The value of the MPLS EXP (experimental) or Traffic Class bits that the SID statistics relate to. Packets received with a MPLS label value equal to the SID's MPLS label and EXP bits equal to the this value should be counted towards the associated ingress statistics. Packets that are forwarded to the destination MPLS label corresponding to the SID should be counted towards this value. In the egress direction, where forwarding follows a SID value that requires PHP at the local node, packets should still be counted towards the egress counters.