This parameter can be used to override the
etsysOspfExtCalcMaxDelay when the number of updates to the
Link State Database reaches a threshold value.
-1 Indicates that this threshold is infinite, and hence
the timing of a routing calculation is determined solely by
etsysOspfExtCalcMaxDelay.
0 Indicates that a routing calculation will immediately
follow an update to the database.
1..2147483647
Specifies the threshold number of updates that can be made
to the Link State Database such that any subsequent update
to the database causes a full routing calculation to start
immediately.