RFC1471

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Network Working Group F. Kastenholz Request for Comments: 1471 FTP Software, Inc.

                                                           June 1993
             The Definitions of Managed Objects for
                  the Link Control Protocol of
                  the Point-to-Point Protocol

Status of this Memo

This RFC 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.

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 describes managed objects used for managing the Link Control Protocol and Link Quality Monitoring on subnetwork interfaces that use the family of Point-to-Point Protocols [8, 9, 10, 11, & 12].

3.4 Relationship to Interface and Interface Extensions

The Network Management Framework

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

  STD 16/RFC 1155 which defines the SMI, the mechanisms used for
  describing and naming objects for the purpose of management.  STD
  16/RFC 1212 defines a more concise description mechanism, which is
  wholly consistent with the SMI.
  STD 17/RFC 1213 which defines MIB-II, the core set of managed
  objects for the Internet suite of protocols.
  STD 15/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.

Objects

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) [3] defined in the SMI. In particular, each 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.

Format of Definitions

Section 4 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 [5,6].

Overview

Object Selection Criteria

To be consistent with IAB directives and good engineering practice, an explicit attempt was made to keep this MIB as simple as possible. This was accomplished by applying the following criteria to objects proposed for inclusion:

  (1)  Require objects be essential for either fault or
       configuration management.  In particular, objects for
       which the sole purpose was to debug implementations were
       explicitly excluded from the MIB.
  (2)  Consider evidence of current use and/or utility.
  (3)  Limit the total number of objects.
  (4)  Exclude objects which are simply derivable from others in
       this or other MIBs.

Structure of the PPP

This section describes the basic model of PPP used in developing the PPP MIB. This information should be useful to the implementor in understanding some of the basic design decisions of the MIB.

The PPP is not one single protocol but a large family of protocols. Each of these is, in itself, a fairly complex protocol. The PPP protocols may be divided into three rough categories:

Control Protocols

  The Control Protocols are used to control the operation of the
  PPP. The Control Protocols include the Link Control Protocol
  (LCP), the Password Authentication Protocol (PAP), the Link
  Quality Report (LQR), and the Challenge Handshake Authentication
  Protocol (CHAP).

Network Protocols

  The Network Protocols are used to move the network traffic over
  the PPP interface.  A Network Protocol encapsulates the datagrams
  of a specific higher-layer protocol that is using the PPP as a
  data link.  Note that within the context of PPP, the term "Network
  Protocol" does not imply an OSI Layer-3 protocol; for instance,
  there is a Bridging network protocol.

Network Control Protocols (NCPs)

  The NCPs are used to control the operation of the Network
  Protocols. Generally, each Network Protocol has its own Network
  Control Protocol; thus, the IP Network Protocol has its IP Control
  Protocol, the Bridging Network Protocol has its Bridging Network
  Control Protocol and so on.

This document specifies the objects used in managing one of these protocols, namely the Link Control Protocol and Link Quality Monitoring Protocol.

MIB Groups

Objects in this MIB are arranged into several MIB groups. Each group is organized as a set of related objects.

These groups are the basic unit of conformance: if the semantics of a group are applicable to an implementation then all objects in the group must be implemented.

The PPP MIB is organized into several MIB Groups, including, but not limited to, the following groups:

      o The PPP Link Group
      o The PPP LQR Group
      o The PPP LQR Extensions Group
      o The PPP IP Group
      o The PPP Bridge Group
      o The PPP Security Group

This document specifies the following groups:

The PPP Link Group

  This group represents the lowest "level" of the PPP protocol.
  This group contains two tables, one containing status information
  and the other configuration information.  The configuration table
  is split off of the status so that it may be placed in a separate
  MIB View for security purposes.
  Implementation of this group is mandatory for all PPP
  implementations.

The PPP LQR Group

  This group provides the basic MIB variables that apply to the PPP
  LQR Protocol.  This group provides MIB access to the information
  required for LQR processing. This group contains two tables, one
  containing status information and the other configuration
  information.  The configuration table is split off of the status
  so that it may be placed in a separate MIB View for security
  purposes.
  Implementation of the PPP LQR Group is mandatory for all PPP
  implementations that implement LQR.

The PPP LQR Extensions Group

  The PPP LQR Extensions group contains the most recently received
  LQR packet, as well as the "save" fields that are "logically
  appended" [12] to received LQR packets.  This is done in order to
  facilitate external implementations of the Link Quality Monitoring
  policies.
  It is not practical to examine the relevant MIB objects which are
  used to generate LQR packets since LQR policies may require
  synchronization of the values of all data used to determine Link
  Quality; i.e., the values of the relevant counters must all be
  taken at the same instant in time.  Thus, by recording the last
  received LQR packet, a synchronized record of the relevant data is
  available.
  As this information may not be efficiently maintained on all PPP
  implementations, implementation of this group is optional.

Relationship to Interface and Interface Extensions

  Groups

The PPP Mib is a medium-specific extension to the standard MIB-2 interface group [2] and to the Interface Extensions MIB [7]. This section discusses certain components of these groups when the interface is a PPP interface.

The PPP interface represents a single interface in the sense used in [2] and thus has a single entry in the ifTable.

