module PerfHist-TC-MIB {

    yang-version 1;

    namespace
      "urn:ietf:params:xml:ns:yang:smiv2:PerfHist-TC-MIB";

    prefix PerfHist-TC-MIB;

    import ietf-yang-smiv2 {
      prefix smiv2;
    }
    import ietf-yang-types {
      prefix yang;
    }

    organization
      "IETF AToMMIB and TrunkMIB WGs";

    contact
      "Kaj Tesink
Postal:  Bellcore
	 331 Newman Springs Road
	 Red Bank, NJ 07701
	 USA
Tel:     +1 732 758 5254
Fax:     +1 732 758 2269
E-mail:  kaj@bellcore.com";

    description
      "This MIB Module provides Textual Conventions
to be used by systems supporting 15 minute
based performance history counts.";

    revision "1998-11-07" {
      description
        "[Revision added by libsmi due to a LAST-UPDATED clause.]";
    }

    smiv2:alias "perfHistTCMIB" {
      smiv2:oid "1.3.6.1.2.1.58";
    }

    typedef PerfCurrentCount {
      type yang:gauge32;
      description
        "A counter associated with a
performance measurement in a current 15
minute measurement interval. The value
of this counter starts from zero and is
increased when associated events occur,
until the end of the 15 minute interval.
At that time the value of the counter is
stored in the first 15 minute history
interval, and the CurrentCount is
restarted at zero. In the
case where the agent has no valid data
available for the current interval the
corresponding object instance is not
available and upon a retrieval request
a corresponding error message shall be
returned to indicate that this instance
does not exist (for example, a noSuchName
error for SNMPv1 and a noSuchInstance for
SNMPv2 GET operation).";
    }

    typedef PerfIntervalCount {
      type yang:gauge32;
      description
        "A counter associated with a
performance measurement in a previous
15 minute measurement interval. In the
case where the agent has no valid data
available for a particular interval the
corresponding object instance is not
available and upon a retrieval request
a corresponding error message shall be
returned to indicate that this instance
does not exist (for example, a noSuchName
error for SNMPv1 and a noSuchInstance for
SNMPv2 GET operation).
In a system supporting
a history of n intervals with
IntervalCount(1) and IntervalCount(n) the
most and least recent intervals
respectively, the following applies at
the end of a 15 minute interval:
- discard the value of IntervalCount(n)
- the value of IntervalCount(i) becomes that
  of IntervalCount(i-1) for n >= i > 1
- the value of IntervalCount(1) becomes that
  of CurrentCount
- the TotalCount, if supported, is adjusted.";
    }

    typedef PerfTotalCount {
      type yang:gauge32;
      description
        "A counter associated with a
performance measurements aggregating the
previous valid 15 minute measurement
intervals. (Intervals for which no valid
data was available are not counted)";
    }
  }  // module PerfHist-TC-MIB