The Nokia PBB implementation offers the capability to use core Ethernet tunnels compliant with ITU-T G.8031 specification to achieve 50 ms resiliency for failures in a native Ethernet backbone. For further information about Ethernet tunnels, see ‟G.8031 Protected Ethernet Tunnels” in the 7450 ESS, 7750 SR, 7950 XRS, and VSR Services Overview Guide.