This object contains the next appropriate value to
be used for mplsTunnelIndex when creating entries
in mplsTunnelTable. If the number of unassigned
entries is exhausted, a retrival operation will
return a value of 0. This object may also return a
value of 0 when the LSR is unable to accept
conceptual row creation, for example, if the
mplsTunnelTable is implemented as read-only. To
obtain the value of mplsTunnelIndex for a new
entry, the manager must first issue a management
protocol retrieval operation to obtain the current
value of this object. The agent should modify the
value to reflect the next unassigned index after
each retrieval operation. After a manager retrieves
a value the agent will determine through its local
policy when this index value will be made available
for reuse.