rfc1317.txt

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Network Working Group                                 B. Stewart, Editor
Request for Comments: 1317                                  Xyplex, Inc.
                                                              April 1992


                  Definitions of Managed Objects for
                      RS-232-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 RS-232-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. Objects in the MIB are



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   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 RS-232-like Hardware Device MIB applies to interface ports that
   might logically support the Interface MIB, a Transmission MIB, or the
   Character MIB.  The most common example is an RS-232 port with modem
   signals.

   The RS-232-like MIB is one of a set of MIBs designed for
   complementary use.  At this writing, the set comprises:

        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.



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   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 RS-232-like Hardware Device MIB is mandatory for all systems that
   have such a hardware port supporting services managed through some
   other MIB, for example, the Character MIB or PPP MIB.

   The 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 RS-232-like Hardware Port MIB includes RS-232, RS-422, RS-423,
   V.35, and other asynchronous or synchronous, serial 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 RNG and DCD.  Hardware ports also
   have such attributes as speed and bits per character.

   Usefulness of error counters in this MIB depends on the presence of
   non-error character counts in higher level MIBs.

   The MIB comprises one base object and four tables, detailed in the
   following sections.  The tables contain objects for all ports,
   asynchronous ports, and input and output control signals.









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5.  Definitions

               RFC1317-MIB DEFINITIONS ::= BEGIN

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

       -- this is the MIB module for RS-232-like hardware devices

       rs232    OBJECT IDENTIFIER ::= { transmission 33 }


       -- the generic RS-232-like group

       -- Implementation of this group is mandatory for all
       -- systems that have RS-232-like hardware ports
       -- supporting higher level services such as character
       -- streams or network interfaces

       rs232Number OBJECT-TYPE
           SYNTAX INTEGER
           ACCESS read-only
           STATUS mandatory
           DESCRIPTION
               "The number of ports (regardless of their current
               state) in the RS-232-like general port table."
           ::= { rs232 1 }


       -- the RS-232-like general Port table

       rs232PortTable OBJECT-TYPE
           SYNTAX SEQUENCE OF Rs232PortEntry
           ACCESS not-accessible
           STATUS mandatory
           DESCRIPTION
               "A list of port entries.  The number of entries is
               given by the value of rs232Number."
           ::= { rs232 2 }

       rs232PortEntry OBJECT-TYPE
           SYNTAX Rs232PortEntry
           ACCESS not-accessible



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           STATUS mandatory
           DESCRIPTION
               "Status and parameter values for a port."
           INDEX { rs232PortIndex }
           ::= { rs232PortTable 1 }

       Rs232PortEntry ::=
           SEQUENCE {
               rs232PortIndex
                   INTEGER,
               rs232PortType
                   INTEGER,
               rs232PortInSigNumber
                   INTEGER,
               rs232PortOutSigNumber
                   INTEGER,
               rs232PortInSpeed
                   INTEGER,
               rs232PortOutSpeed
                   INTEGER    }

       rs232PortIndex 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 rs232Number.  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."
           ::= { rs232PortEntry 1 }

       rs232PortType OBJECT-TYPE
           SYNTAX INTEGER { other(1), rs232(2), rs422(3),
                            rs423(4), v35(5) }
           ACCESS read-only
           STATUS mandatory
           DESCRIPTION
               "The port's hardware type."
           ::= { rs232PortEntry 2 }

       rs232PortInSigNumber OBJECT-TYPE
           SYNTAX INTEGER
           ACCESS read-only
           STATUS mandatory



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           DESCRIPTION
               "The number of input signals for the port in the
               input signal table (rs232PortInSigTable).  The table
               contains entries only for those signals the software
               can detect."
           ::= { rs232PortEntry 3 }

       rs232PortOutSigNumber OBJECT-TYPE
           SYNTAX INTEGER
           ACCESS read-only
           STATUS mandatory
           DESCRIPTION
               "The number of output signals for the port in the
               output signal table (rs232PortOutSigTable).  The
               table contains entries only for those signals the
               software can assert."
           ::= { rs232PortEntry 4 }

       rs232PortInSpeed OBJECT-TYPE
           SYNTAX INTEGER
           ACCESS read-write
           STATUS mandatory
           DESCRIPTION
               "The port's input speed in bits per second."
           ::= { rs232PortEntry 5 }

       rs232PortOutSpeed OBJECT-TYPE
           SYNTAX INTEGER
           ACCESS read-write
           STATUS mandatory
           DESCRIPTION
               "The port's output speed in bits per second."
           ::= { rs232PortEntry 6 }