rfc1318.txt

RFC 的详细文档！

Network Working Group                                 B. Stewart, Editor
Request for Comments: 1318                                  Xyplex, Inc.
                                                              April 1992


                     Definitions of Managed Objects
               for Parallel-printer-like Hardware Devices

Status of this Memo

   This document specifies 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.

1.  Abstract

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in TCP/IP based internets.
   In particular, it defines objects for the management of
   parallel-printer-like devices.

2.  The Network Management Framework

   The Internet-standard Network Management Framework consists
   of three components.  They are:

   RFC 1155 which defines the SMI, the mechanisms used for
   describing and naming objects for the purpose of management.
   RFC 1212 defines a more concise description mechanism, which
   is wholly consistent with the SMI.

   RFC 1156 which defines MIB-I, the core set of managed
   objects for the Internet suite of protocols.  RFC 1213,
   defines MIB-II, an evolution of MIB-I based on
   implementation experience and new operational requirements.

   RFC 1157 which defines the SNMP, the protocol used for
   network access to managed objects.

   The Framework permits new objects to be defined for the
   purpose of experimentation and evaluation.

3.  Objects

   Managed objects are accessed via a virtual information
   store, termed the Management Information Base or MIB.



Character MIB Working Group                                     [Page 1]

RFC 1318               PARALLEL-PRINTER-LIKE-MIB              April 1992


   Objects in the MIB are defined using the subset of Abstract
   Syntax Notation One (ASN.1) [7] defined in the SMI.  In
   particular, each object has a name, a syntax, and an
   encoding.  The name is an object identifier, an
   administratively assigned name, which specifies an object
   type.

   The object type together with an object instance serves to
   uniquely identify a specific instantiation of the object.
   For human convenience, we often use a textual string, termed
   the OBJECT DESCRIPTOR, to also refer to the object type.

   The syntax of an object type defines the abstract data
   structure corresponding to that object type.  The ASN.1
   language is used for this purpose.  However, the SMI [3]
   purposely restricts the ASN.1 constructs which may be used.
   These restrictions are explicitly made for simplicity.

   The encoding of an object type is simply how that object
   type is represented using the object type's syntax.
   Implicitly tied to the notion of an object type's syntax and
   encoding is how the object type is represented when being
   transmitted on the network.

   The SMI specifies the use of the basic encoding rules of
   ASN.1 [8], subject to the additional requirements imposed by
   the SNMP.

3.1.  Format of Definitions

   Section 5 contains the specification of all object types
   contained in this MIB module.  The object types are defined
   using the conventions defined in the SMI, as amended by the
   extensions specified in [9,10].

4.  Overview

   The Parallel-printer-like Hardware Device MIB applies to
   interface ports that might logically support the Interface
   MIB, a Transmission MIB, or the Character MIB (most likely
   the latter).  The most common example is a Centronics or
   Data Products type parallel printer port.

   The Parallel-printer-like MIB is one of a set of MIBs
   designed for complementary use.  At this writing, the set
   comprises:





Character MIB Working Group                                     [Page 2]

RFC 1318               PARALLEL-PRINTER-LIKE-MIB              April 1992


        Character MIB
        PPP MIB
        RS-232-like MIB
        Parallel-printer-like MIB

   The RS-232-like MIB and the Parallel-printer-like MIB
   represent the physical layer, providing service to higher
   layers such as the Character MIB or PPP MIB.  Further MIBs
   may appear above these.

   The following diagram shows two possible "MIB stacks", each
   using the RS-232-like MIB.

                                    .-----------------.
         .-----------------.        |  Standard MIB   |
         |   Telnet MIB    |        | Interface Group |
         |-----------------|        |-----------------|
         |  Character MIB  |        |     PPP MIB     |
         |-----------------|        |-----------------|
         | RS-232-like MIB |        | RS-232-like MIB |
         `-----------------'        `-----------------'

   The intent of the model is for the physical-level MIBs to
   represent the lowest level, regardless of the higher level
   that may be using it.  In turn, separate higher level MIBs
   represent specific applications, such as a terminal (the
   Character MIB) or a network connection (the PPP MIB).

   The Parallel-printer-like MIB is mandatory for all systems
   that have such a hardware port supporting services managed
   through some other MIB, for example, the Character MIB.

