RFC1449

From RFC-Wiki
      Network Working Group                                  J. Case
      Request for Comments: 1449                 SNMP Research, Inc.
                                                       K. McCloghrie
                                                  Hughes LAN Systems
                                                             M. Rose
                                        Dover Beach Consulting, Inc.
                                                       S. Waldbusser
                                          Carnegie Mellon University
                                                          April 1993
                            Transport Mappings
                           for version 2 of the
               Simple Network Management Protocol (SNMPv2)
      Status of this Memo
      This RFC specifes an IAB standards track protocol for the
      Internet community, and requests discussion and suggestions
      for improvements.  Please refer to the current edition of the
      "IAB Official Protocol Standards" for the standardization
      state and status of this protocol.  Distribution of this memo
      is unlimited.
      Table of Contents
      Case, McCloghrie, Rose & Waldbusser                   [Page i]
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      1.  Introduction
      A network management system contains: several (potentially
      many) nodes, each with a processing entity, termed an agent,
      which has access to management instrumentation; at least one
      management station; and, a management protocol, used to convey
      management information between the agents and management
      stations.  Operations of the protocol are carried out under an
      administrative framework which defines both authentication and
      authorization policies.
      Network management stations execute management applications
      which monitor and control network elements.  Network elements
      are devices such as hosts, routers, terminal servers, etc.,
      which are monitored and controlled through access to their
      management information.
      The management protocol, version 2 of the Simple Network
      Management Protocol [1], may be used over a variety of
      protocol suites.  It is the purpose of this document to define
      how the SNMPv2 maps onto an initial set of transport domains.
      Other mappings may be defined in the future.
      Although several mappings are defined, the mapping onto UDP is
      the preferred mapping.  As such, to provide for the greatest
      level of interoperability, systems which choose to deploy
      other mappings should also provide for proxy service to the
      UDP mapping.
      1.1.  A Note on Terminology
      For the purpose of exposition, the original Internet-standard
      Network Management Framework, as described in RFCs 1155, 1157,
      and 1212, is termed the SNMP version 1 framework (SNMPv1).
      The current framework is termed the SNMP version 2 framework
      (SNMPv2).
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      2.  Definitions
      SNMPv2-TM DEFINITIONS ::= BEGIN
      IMPORTS
          snmpDomains, snmpProxys
              FROM SNMPv2-SMI
          TEXTUAL-CONVENTION
              FROM SNMPv2-TC;
      -- SNMPv2 over UDP
      snmpUDPDomain  OBJECT IDENTIFIER ::= { snmpDomains 1 }
      -- for a SnmpUDPAddress of length 6:
      --
      -- octets   contents        encoding
      --  1-4     IP-address      network-byte order
      --  5-6     UDP-port        network-byte order
      --
      SnmpUDPAddress ::= TEXTUAL-CONVENTION
          DISPLAY-HINT "1d.1d.1d.1d/2d"
          STATUS       current
          DESCRIPTION
                  "Represents a UDP address."
          SYNTAX       OCTET STRING (SIZE (6))
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      -- SNMPv2 over OSI
      snmpCLNSDomain OBJECT IDENTIFIER ::= { snmpDomains 2 }
      snmpCONSDomain OBJECT IDENTIFIER ::= { snmpDomains 3 }
      -- for a SnmpOSIAddress of length m:
      --
      -- octets   contents            encoding
      --    1     length of NSAP      "n" as an unsigned-integer
      --                                (either 0 or from 3 to 20)
      -- 2..(n+1) NSAP                concrete binary representation
      -- (n+2)..m TSEL                string of (up to 64) octets
      --
      SnmpOSIAddress ::= TEXTUAL-CONVENTION
          DISPLAY-HINT "*1x:/1x:"
          STATUS       current
          DESCRIPTION
                  "Represents an OSI transport-address."
