rfc1658.txt

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Network Working Group                                         B. Stewart
Request for Comments: 1658                                  Xyplex, Inc.
Obsoletes: 1316                                                July 1994
Category: Standards Track


      Definitions of Managed Objects for Character Stream Devices
                              using SMIv2

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Table of Contents

   1. Introduction ................................................    2
   2. The SNMPv2 Network Management Framework .....................    2
   2.1 Object Definitions .........................................    3
   3. Overview ....................................................    3
   3.1 Relationship to Interface MIB ..............................    4
   4. Definitions .................................................    4
   5. Acknowledgements ............................................   17
   6. References ..................................................   17
   7. Security Considerations .....................................   18
   8. Author's Address ............................................   18

1.  Introduction

   This memo defines an extension to the Management Information Base
   (MIB) for use with network management protocols in the Internet
   community.  In particular, it defines objects for the management of
   character stream devices.

2.  The SNMPv2 Network Management Framework

   The SNMPv2 Network Management Framework consists of four major
   components.  They are:

      o    RFC 1442 [1] which defines the SMI, the mechanisms used for
           describing and naming objects for the purpose of management.

      o    STD 17, RFC 1213 [2] defines MIB-II, the core set of managed
           objects for the Internet suite of protocols.




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RFC 1658                     Character MIB                     July 1994


      o    RFC 1445 [3] which defines the administrative and other
           architectural aspects of the framework.

      o    RFC 1448 [4] which defines the protocol used for network
           access to managed objects.

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

2.1.  Object Definitions

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  Objects in the MIB are
   defined using the subset of Abstract Syntax Notation One (ASN.1)
   defined in the SMI.  In particular, each object object type is named
   by an OBJECT IDENTIFIER, an administratively assigned name.  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 descriptor, to
   refer to the object type.

3.  Overview

   The Character MIB applies to ports that carry a character stream,
   whether physical or virtual, serial or parallel, synchronous or
   asynchronous.  The most common example of a character stream device
   is a hardware terminal port with an RS-232 interface.  Another common
   hardware example is a parallel printer port, say with a Centronics
   interface.  The concept also includes virtual terminal ports, such as
   a software connection point for a remote console.

   The Character MIB is mandatory for all systems that offer character
   stream ports.  This includes, for example, terminal servers,
   general-purpose time-sharing hosts, and even such systems as a bridge
   with a (virtual) console port.  It may or may not include character
   ports that do not support network sessions, depending on the system's
   needs.

   The Character MIB's central abstraction is a port.  Physical ports
   have a one-to-one correspondence with hardware ports. Virtual ports
   are software entities analogous to physical ports, but with no
   hardware connector.

   Each port supports one or more sessions.  A session represents a
   virtual connection that carries characters between the port and some
   partner.  Sessions typically operate over a stack of network
   protocols.  A typical session, for example, uses Telnet over TCP.




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RFC 1658                     Character MIB                     July 1994


   The MIB comprises one base object and two tables, detailed in the
   following sections.  The tables contain objects for ports and
   sessions.

   The MIB intentionally contains no distinction between what is often
   called permanent and operational or volatile data bases.  For the
   purposes of this MIB, handling of such distinctions is implementation
   specific.

3.1.  Relationship to Interface MIB

   The Character MIB does not relate directly to the Interface MIB [1],
   since it is not intrinsically a network interface.  On the other
   hand, in most implementations where it is present, it will be above a
   physical sublayer interface, such as the RS-232-like [2] or
   Parallel-printer-like [3] MIBs.  Such physical interfaces typically
   are represented by a row in the interface table (ifTable), identified
   by a value of ifIndex.

4.  Definitions

   CHARACTER-MIB DEFINITIONS ::= BEGIN

   IMPORTS
       MODULE-IDENTITY, OBJECT-TYPE, NOTIFICATION-TYPE,
       Counter32, Integer32, Gauge32, TimeTicks
           FROM SNMPv2-SMI
       AutonomousType, InstancePointer
           FROM SNMPv2-TC
       InterfaceIndex
           FROM IF-MIB
       transmission, mib-2
           FROM RFC1213-MIB
       MODULE-COMPLIANCE, OBJECT-GROUP
           FROM SNMPv2-CONF;


   char MODULE-IDENTITY
       LAST-UPDATED "9405261700Z"
       ORGANIZATION "IETF Character MIB Working Group"
       CONTACT-INFO
               "        Bob Stewart
                Postal: Xyplex, Inc.
                        295 Foster Street
                        Littleton, MA 01460

