The lldpTxDelay indicates the delay (in units
of seconds) between successive LLDP frame transmissions
initiated by value/status changes in the LLDP local systems
MIB. The recommended value for the lldpTxDelay is set by the
following formula:
1 <= lldpTxDelay <= (0.25 * lldpMessageTxInterval)
The default value for lldpTxDelay object is two seconds.
The value of this object must be restored from non-volatile
storage after a re-initialization of the management system.