is crucial because it allows P devices to quickly route packets based on the MPLS labels attached to them, instead of relying on more complex routing table lookups that are typically time-consuming.

By utilizing label swapping, P devices can enhance the speed and performance of data transport across the network, as they only need to reference the labels to determine the next hop for the packet. This characteristic is fundamental to the MPLS architecture and contributes to its ability to support various types of traffic and Quality of Service (QoS) requirements effectively.

In contrast, the other options pertain more to the roles of Customer Edge (CE) devices and Provider Edge (PE) devices rather than P devices. For instance, terminating customer connections and providing service access to CE devices are functions associated with PE devices, whereas applying service labels typically occurs at the ingress of the MPLS network, which is the function of the PE devices as well.