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