          SYNTAX       OCTET STRING (SIZE (1 | 4..85))
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      -- SNMPv2 over DDP
      snmpDDPDomain  OBJECT IDENTIFIER ::= { snmpDomains 4 }
      -- for a SnmpNBPAddress of length m:
      --
      --    octets      contents         encoding
      --       1        length of object "n" as an unsigned integer
      --     2..(n+1)   object           string of (up to 32) octets
      --      n+2       length of type   "p" as an unsigned integer
      -- (n+3)..(n+2+p) type             string of (up to 32) octets
      --     n+3+p      length of zone   "q" as an unsigned integer
      -- (n+4+p)..m     zone             string of (up to 32) octets
      --
      -- for comparison purposes, strings are case-insensitive
      --
      -- all strings may contain any octet other than 255 (hex ff)
      --
      SnmpNBPAddress ::= TEXTUAL-CONVENTION
          STATUS       current
          DESCRIPTION
                  "Represents an NBP name."
          SYNTAX       OCTET STRING (SIZE (3..99))
      -- SNMPv2 over IPX
      snmpIPXDomain  OBJECT IDENTIFIER ::= { snmpDomains 5 }
      -- for a SnmpIPXAddress of length 12:
      --
      -- octets   contents            encoding
      --  1-4     network-number      network-byte order
      --  5-10    physical-address    network-byte order
      -- 11-12    socket-number       network-byte order
      --
      SnmpIPXAddress ::= TEXTUAL-CONVENTION
          DISPLAY-HINT "4x.1x:1x:1x:1x:1x:1x.2d"
          STATUS       current
          DESCRIPTION
                  "Represents an IPX address."
          SYNTAX       OCTET STRING (SIZE (12))
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      -- for proxy to community-based SNMPv1 (RFC 1157)
      rfc1157Proxy   OBJECT IDENTIFIER ::= { snmpProxys 1 }
      -- uses SnmpUDPAddress
      rfc1157Domain  OBJECT IDENTIFIER ::= { rfc1157Proxy 1 }
      -- the community-based noAuth
      rfc1157noAuth  OBJECT IDENTIFIER ::= { rfc1157Proxy 2 }
      END
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      3.  SNMPv2 over UDP
      This is the preferred transport mapping.
      3.1.  Serialization
      Each instance of a message is serialized onto a single UDP[2]
      datagram, using the algorithm specified in Section 8.
      3.2.  Well-known Values
      Although the partyTable gives transport addressing information
      for an SNMPv2 party, it is suggested that administrators
      configure their SNMPv2 entities acting in an agent role to
      listen on UDP port 161.  Further, it is suggested that
      notification sinks be configured to listen on UDP port 162.
      The partyTable also lists the maximum message size which a
      SNMPv2 party is willing to accept.  This value must be at
      least 484 octets.  Implementation of larger values is
      encouraged whenever possible.
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      4.  SNMPv2 over OSI
      This is an optional transport mapping.
      4.1.  Serialization
      Each instance of a message is serialized onto a single TSDU
      [3,4] for the OSI Connectionless-mode Transport Service
      (CLTS), using the algorithm specified in Section 8.
      4.2.  Well-known Values
      Although the partyTable gives transport addressing information
      for an SNMPv2 party, it is suggested that administrators
      configure their SNMPv2 entities acting in an agent role to
      listen on transport selector "snmp-l" (which consists of six
      ASCII characters), when using a CL-mode network service to
      realize the CLTS.  Further, it is suggested that notification
      sinks be configured to listen on transport selector "snmpt-l"
      (which consists of seven ASCII characters) when using a CL-
      mode network service to realize the CLTS.  Similarly, when
      using a CO-mode network service to realize the CLTS, the
      suggested transport selectors are "snmp-o"  and "snmpt-o", for
      agent and notification sink, respectively.
      The partyTable also lists the maximum message size which a
      SNMPv2 party is willing to accept.  This value must be at
      least 484 octets.  Implementation of larger values is
      encouraged whenever possible.
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      5.  SNMPv2 over DDP
      This is an optional transport mapping.
      5.1.  Serialization
      Each instance of a message is serialized onto a single DDP
      datagram [5], using the algorithm specified in Section 8.
      5.2.  Well-known Values
      SNMPv2 messages are sent using DDP protocol type 8.  SNMPv2
      entities acting in an agent role listens on DDP socket number
      8, whilst notification sinks listen on DDP socket number 9.
      Although the partyTable gives transport addressing information
      for an SNMPv2 party, administrators must configure their
      SNMPv2 entities acting in an agent role to use NBP type "SNMP
      Agent" (which consists of ten ASCII characters), whilst
      notification sinks must be configured to use NBP type "SNMP
      Trap Handler" (which consists of seventeen ASCII characters).
