Description: 
This module contains the definitions for statistics collected for
OAM Performance Monitoring.  The definition and requirement for
these statistics are found in GR-1248-CORE. In addition, Cell
Loss Ratio has been added as part of the Newbridge extension.

This MIB module contains the following tables:
  OAM PM 15 Minute Current Table
  OAM PM 15 Minute Interval Table
  OAM PM 24 Hour Current Table
  OAM PM 24 Hour Interval Table

These tables are heavily influenced by the definition of VPL/VCL
described in rfc1695. The number of intervals supported is dependent upon
resource availibility on any given product, but should nominally be 32 
for 15 Minute intervals and 2 for 24 Hour intervals. To avoid building 
in massive amounts of storage, some products may adopt a bulk 
collection scheme.

Intervals:
  Statistics on the performance of VPL/VCLs are collected over a
  historical stratum of up to a maximum of M intervals. The value of M
  is a function of a product's storage capability. For example, on the
  36170 product, M = 32 for 15 Minute interval.

  The 15 Minute intervals are aligned to the quarter of one hour of a 
  wall clock. The current interval spans back to the last 15 minute 
  tick on the wall clock. Continuing along the timeline from that point 
  is the most recently completed interval and has an index of 1. The 
  previous interval has an index of 2 and so on. Note that the oldest 
  interval may be incomplete since the statistic collection may have 
  been enabled offset to the quarter or one hour tick.

             t
             0          -1i         -2i         -3i
  ===========|===========|===========|===========|===========
    current      N = 1       N = 2       N = 3       N = 4    ... N = M
    interval

Performance Monitoring Demarcation Values:
As defined in GR-1248-CORE, three demarcation values are defined to
evaluate the condition of a PM cell block. These are M errored, M lost
and M misinserted. These values are configurable on a system-wide basis.
Where applicable, the definition of a statistics object in this module
will refer to one or more of these values.