Description: An index that uniquely identifies an entry in

the olThresh table. The number of entries in olTRThreshTable

is olThreshTotalEntries. A new entry is created when a value is

written to any object within the entry. An entry is removed when

olThreshMode is set to clear(3).

Index 255 references a 'pseudo entry' that allows

the management station to create a new entry without having to

search for a clear entry.

When olThreshMode for entry 255 is set to disable or enable,

if there is no available (clear) entry, then the SNMP set-response will

indicate a bad value error, otherwise the agent does the following:

- set the value of olThreshLastCreatedIndex to the index

of the available entry

- copy the values currently in entry 255 to the available entry

- clear out entry 255.