      The NBP name for agents and notification sinks should be
      stable - NBP names should not change any more often than the
      IP address of a typical TCP/IP node.  It is suggested that the
      NBP name be stored in some form of stable storage.
      The partyTable also lists the maximum message size which a
      SNMPv2 party is willing to accept.  This value must be at
      least 484 octets.  Implementation of larger values is
      encouraged whenever possible.
      5.3.  Discussion of AppleTalk Addressing
      The AppleTalk protocol suite has certain features not manifest
      in the TCP/IP suite.  AppleTalk's naming strategy and the
      dynamic nature of address assignment can cause problems for
      SNMPv2 entities that wish to manage AppleTalk networks.
      TCP/IP nodes have an associated IP address which distinguishes
      each from the other.  In contrast, AppleTalk nodes generally
      have no such characteristic.  The network-level address, while
      often relatively stable, can change at every reboot (or more
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      frequently).
      Thus, when SNMPv2 is mapped over DDP, nodes are identified by
      a "name", rather than by an "address".  Hence, all AppleTalk
      nodes that implement this mapping are required to respond to
      NBP lookups and confirms (e.g., implement the NBP protocol
      stub), which guarantees that a mapping from NBP name to DDP
      address will be possible.
      In determining the SNMP identity to register for an SNMPv2
      entity, it is suggested that the SNMP identity be a name which
      is associated with other network services offered by the
      machine.
      NBP lookups, which are used to map NBP names into DDP
      addresses, can cause large amounts of network traffic as well
      as consume CPU resources.  It is also the case that the
      ability to perform an NBP lookup is sensitive to certain
      network disruptions (such as zone table inconsistencies) which
      would not prevent direct AppleTalk communications between two
      SNMPv2 entities.
      Thus, it is recommended that NBP lookups be used infrequently,
      primarily to create a cache of name-to-address mappings.
      These cached mappings should then be used for any further SNMP
      traffic.  It is recommended that SNMPv2 entities acting in a
      manager role should maintain this cache between reboots.  This
      caching can help minimize network traffic, reduce CPU load on
      the network, and allow for (some amount of) network trouble
      shooting when the basic name-to-address translation mechanism
      is broken.
      5.3.1.  How to Acquire NBP names
      An SNMPv2 entity acting in a manager role may have a pre-
      configured list of names of "known" SNMPv2 entities acting in
      an agent role.  Similarly, an SNMPv2 entity acting in a
      manager role might interact with an operator.  Finally, an
      SNMPv2 entity acting in a manager role might communicate with
      all SNMPv2 entities acting in an agent role in a set of zones
      or networks.
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      5.3.2.  When to Turn NBP names into DDP addresses
      When an SNMPv2 entity uses a cache entry to address an SNMP
      packet, it should attempt to confirm the validity mapping, if
      the mapping hasn't been confirmed within the last T1 seconds.
      This cache entry lifetime, T1, has a minimum, default value of
      60 seconds, and should be configurable.
      An SNMPv2 entity acting in a manager role may decide to prime
      its cache of names prior to actually communicating with
      another SNMPv2 entity.  In general, it is expected that such
      an entity may want to keep certain mappings "more current"
      than other mappings, e.g., those nodes which represent the
      network infrastructure (e.g., routers) may be deemed "more
      important".
      Note that an SNMPv2 entity acting in a manager role should not
      prime its entire cache upon initialization - rather, it should
      attempt resolutions over an extended period of time (perhaps
      in some pre-determined or configured priority order).  Each of
      these resolutions might, in fact, be a wildcard lookup in a
      given zone.
      An SNMPv2 entity acting in an agent role must never prime its
      cache.  Such an entity should do NBP lookups (or confirms)
      only when it needs to send an SNMP trap.  When generating a
      response, such an entity does not need to confirm a cache
      entry.
      5.3.3.  How to Turn NBP names into DDP addresses
      If the only piece of information available is the NBP name,
      then an NBP lookup should be performed to turn that name into
      a DDP address.  However, if there is a piece of stale
      information, it can be used as a hint to perform an NBP
      confirm (which sends a unicast to the network address which is
      presumed to be the target of the name lookup) to see if the
      stale information is, in fact, still valid.
