This read-only 64-bit counter tallies the number of Layer 2 Protocol Tunneling transmitted frames that were de-encapsulated on this port during the interval, per the description. Admins use this to verify that L2PT is actively processing tunneled control-protocol frames, like STP, as expected when bridging customer Layer 2 protocols across the provider network. For example, if a customer's spanning-tree domain spanning two sites over this provider link stops converging correctly, an admin would check this counter to confirm L2PT de-encapsulation is actually occurring on this port.