The software version currently operating in this device.
This object should be in the syntax used by the individual
vendor to identify software versions. Any CM MUST return a
string descriptive of the current software load. For a
CMTS, this object SHOULD contain either a human readable
representation of the vendor specific designation of the
software for the chassis, or of the software for the
control processor. If neither of these is applicable,
this MUST contain an empty string.