      An NBP name to DDP address mapping can also be confirmed
      implicitly using only SNMP transactions.  For example, an
      SNMPv2 entity acting in a manager role issuing a retrieval
      operation could also retrieve the relevant objects from the
      NBP group [6] for the SNMPv2 entity acting in an agent role.
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      This information can then be correlated with the source DDP
      address of the response.
      5.3.4.  What if NBP is broken
      Under some circumstances, there may be connectivity between
      two SNMPv2 entities, but the NBP mapping machinery may be
      broken, e.g.,
      o    the NBP FwdReq (forward NBP lookup onto local attached
           network) mechanism might be broken at a router on the
           other entity's network; or,
      o    the NBP BrRq (NBP broadcast request) mechanism might be
           broken at a router on the entity's own network; or,
      o    NBP might be broken on the other entity's node.
      An SNMPv2 entity acting in a manager role which is dedicated
      to AppleTalk management might choose to alleviate some of
      these failures by directly implementing the router portion of
      NBP.  For example, such an entity might already know all the
      zones on the AppleTalk internet and the networks on which each
      zone appears.  Given an NBP lookup which fails, the entity
      could send an NBP FwdReq to the network in which the agent was
      last located.  If that failed, the station could then send an
      NBP LkUp (NBP lookup packet) as a directed (DDP) multicast to
      each network number on that network.  Of the above (single)
      failures, this combined approach will solve the case where
      either the local router's BrRq-to-FwdReq mechanism is broken
      or the remote router's FwdReq-to-LkUp mechanism is broken.
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      6.  SNMPv2 over IPX
      This is an optional transport mapping.
      6.1.  Serialization
      Each instance of a message is serialized onto a single IPX
      datagram [7], using the algorithm specified in Section 8.
      6.2.  Well-known Values
      SNMPv2 messages are sent using IPX packet type 4 (i.e., Packet
      Exchange Packet).
      Although the partyTable gives transport addressing information
      for an SNMPv2 party, it is suggested that administrators
      configure their SNMPv2 entities acting in an agent role to
      listen on IPX socket 36879 (900f hexadecimal).  Further, it is
      suggested that notification sinks be configured to listen on
      IPX socket 36880 (9010 hexadecimal)
      The partyTable also lists the maximum message size which a
      SNMPv2 party is willing to accept.  This value must be at
      least 546 octets.  Implementation of larger values is
      encouraged whenever possible.
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      7.  Proxy to SNMPv1
      In order to provide proxy to community-based SNMP [8], some
      definitions are necessary for both transport domains and
      authentication protocols.
      7.1.  Transport Domain: rfc1157Domain
      The transport domain, rfc1157Domain, indicates the transport
      mapping for community-based SNMP messages defined in RFC 1157.
      When a party's transport domain (partyTDomain) is
      rfc1157Domain:
      (1)  the party's transport address (partyTAddress) shall be 6
           octets long, the initial 4 octets containing the IP-
           address in network-byte order, and the last two octets
           containing the UDP port in network-byte order; and,
      (2)  the party's authentication protocol (partyAuthProtocol)
           shall be rfc1157noAuth.
      When a proxy relationship identifies a proxy destination party
      which has rfc1157Domain as its transport domain:
      (1)  the proxy source party (contextSrcPartyIndex) and proxy
           context (contextProxyContext) components of the proxy
           relationship are irrelevant; and,
      (2)  Section 3.1 of [9] specifies the behavior of the proxy
           agent.
      7.2.  Authentication Algorithm: rfc1157noAuth
      A party's authentication protocol (partyAuthProtocol)
      specifies the protocol and mechanism by which the party
      authenticates the integrity and origin of the SNMPv1 or SNMPv2
      PDUs it generates.  When a party's authentication protocol is
      rfc1157noAuth:
      (1)  the party's public authentication key (partyAuthPublic),
           clock (partyAuthClock), and lifetime (partyAuthLifetime)
           are irrelevant; and,
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      (2)  the party's private authentication key
           (partySecretsAuthPrivate) shall be used as the 1157
           community for the proxy destination, and shall be at
           least one octet in length.  (No maximum length is
           specified.)
      Note that when setting the party's private authentication key,
      the exclusive-OR semantics specified in [10] still apply.
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      8.  Serialization using the Basic Encoding Rules
      When the Basic Encoding Rules [11] are used for serialization:
      (1)  When encoding the length field, only the definite form is
           used; use of the indefinite form encoding is prohibited.
