The On-Board Management Interface (OBMI) provides an
out-of-band communications channel (in Cisco terms: 
a console port), that is capable of running on various
low-speed to high-speed satellite telemetry busses,
such as the m500 bus.
        
OBMI is similar to SNMP in principle and function, in 
that it allows 'getting' data from or 'setting' 
configurations in a device, however, OBMI is functional
regardless of the software state of the device.  It
must be so, because OBMI is the primary control mechanism
for a device operating in the harsh environment of space.
        
OBMI transports command messages that originate from the
ground to a device in space and transports telemetry 
messages that originate from that device in space to the
ground.
        
The OBMI application is divided into three conceptual layers:
1.  The OBMI application layer which concerns operating system
    subsystems and their associated command and telemetry
    messages.
2.  A FRAMING layer which formats the OBMI messages into
    frames that are suitable for transport over a specific
    spacecraft bus.
3.  The PHY (physical) layer which handles sending and 
    receiving the frames over the physical media.
        
Counts associated with the success or failure of these
various transport layers are reported by this MIB.
        
         GLOSSARY
        
command   :  data that goes from the ground to the device 
             in space
frame     :  OBMI messages are broken into frames to be
             sent by the physical bus or reassembled from
             the bus to be sent to the OBMI subsystem
m500      :  A particular space command/telemetry bus
message   :  fully assembled set of frames that make up
             commands or telemetry. The topmost OBMI 
             layer of the OBMI subsystem operates with
             messages
OBMI      :  On-board Management Interface
telemetry :  data that goes from the device in space to the
             ground
word      :  a collection of bits, sized for the particular
             bus