This MIB module describes, stores, and reports outage 
related information generated by individual hardware 
and software components comprising a router. They includes 
physical interfaces, logical interfaces, physical 
entities such as chassis, slots, modules, ports, 
power supplies, and fan, software processes 
running on each card, and logical entity, which can be 
defined by outage monitoring program,
which are IOS software for each LC and RP,
router device, and CPU utilization. 

The outage related information comprises entity or 
interface up and down, process start and abnormal 
or normal termination, unusually high CPU utilization
caused, for example, by Denial of Service (DoS) attack,
etc.

The outage related event can be collected by means of 
Cisco's fault manager, Cisco's event manager, and 
syslog messages, etc.

An outage manager maintains the following outage data
for each component.

    1) Accumulated Outage Time (AOT): total outage 
       time of a component from the beginning of 
       the measurement. 

    2) Number of Accumulated Failure (NAF): total 
       number of failure instance from the 
       beginning of the measurement.

    3) Recording Start Time (RST): the date-time 
       that the measurement process began against the object. 
     
Using aforementioned outage data, users can calculate 
and correlate to derive availability information as 
follows: 

    1) Component Availability: the probability 
       that a component will operate when needed. 

       = (1 - (Outage Time / Duration))

    2) DPM (Defects per Million): measure(s) of the 
       defects of the system that have an immediate 
       impact on the end-user. 

       = ([AOTi / (Measurement Interval)] x 10**6)

    3) MTTR(Mean Time To Recovery): expected average 
       time to restore a failed component. 

       = (AOTi / NAFi)

    4) MTBF (Mean Time Between Failure): expected 
       average time between failures of a component.

       = (T2 - RSTi) / NAFi 

    5) MTTF (Mean Time To Failure): the mean time to 
       failure once the device starts working.

       = (MTBFi - MTTRi = (T2 - RSTi - AOTi) / NAFi)


                         measurement 1
                     |<----------------->|
                     |                   |
    System Up @------|-------------------|----> Time
                    RSTi                 T2

    At the beginning RSTi:

	       tmp_AOT = AOTi (from the MIB polling);

    At the end T2:

       Duration = Current Time(T2) - RSTi;
       Outage Time = AOTj - tmp_AOT;