RFC 1224 (rfc1224) - Page 2 of 22

Techniques for managing asynchronously generated alerts

RFC 1224        Managing Asynchronously Generated Alerts        May 1991


   5. Closed Loop "Feedback" Alert Reporting with a "Pin" Sliding
      Window Limit...................................................  6
   5.1 Use of Feedback...............................................  7
   5.1.1 Example.....................................................  8
   5.2 Notes on Feedback/Pin usage...................................  8
   6. Polled, Logged Alerts..........................................  9
   6.1 Use of Polled, Logged Alerts.................................. 10
   6.1.1 Example..................................................... 12
   6.2 Notes on Polled, Logged Alerts................................ 12
   7. Compatibility with SNMP and CMOT .............................. 14
   7.1 Closed Loop Feedback Alert Reporting.......................... 14
   7.1.1 Use of Feedback with SNMP................................... 14
   7.1.2 Use of Feedback with CMOT................................... 14
   7.2 Polled, Logged Alerts......................................... 14
   7.2.1 Use of Polled, Logged Alerts with SNMP...................... 14
   7.2.2 Use of Polled, Logged Alerts with CMOT...................... 15
   8. Notes on Multiple Manager Environments......................... 15
   9. Summary........................................................ 16
   10. References.................................................... 16
   11. Acknowledgements.............................................. 17
   Appendix A.  Example of polling costs............................. 17
   Appendix B.  MIB object definitions............................... 19
   Security Considerations........................................... 22
   Author's Address.................................................. 22

1.  Introduction

   This memo defines mechanisms to prevent a remotely managed entity
   from burdening a manager or network with an unexpected amount of
   network management information, and to ensure delivery of "important"
   information.  The focus is on controlling the flow of asynchronously
   generated information, and not how the information is generated.
   Mechanisms for generating and controlling the generation of
   asynchronous information may involve protocol specific issues.

   There are two understood mechanisms for transferring network
   management information from a managed entity to a manager: request-
   response driven polling, and the unsolicited sending of "alerts".
   Alerts are defined as any management information delivered to a
   manager that is not the result of a specific query.  Advantages and
   disadvantages exist within each method.  They are detailed in section
   2 below.

   Alerts in a failing system can be generated so rapidly that they
   adversely impact functioning resources.  They may also fail to be
   delivered, and critical information maybe lost.  Methods are needed
   both to limit the volume of alert transmission and to assist in
   delivering a minimum amount of information to a manager.



Steinberg