   The Parallel-printer-like MIB includes multiple similar
   types of hardware, and as a result contains objects not
   applicable to all of those types.  Such objects are in a
   separate branch of the MIB, which is required when
   applicable and otherwise absent.

   The Parallel-printer-like MIB includes Centronics, Data
   Products, and other parallel physical links with a similar
   set of control signals.

   The MIB contains objects that relate to physical layer
   connections.  Such connections may provide interesting
   hardware signals (other than for basic data transfer), such
   as Power and PaperOut.

   The MIB comprises one base object and three tables, detailed



Character MIB Working Group                                     [Page 3]

RFC 1318               PARALLEL-PRINTER-LIKE-MIB              April 1992


   in the following sections.  The tables contain objects for
   ports and input and output control signals.

5.  Definitions

                    RFC1318-MIB DEFINITIONS ::= BEGIN

                    IMPORTS
                            Counter
                                    FROM RFC1155-SMI
                            transmission
                                    FROM RFC1213-MIB
                            OBJECT-TYPE
                                    FROM RFC-1212;

            -- this is the MIB module for Parallel-printer-like
            -- hardware devices

            para    OBJECT IDENTIFIER ::= { transmission 34 }

            -- the generic Parallel-printer-like group

            -- Implementation of this group is mandatory for all
            -- systems that have Parallel-printer-like hardware
            -- ports supporting higher level services such as
            -- character streams

            paraNumber OBJECT-TYPE
                SYNTAX INTEGER
                ACCESS read-only
                STATUS mandatory
                DESCRIPTION
                    "The number of ports (regardless of their current
                    state) in the Parallel-printer-like port table."
                ::= { para 1 }


            -- the Parallel-printer-like Port table

            paraPortTable OBJECT-TYPE
                SYNTAX SEQUENCE OF ParaPortEntry
                ACCESS not-accessible
                STATUS mandatory
                DESCRIPTION
                    "A list of port entries.  The number of entries is
                    given by the value of paraNumber."
                ::= { para 2 }




Character MIB Working Group                                     [Page 4]

RFC 1318               PARALLEL-PRINTER-LIKE-MIB              April 1992


            paraPortEntry OBJECT-TYPE
                SYNTAX ParaPortEntry
                ACCESS not-accessible
                STATUS mandatory
                DESCRIPTION
                    "Status and parameter values for a port."
                INDEX { paraPortIndex }
                ::= { paraPortTable 1 }

            ParaPortEntry ::=
                SEQUENCE {
                    paraPortIndex
                        INTEGER,
                    paraPortType
                        INTEGER,
                    paraPortInSigNumber
                        INTEGER,
                    paraPortOutSigNumber
                        INTEGER
                }

            paraPortIndex OBJECT-TYPE
                SYNTAX INTEGER
                ACCESS read-only
                STATUS mandatory
                DESCRIPTION
                    "A unique value for each port.  Its value ranges
                    between 1 and the value of paraNumber.  By
                    convention and if possible, hardware port numbers
                    map directly to external connectors.  The value for
                    each port must remain constant at least from one
                    re-initialization of the network management agent to
                    the next."
                ::= { paraPortEntry 1 }

            paraPortType OBJECT-TYPE
                SYNTAX INTEGER {
                    other(1),
                    centronics(2),
                    dataproducts(3)
                }
                ACCESS read-only
                STATUS mandatory
                DESCRIPTION
                    "The port's hardware type."
                ::= { paraPortEntry 2 }

            paraPortInSigNumber OBJECT-TYPE



Character MIB Working Group                                     [Page 5]

RFC 1318               PARALLEL-PRINTER-LIKE-MIB              April 1992


                SYNTAX INTEGER
                ACCESS read-only
                STATUS mandatory
                DESCRIPTION
                    "The number of input signals for the port in the
                    input signal table (paraPortInSigTable).  The table
                    contains entries only for those signals the software
                    can detect."
                ::= { paraPortEntry 3 }

            paraPortOutSigNumber OBJECT-TYPE
                SYNTAX INTEGER
                ACCESS read-only
                STATUS mandatory
                DESCRIPTION
                    "The number of output signals for the port in the
                    output signal table (paraPortOutSigTable).  The
                    table contains entries only for those signals the
                    software can assert."
                ::= { paraPortEntry 4 }


            -- the Input Signal table