The value of tmnxIPsecStaticSASpi specifies the
SPI (Security Parameter Index) used to lookup the instruction to
verify and decrypt the incoming IPsec packets when the value of
tmnxIPsecStaticSADirection is 'inbound'.
The value of tmnxIPsecStaticSASpi specifies the SPI that will be used
in the encoding of the outgoing packets when the value of
tmnxIPsecStaticSADirection is 'outbound'. The remote node can use this
SPI to lookup the instruction to verify and decrypt the packet.
If 'no' SPI is selected, then this static SA cannot be used.
This is an optional object when creating an entry in tmnxIPsecStaticSATable.