           Note that when using the definite-long form, it is
           permissible to use more than the minimum number of length
           octets necessary to encode the length field.
      (2)  When encoding the value field, the primitive form shall
           be used for all simple types, i.e., INTEGER, OCTET
           STRING, OBJECT IDENTIFIER, and BIT STRING (either
           IMPLICIT or explicit).  The constructed form of encoding
           shall be used only for structured types, i.e., a SEQUENCE
           or an IMPLICIT SEQUENCE.
      (3)  When a BIT STRING is serialized, all named-bits are
           transferred regardless of their truth-value.  Further, if
           the number of named-bits is not an integral multiple of
           eight, then the fewest number of additional zero-valued
           bits are transferred so that an integral multiple of
           eight bits is transferred.
      These restrictions apply to all aspects of ASN.1 encoding,
      including the message wrappers, protocol data units, and the
      data objects they contain.
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      8.1.  Usage Example
      As an example of applying the Basic Encoding Rules, suppose
      one wanted to encode an instance of the GetBulkRequest-PDU
      [1]:
           [5] IMPLICIT SEQUENCE {
                   request-id      1414684022,
                   non-repeaters   1,
                   max-repetitions 2,
                   variable-bindings {
                       { name sysUpTime,
                         value { unspecified NULL } },
                       { name ipNetToMediaPhysAddress,
                         value { unspecified NULL } },
                       { name ipNetToMediaType,
                         value { unspecified NULL } }
                   }
               }
      Applying the BER, this would be encoded (in hexadecimal) as:
      [5] IMPLICIT SEQUENCE          a5 82 00 39
          INTEGER                    02 04 52 54 5d 76
          INTEGER                    02 01 01
          INTEGER                    02 01 02
          SEQUENCE                   30 2b
              SEQUENCE               30 0b
                  OBJECT IDENTIFIER  06 07 2b 06 01 02 01 01 03
                  NULL               05 00
              SEQUENCE               30 0d
                  OBJECT IDENTIFIER  06 09 2b 06 01 02 01 04 16 01 02
                  NULL               05 00
              SEQUENCE               30 0d
                  OBJECT IDENTIFIER  06 09 2b 06 01 02 01 04 16 01 04
                  NULL               05 00
      Note that the initial SEQUENCE is not encoded using the
      minimum number of length octets.  (The first octet of the
      length, 82, indicates that the length of the content is
      encoded in the next two octets.)
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      9.  Acknowledgements
      The UDP-based mapping is based, in part, on RFC 1157.
      The OSI-based mapping is based, in part, on RFC 1283.
      The DDP-based mapping is based, in part, on earlier work by
      Greg Minshall of Novell, Inc., and Mike Ritter of Apple
      Computer, Inc.
      The IPX-based mapping is based, in part, on RFC 1298.
      The section on proxy to community-based SNMP is based on
      earlier work that was based in part on a suggestion by
      Jonathan Biggar of Netlabs, Inc.
      Finally, the comments of the SNMP version 2 working group are
      gratefully acknowledged:
           Beth Adams, Network Management Forum
           Steve Alexander, INTERACTIVE Systems Corporation
           David Arneson, Cabletron Systems
           Toshiya Asaba
           Fred Baker, ACC
           Jim Barnes, Xylogics, Inc.
           Brian Bataille
           Andy Bierman, SynOptics Communications, Inc.
           Uri Blumenthal, IBM Corporation
           Fred Bohle, Interlink
           Jack Brown
           Theodore Brunner, Bellcore
           Stephen F. Bush, GE Information Services
           Jeffrey D. Case, University of Tennessee, Knoxville
           John Chang, IBM Corporation
           Szusin Chen, Sun Microsystems
           Robert Ching
           Chris Chiotasso, Ungermann-Bass
           Bobby A. Clay, NASA/Boeing
           John Cooke, Chipcom
           Tracy Cox, Bellcore
           Juan Cruz, Datability, Inc.
           David Cullerot, Cabletron Systems
           Cathy Cunningham, Microcom
           James R. (Chuck) Davin, Bellcore
           Michael Davis, Clearpoint
      RFC 1449        Transport Mappings for SNMPv2       April 1993
           Mike Davison, FiberCom
           Cynthia DellaTorre, MITRE
           Taso N. Devetzis, Bellcore
           Manual Diaz, DAVID Systems, Inc.
