This object identifies the outgoing branch from this LSR
towards the destination represented by this table entry. It
must be a unique identifier within the scope of this tunnel.
If MPLS-LSR-STD-MIB is implemented, this object should
contain an index into mplsOutSegmentTable.
If MPLS-LSR-STD-MIB is not implemented, the LSR should
assign a unique value to each branch of the tunnel.
The value of this object is also used as an index into
cmplsTeP2mpTunnelBranchPerfTable.