This static characteristic indicates the level of security protection.
The security values are architecturally defined to provide continuity
across all networks. Currently, security is encoded as one of the
following seven values:
guardedRadiation - guarded conduit containing the transmission
medium; protected against physical and radiation tapping.
encrypted - link level encryption is provided
unknown - has not been determined
guardedConduit - guarded conduit; protected against physical
tapping
secureConduit - secure conduit, not guarded; e.g. pressurized pipe
undergroundCable - underground cable located in a secure country
publicSwitchedNetwork - public switched network; secure in the
sense that there is no predetermined route that traffic will take
nonSecure - all else, e.g. satellite-connected, located in a nonsecure
country.