Description: The current bandwidth consumed.  The measurement unit is
 in megabits per second (1,000,000 bits/second).
 This value gives a reasonable estimate of the amount of
 traffic currently flowing through the switch.

 It is calculated as follows:

 Octets*8 + Frames*(96 + 64)
 ---------------------------
 Measurement Interval * 1,000,000 * 2

Where:
  Measurement Interval is the amount of time over which
  the Octets and Frames were collected, in seconds.

  Measurement Interval is always one second in current
  implementation.

  Octets is the total number of octets transmitted
  or received by all network interfaces, excluding
  framing data but including FCS. This includes octets
  in frames which were partially transmitted or
  received (due to collisions, for example).

  Frames is the total number of frames transmitted
  or received by all network interfaces, including
  frames with errors.

 The number of frames is multiplied by 96 plus 64 in
 order to estimate the delay between each frame for
 Ethernet's IPG and preamble/SFD.

 The '2' in the divisor makes this a forwarding bandwidth
 counter. A frame received on one interface is typically
 forwarded out another interface. In order to avoid double-
 counting this frame's bandwidth, once on the receiving
 interface and once on the transmitting interface, the
 total bandwidth is divided by two.
 Since multicast and broadcast frames can be sent to multiple
 ports, the above is at best a lower bound.