The lifetime given to SA cache entries when created or
refreshed. This is the [SA-State-Period] in the MSDP spec.
A value of 0 means no SA caching is done by this MSDP
speaker.
Changes to this object should be stored to non-volatile
memory.
This object does not measure time per se; instead, it is the
delta from the time at which an SA message is received at
which it should be expired if not refreshed. (i.e., it is
the value of cMsdpSACacheExpiryTime immediately after
receiving an SA message applying to that row.) As such,
TimeInterval would be a more appropriate SYNTAX; it remains
TimeTicks for backwards compatability.