Re: Expression MIB

Hi,
  The following is the Expression MIB implementation experience at
Cyber Solutions.

   Glenn

>>=================================================
>>
>>Implementat Survey for RFC 2982,
>>Distributed Management Expression MIB
>>
>>
>>Implementation Source:          Cyber Solutions Inc. 
>>Management Application / Agent: Application and Agent
>>Module: DISMAN-EXPRESSION-MIB
>>
>>GROUPs:
>>dismanExpressionResourceGroup (y/n): n
>>dismanExpressionDefinitionGroup (y/n): y
>>dismanExpressionValueGroup (y,n): y
>>
>>OBJECTs:
>>expResourceDeltaMinimum full range supported (y/n): n
>>expObjectSampleType deltas supported (y/n): y
>>expObjectIDWildcard wildcard supported (y/n): n
>>expObjectDiscontinuityIDWildcard wildcard supported (y/n): n
>>expObjectConditionalWildcard deltas/wildcards supported (y/n): n
>>
>>
>>Deployment / Operational Experience:
  The DISMAN-EXPRESSION-MIB is deployed on our passive sensors
  (CpMonitor). There is generic proprietary MIB (CpMonitorMIB)
  that is supported on these sensors that covers a very wide
  range of protocol based statistics,
     [VLAN, IP,MAC] wise,
        [IPv4,IPv6,Other] stats,
        [UDP,TCP.ICMP,Other] stats
        [Port] stats
  Three type of stats are served - the Min, Max and Average. The
  Max is taken by considering the deltas of the statistic over a
  small interval (msecs) in the polling window.

  That is a rich source of information but sending it all to the
  manager does ot make sense and is bandwidth/resource expensive.
  We use the DISMAN-EXPRESSION-MIB to build higher level
  information objects to cater to the needs of the Network Manager.

  We have a generic Management Application (ApMan) module of our
  network management platform (NetSkate Visualizer) that has a
  simple GUI that interfaces with the agent and allows a user to
  generate the expressions for the higher level information objects.
  The Network Manager uses these higher information objects for simple
  matters like statistics generation, resource management, fault
  detection, and security management.

  We have also built an aggregation mechanism which may be considered
  as an extension of the DISMAN-EXPRESSION-MIB. It basically allows the
  concatenation of MO instance values. This has proven to be very
  effective in routine polling of a large number of MOs. This cuts
  down the overhead of OIDs in the SNMP 'get' and 'response' PDUs.

  Computer resource consumption due to delta's is not a major
  concern on these sensors.

  The net-snmp code base is used for the implementation.
>>
>>Comments:
>>
 1. The MIB is nicely done - but there are places that need more
    clarity. Particularly the definitions of the operators and
    operations.
 2. The wild-carding provides great power but its implementation
    was found to be complex.
 3. I would recommend the addition of the MO-instance value
    concatenation operator. It has immediate and wide-spread
    application.