A tunnel needs to be uniquely identified across
an MPLS network. hwMplsTunnelStatisticsTunnelIndex
uniquely identifies a tunnel on the LSR originating
the tunnel. hwMplsTunnelStatisticsIngressLSRId
uniquely identifies a tunnel across an MPLS network.
The last index hwMplsTunnelStatisticsEgressLSRId is
useful in identifying all instances of a tunnel that
are terminated on the same egress LSR.
The indexes of this table are
hwMplsTunnelStatisticsTunnelIndex,
hwMplsTunnelStatisticsIngressLSRId and
hwMplsTunnelStatisticsEgressLSRId.