           Jon Dreyer, Sun Microsystems
           David Engel, Optical Data Systems
           Mike Erlinger, Lexcel
           Roger Fajman, NIH
           Daniel Fauvarque, Sun Microsystems
           Karen Frisa, CMU
           Shari Galitzer, MITRE
           Shawn Gallagher, Digital Equipment Corporation
           Richard Graveman, Bellcore
           Maria Greene, Xyplex, Inc.
           Michel Guittet, Apple
           Robert Gutierrez, NASA
           Bill Hagerty, Cabletron Systems
           Gary W. Haney, Martin Marietta Energy Systems
           Patrick Hanil, Nokia Telecommunications
           Matt Hecht, SNMP Research, Inc.
           Edward A. Heiner, Jr., Synernetics Inc.
           Susan E. Hicks, Martin Marietta Energy Systems
           Geral Holzhauer, Apple
           John Hopprich, DAVID Systems, Inc.
           Jeff Hughes, Hewlett-Packard
           Robin Iddon, Axon Networks, Inc.
           David Itusak
           Kevin M. Jackson, Concord Communications, Inc.
           Ole J. Jacobsen, Interop Company
           Ronald Jacoby, Silicon Graphics, Inc.
           Satish Joshi, SynOptics Communications, Inc.
           Frank Kastenholz, FTP Software
           Mark Kepke, Hewlett-Packard
           Ken Key, SNMP Research, Inc.
           Zbiginew Kielczewski, Eicon
           Jongyeoi Kim
           Andrew Knutsen, The Santa Cruz Operation
           Michael L. Kornegay, VisiSoft
           Deirdre C. Kostik, Bellcore
           Cheryl Krupczak, Georgia Tech
           Mark S. Lewis, Telebit
           David Lin
           David Lindemulder, AT&T/NCR
           Ben Lisowski, Sprint
           David Liu, Bell-Northern Research
      RFC 1449        Transport Mappings for SNMPv2       April 1993
           John Lunny, The Wollongong Group
           Robert C. Lushbaugh Martin, Marietta Energy Systems
           Michael Luufer, BBN
           Carl Madison, Star-Tek, Inc.
           Keith McCloghrie, Hughes LAN Systems
           Evan McGinnis, 3Com Corporation
           Bill McKenzie, IBM Corporation
           Donna McMaster, SynOptics Communications, Inc.
           John Medicke, IBM Corporation
           Doug Miller, Telebit
           Dave Minnich, FiberCom
           Mohammad Mirhakkak, MITRE
           Rohit Mital, Protools
           George Mouradian, AT&T Bell Labs
           Patrick Mullaney, Cabletron Systems
           Dan Myers, 3Com Corporation
           Rina Nathaniel, Rad Network Devices Ltd.
           Hien V. Nguyen, Sprint
           Mo Nikain
           Tom Nisbet
           William B. Norton, MERIT
           Steve Onishi, Wellfleet Communications, Inc.
           David T. Perkins, SynOptics Communications, Inc.
           Carl Powell, BBN
           Ilan Raab, SynOptics Communications, Inc.
           Richard Ramons, AT&T
           Venkat D. Rangan, Metric Network Systems, Inc.
           Louise Reingold, Sprint
           Sam Roberts, Farallon Computing, Inc.
           Kary Robertson, Concord Communications, Inc.
           Dan Romascanu, Lannet Data Communications Ltd.
           Marshall T. Rose, Dover Beach Consulting, Inc.
           Shawn A. Routhier, Epilogue Technology Corporation
           Chris Rozman
           Asaf Rubissa, Fibronics
           Jon Saperia, Digital Equipment Corporation
           Michael Sapich
           Mike Scanlon, Interlan
           Sam Schaen, MITRE
           John Seligson, Ultra Network Technologies
           Paul A. Serice, Corporation for Open Systems
           Chris Shaw, Banyan Systems
           Timon Sloane
           Robert Snyder, Cisco Systems
           Joo Young Song
      RFC 1449        Transport Mappings for SNMPv2       April 1993
           Roy Spitier, Sprint
           Einar Stefferud, Network Management Associates
           John Stephens, Cayman Systems, Inc.