                   Tel: [phone]
                   Fax: [phone]



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                E-mail: [e-mail]"
       DESCRIPTION
               "The MIB module for character stream devices."
       ::= { mib-2 19 }

   PortIndex ::= TEXTUAL-CONVENTION
       DISPLAY-HINT "d"
       STATUS current
       DESCRIPTION
               "A unique value, greater than zero, for each
               character port in the managed system.  It is
               recommended that values are assigned contiguously
               starting from 1.  The value for each interface sub-
               layer must remain constant at least from one re-
               initialization of the entity's network management
               system to the next re-initialization.

               In a system where the character ports are attached
               to hardware represented by an ifIndex, it is
               conventional, but not required, to make the
               character port index equal to the corresponding
               ifIndex."
       SYNTAX Integer32


   -- Generic Character information

   charNumber OBJECT-TYPE
       SYNTAX Integer32
       MAX-ACCESS read-only
       STATUS current
       DESCRIPTION
           "The number of entries in charPortTable, regardless
           of their current state."
       ::= { char 1 }


   -- the Character Port table

   charPortTable OBJECT-TYPE
       SYNTAX SEQUENCE OF CharPortEntry
       MAX-ACCESS not-accessible
       STATUS current
       DESCRIPTION
           "A list of port entries.  The number of entries is
           given by the value of charNumber."
       ::= { char 2 }




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   charPortEntry OBJECT-TYPE
       SYNTAX CharPortEntry
       MAX-ACCESS not-accessible
       STATUS current
       DESCRIPTION
           "Status and parameter values for a character port."
       INDEX { charPortIndex }
       ::= { charPortTable 1 }

   CharPortEntry ::=
       SEQUENCE {
           charPortIndex
               PortIndex,
           charPortName
               DisplayString,
           charPortType
               INTEGER,
           charPortHardware
               AutonomousType,
           charPortReset
               INTEGER,
           charPortAdminStatus
               INTEGER,
           charPortOperStatus
               INTEGER,
           charPortLastChange
               TimeTicks,
           charPortInFlowType
               INTEGER,
           charPortOutFlowType
               INTEGER,
           charPortInFlowState
               INTEGER,
           charPortOutFlowState
               INTEGER,
           charPortInCharacters
               Counter32,
           charPortOutCharacters
               Counter32,
           charPortAdminOrigin
               INTEGER,
           charPortSessionMaximum
               INTEGER,
           charPortSessionNumber
               Gauge32,
           charPortSessionIndex
               INTEGER,
           charPortInFlowTypes



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RFC 1658                     Character MIB                     July 1994


               OCTET STRING,
           charPortOutFlowTypes
               OCTET STRING,
           charPortLowerIfIndex
               InterfaceIndex
       }

   charPortIndex OBJECT-TYPE
       SYNTAX PortIndex
       MAX-ACCESS read-only
       STATUS current
       DESCRIPTION
           "A unique value for each character port, perhaps
           corresponding to the same value of ifIndex when the
           character port is associated with a hardware port
           represented by an ifIndex."
       ::= { charPortEntry 1 }

   charPortName OBJECT-TYPE
       SYNTAX DisplayString (SIZE (0..32))
       MAX-ACCESS read-write
       STATUS current
       DESCRIPTION
           "An administratively assigned name for the port,
           typically with some local significance."
       ::= { charPortEntry 2 }

   charPortType OBJECT-TYPE
       SYNTAX INTEGER { physical(1), virtual(2) }
       MAX-ACCESS read-only
       STATUS current
       DESCRIPTION
           "The port's type, 'physical' if the port represents
           an external hardware connector, 'virtual' if it does
           not."
       ::= { charPortEntry 3 }

   charPortHardware OBJECT-TYPE
       SYNTAX AutonomousType
       MAX-ACCESS read-only
       STATUS current
       DESCRIPTION
           "A reference to hardware MIB definitions specific to
           a physical port's external connector.  For example,
           if the connector is RS-232, then the value of this
           object refers to a MIB sub-tree defining objects
           specific to RS-232.  If an agent is not configured
           to have such values, the agent returns the object



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