rfc1109.txt

<VC++网络游戏建摸与实现>源代码


RFC 1109                  Internet Management                August 1989


APPLICATION PROGRAMMING INTERFACE (API)

   It was generally agreed that the actual network management tools
   available to operators, rather than the specifics of the protocols
   supporting the tools, would be the determining factor in the
   effectiveness of any Internet network management system.  A brief
   report was offered and discussion ensued on the possibility of
   creating a common application programming interface that could be
   used independent of the specific protocol (CMOT, SNMP, CMIP or
   proprietary) used to transport queries and commands.

   It was acknowledged that the present service interfaces of both SNMP
   and CMIS have limitations (e.g., neither has any sense of time other
   than "now"; this makes it impossible to express queries for
   historical information, or to issue command requests of the form: Do
   X at device Y, beginning in 30 minutes).  These limitations hinder
   both SNMP and CMOT from directly offering a comprehensive API for
   network management applications.

   Although some positive sentiment was expressed for defining a kind of
   "super SMI" metalanguage to aid in the the definition of a general
   API, it was not clear whether the current crop of supporting
   protocols had sufficient semantic commonality to be used in this way.
   The matter remains open for investigation.

NIST ACTIVITIES

   The Ad Hoc Review had the benefit of representatives from NIST who
   are active in the network management area.  It was reported that the
   major focus at present is at layers 3 and 4 where objects are being
   defined in accordance with "templates" provided by ISO's SC21.  IEEE
   802 is also pursuing the definition of MIB objects, though not with
   the benefit of the same templates now in use by the NIST NMSIG.  The
   layers above transport are just beginning to receive attention.

   It was observed that the Internet SMI is not quite a subset of the
   ISO CMIS SMI.  The Internet variable naming conventions are a little
   different and some functionality may vary.  There was some
   uncertainty about the treatment of gauges in the Internet SMI and the
   corresponding OSI SMI.  [L. Steinberg reported, subsequent to the
   meeting, that gauges latch and counters roll over in the OSI SMI, as
   they appear to do in the Internet SMI - VGC].

   The general sense of this portion of the discussion was that a
   considerable amount of activity is underway with the sponsorship of
   NIST and that this work is relevant to the Internet community,
   particularly as the time approaches in which coexistence of the OSI
   protocol suite with the existing Internet protocols is the norm.



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RFC 1109                  Internet Management                August 1989


CONCLUSIONS AND RECOMMENDATIONS

   The assembled attendees came to the conclusions enumerated below and
   recommends to the IAB that actions be taken which are consistent with
   these conclusions:

      1. The Internet will exist in a pluralistic protocol stack
         environment and the need to coexist will persist.

      2. Expansion of the common MIB has been impeded by an inability to
         agree on a common, extended SMI.

      3. The Internet community must not ignore the work of other groups
         in the network management area, while at the same time, coping
         with the current operational needs of the Internet (and
         internet) communities.

      4. Until we can gain operational experience with OSI network
         management tools (e.g., with CMIP on TCP or on OSI), we cannot
         specify a plan for coexistence with and transition to use of
         the OSI-based protocols in the Internet.

   Therefore:

      (a) We want to foster an environment for real CMOT/CMIP use.

      (b) We should take action as needed to extend SNMP for operational
          reasons.

      (c) We must preserve the utility of the first agreed common MIB
          (RFC 1066).

      (d) We should develop, separately, experimental and enterprise MIB
          variables and seek opportunity for placing these in the common
          MIB.

      (e) In a coexisting environment, we will need to access the same
          set of variables (e.g., in a given gateway or router) by means
          of more than one protocol (e.g., SNMP, CMIP/TCP, CMIP/CLNP,
          etc.).

   It is recommended to the IAB that the network management efforts
   using SNMP and CMOT be allowed independently to explore new variables
   and potentially non-overlapping SMI definitions for the next 12
   months so as to foster operational deployment and experience with
   these network management tools.  In essence, it is recommended that
   the binding of SNMP and CMOT to a common MIB/SMI be relaxed for this
   period of exploration.  Variables which are NOT supportable in common



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RFC 1109                  Internet Management                August 1989


   by both protocols should be defined in the experimental or private
   parts of the MIB definition space.  Obviously, care should be taken
   to achieve agreement within each respective working group on any
   variables added to the distinct SNMP and CMOT experimental spaces.