           Robert L. Stewart, Xyplex, Inc. (chair)
           Kaj Tesink, Bellcore
           Dean Throop, Data General
           Ahmet Tuncay, France Telecom-CNET
           Maurice Turcotte, Racal Datacom
           Warren Vik, INTERACTIVE Systems Corporation
           Yannis Viniotis
           Steven L. Waldbusser, Carnegie Mellon Universitty
           Timothy M. Walden, ACC
           Alice Wang, Sun Microsystems
           James Watt, Newbridge
           Luanne Waul, Timeplex
           Donald E. Westlake III, Digital Equipment Corporation
           Gerry White
           Bert Wijnen, IBM Corporation
           Peter Wilson, 3Com Corporation
           Steven Wong, Digital Equipment Corporation
           Randy Worzella, IBM Corporation
           Daniel Woycke, MITRE
           Honda Wu
           Jeff Yarnell, Protools
           Chris Young, Cabletron
           Kiho Yum, 3Com Corporation
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      10.  References
      [1]  Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
           "Protocol Operations for version 2 of the Simple Network
           Management Protocol (SNMPv2)", RFC 1448, SNMP Research,
           Inc., Hughes LAN Systems, Dover Beach Consulting, Inc.,
           Carnegie Mellon University, April 1993.
      [2]  Postel, J., "User Datagram Protocol", STD 6, RFC 768,
           USC/Information Sciences Institute, August 1980.
      [3]  Information processing systems - Open Systems
           Interconnection - Transport Service Definition,
           International Organization for Standardization.
           International Standard 8072, (June, 1986).
      [4]  Information processing systems - Open Systems
           Interconnection - Transport Service Definition - Addendum
           1: Connectionless-mode Transmission, International
           Organization for Standardization.  International Standard
           8072/AD 1, (December, 1986).
      [5]  G. Sidhu, R. Andrews, A. Oppenheimer, Inside AppleTalk
           (second edition).  Addison-Wesley, 1990.
      [6]  Waldbusser, S., "AppleTalk Management Information Base",
           RFC 1243, Carnegie Mellon University, July 1991.
      [7]  Network System Technical Interface Overview.  Novell,
           Inc, (June, 1989).
      [8]  Case, J., Fedor, M., Schoffstall, M., Davin, J., "Simple
           Network Management Protocol", STD 15, RFC 1157, SNMP
           Research, Performance Systems International, MIT
           Laboratory for Computer Science, May 1990.
      [9]  Case, J., McCloghrie, K., Rose, M., and Waldbusser, S.,
           "Coexistence between version 1 and version 2 of the
           Internet-standard Network Management Framework", RFC
           1452, SNMP Research, Inc., Hughes LAN Systems, Dover
           Beach Consulting, Inc., Carnegie Mellon University, April
           1993.
      [10] McCloghrie, K., and Galvin, J., "Party MIB for version 2
           of the Simple Network Management Protocol (SNMPv2)", RFC
      RFC 1449        Transport Mappings for SNMPv2       April 1993
           1447, Hughes LAN Systems, Trusted Information Systems,
           April 1993.
      [11] Information processing systems - Open Systems
           Interconnection - Specification of Basic Encoding Rules
           for Abstract Syntax Notation One (ASN.1), International
           Organization for Standardization.  International Standard
           8825, (December, 1987).
      RFC 1449        Transport Mappings for SNMPv2       April 1993
      11.  Security Considerations
      Security issues are not discussed in this memo.
      12.  Authors' Addresses
           Jeffrey D. Case
           SNMP Research, Inc.
           3001 Kimberlin Heights Rd.
           Knoxville, TN  37920-9716
           US
           Phone: +1 615 573 1434
           Email: [email protected]
           Keith McCloghrie
           Hughes LAN Systems
           1225 Charleston Road
           Mountain View, CA  94043
           US
           Phone: +1 415 966 7934
           Email: [email protected]
           Marshall T. Rose
           Dover Beach Consulting, Inc.
           420 Whisman Court
           Mountain View, CA  94043-2186
           US
           Phone: +1 415 968 1052
           Email: [email protected]
           Steven Waldbusser
           Carnegie Mellon University
           4910 Forbes Ave
           Pittsburgh, PA  15213
           US
           Phone: +1 412 268 6628
           Email: [email protected]