   Specifically, the CMOT working group should extend its MIB and SMI
   definitions in the direction of the OSI/NIST specifications so as to
   bring CMOT into closer alignment with the OSI CMIS design.

   During this period of experimentation, it is strongly recommended
   that the IAB seek opportunities to encourage the introduction of
   Internet elements which use the OSI protocols into the Internet
   environment.  Such OSI-based elements offer an opportunity to obtain
   operational experience with monitoring and management support by way
   of the CMIP and CMOT protocols.  It is anticipated that network
   management systems based on the OSI Common Management Information
   Service (CMIS) will be developed which use CMIP or CMOT, as
   appropriate, to manage various elements in the Internet.

   It is also recommended that the IAB engage in an active liaison
   effort with the NIST, focusing especially on the question of
   coexistence of the Internet protocols with OSI protocols.  If at all
   possible, joint experimental or test-bed efforts should be initiated
   to identify means for supporting this coexistence.

   As necessary, the Internet Engineering Task Force should be directed
   to restructure its network management efforts both to support the
   need for MIB/SMI exploration by the SNMP and CMOT groups and to
   strengthen links between the IETF efforts and those of NIST.

   Finally, it is recommended that the Ad Hoc Review Group be reconvened
   at 6 month intervals to review status and to determine whether
   opportunities for expanding the common MIB/SMI are available.

REFERENCES

   1.  Cerf, V., "IAB Recommendations for the Development of Internet
       Network Management Standards", RFC 1052, NRI, April 1988.

   2.  Rose, M., and K. McCloghrie, "Structure and Identification of
       Management Information for TCP/IP-based internets", RFC 1065,
       TWG, August 1988.

   3.  McCloghrie, K., and M. Rose, "Management Information Base for
       Network Management of TCP/IP-based internets", RFC 1066, TWG,
       August 1988.

   4.  Schoffstall, M., C. Davin, M. Fedor, and J. Case, "SNMP over



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RFC 1109                  Internet Management                August 1989


       Ethernet", RFC 1089, Rensselaer Polytechnic Institute, MIT
       Laboratory for Computer Science, NYSERNet, Inc., and University
       of Tennessee at Knoxville, February 1989.

   5.  Warrier, U., and L. Besaw, "Common  Management Information
       Services and Protocol over TCP/IP (CMOT)", RFC 1095, Unisys
       Corporation, and Hewlett-Packard, April 1989.

   6.  Case, J., M. Fedor, M. Schoffstall, and C. Davin, "Simple Network
       Management Protocol (SNMP)", RFC 1098, University of Tennessee at
       Knoxville, NYSERNet, Inc., Rensselaer Polytechnic Institute, and
       MIT Laboratory for Computer Science, April 1989.

Appendix A - Ad Hoc Net Management Review Attendance List

   Amatzia Ben-Artzi   3Com
   Paul Brusil         MITRE
   John Burruss        Wellfleet Communications
   Jeff Case           University of Tennessee at Knoxville
   Vint Cerf           National Research Initiatives
   Ralph Droms         Bucknell University (on sabbatical at NRI)
   Mark Fedor          NYSERNet
   Phill Gross         National Research Initiatives
   Lee LaBarre         MITRE
   Bruce Laird         Bolt Beranek and Newman
   Gary Malkin         Proteon
   Keith McCloghrie    Wollongong
   Craig Partridge     Bolt Beranek and Newman
   Marshall Rose       NYSERNet
   Greg Satz           cisco Systems
   Marty Schoffstall   NYSERNet
   Louis Steinberg     IBM
   Dan Stokesberry     NIST
   Unni Warrier        Netlabs

Author's Address

   Vinton G. Cerf
   Corporation for National Research Initiatives
   1895 Preston White Drive, Suite 100
   Reston, VA 22091

   Phone: [phone]

   EMail: [e-mail]






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