Furthermore, the PPP interface may be operating over a lower layer hardware interface (such as an RS-232 port). It is important to capture the relationship between the PPP interface and the lower- layer interface over which it operates. This MIB presumes that the lower-layer interface has an ifEntry associated with it. The lower- layer ifEntry is identified via the pppLinkStatusPhysicalIndex object, which contains the value of ifIndex for the lower-layer ifEntry.

For example, suppose that you run PPP over a RS-232 port. This would use two entries in the ifTable. Let's suppose that entry number 123 is for the PPP "interface" and entry number 987 is for the RS-232 port. So, ifSpecific.123 would contain the ppp OBJECT IDENTIFIER, pppLinkStatusPhysicalIndex.123 would contain 987, and ifSpecific.987 would contain the rs_232 OBJECT IDENTIFIER (or whatever it is).

All PPP packets are defined in [8] as being broadcast packets. Thus, the packets are counted as non-unicast packets in the ifTable (ifInNUcastPkts and ifOutNUCastPkts) and as broadcasts in the ifExtnsTable (ifExtnsBroadcastsReceivedOks and ifExtnsBroadcastsTransmittedOks).

ifSpecific

  Contains the OBJECT IDENTIFIER ppp.

ifAdminStatus

  Setting this object to up will inject an administrative open event
  into the LCP's finite state machine.  Setting this object to down
  will inject an administrative close event into the LCP's finite
  state machine.
  The use of the testing value is beyond the scope of this document.

ifOperStatus

  Represents the state of the LCP Finite State Machine.  If the
  Finite State Machine is in the Opened state then the value of
  ifOperStatus is up, otherwise the value of ifOperStatus is down.
  The meaning of the testing value is beyond the scope of this
  document.

Per the SNMP Protocol Specification [13], the linkUp and linkDown traps apply to the PPP Protocol entity. When the LCP's Finite State Machine attains the Opened state, a linkUp trap should be sent. When the Finite State Machine leaves the Opened state, a linkDown trap should be sent.

Some tests for the link are defined in this document. Execution of these tests does not place the link's ifOperStatus in the testing state as these tests do not prevent normal data transmission from occuring over the link.

Definitions

      PPP-LCP-MIB DEFINITIONS ::= BEGIN
      IMPORTS
           Counter
                FROM RFC1155-SMI
           ifIndex, transmission
                FROM RFC1213-MIB
           OBJECT-TYPE
                FROM RFC-1212;
           --  PPP MIB
           ppp  OBJECT IDENTIFIER ::= { transmission 23 }
           pppLcp OBJECT IDENTIFIER ::= { ppp 1 }
           -- The individual groups within the PPP-LCP-MIB
           pppLink      OBJECT IDENTIFIER ::= { pppLcp 1 }
           pppLqr       OBJECT IDENTIFIER ::= { pppLcp 2 }
           pppTests     OBJECT IDENTIFIER ::= { pppLcp 3 }
      -- 4.1.  PPP Link Group
      --
      -- The PPP Link Group. Implementation of this
      -- group is mandatory for all PPP entities.
      --
      -- The following object reflect the values of the option
      -- parameters used in the PPP Link Control Protocol
      --   pppLinkStatusLocalMRU
      --   pppLinkStatusRemoteMRU
      --   pppLinkStatusLocalToPeerACCMap
      --   pppLinkStatusPeerToLocalACCMap
      --   pppLinkStatusLocalToRemoteProtocolCompression
      --   pppLinkStatusRemoteToLocalProtocolCompression
      --   pppLinkStatusLocalToRemoteACCompression
      --   pppLinkStatusRemoteToLocalACCompression
      --   pppLinkStatusTransmitFcsSize
      --   pppLinkStatusReceiveFcsSize
      --
      -- These values are not available until after the PPP Option
      -- negotiation has completed, which is indicated by the link
      -- reaching the open state (i.e., ifOperStatus is set to
      -- up).
      --
      -- Therefore, when ifOperStatus is not up
      -- the contents of these objects is undefined. The value
      -- returned when accessing the objects is an implementation
      -- dependent issue.
      pppLinkStatusTable   OBJECT-TYPE
           SYNTAX    SEQUENCE OF PppLinkStatusEntry
           ACCESS    not-accessible
           STATUS    mandatory
           DESCRIPTION
                     "A table containing PPP-link specific variables
                     for this PPP implementation."
           ::= { pppLink 1 }
      pppLinkStatusEntry   OBJECT-TYPE
           SYNTAX    PppLinkStatusEntry
           ACCESS    not-accessible
           STATUS    mandatory
           DESCRIPTION
                     "Management information about a particular PPP
                     Link."
           INDEX     { ifIndex }
           ::= { pppLinkStatusTable 1 }
      PppLinkStatusEntry ::= SEQUENCE {
           pppLinkStatusPhysicalIndex
                INTEGER,
           pppLinkStatusBadAddresses
                Counter,
           pppLinkStatusBadControls
                Counter,
           pppLinkStatusPacketTooLongs
                Counter,
           pppLinkStatusBadFCSs
                Counter,
           pppLinkStatusLocalMRU
                INTEGER,
           pppLinkStatusRemoteMRU
                INTEGER,
           pppLinkStatusLocalToPeerACCMap
                OCTET STRING,
           pppLinkStatusPeerToLocalACCMap
                OCTET STRING,
           pppLinkStatusLocalToRemoteProtocolCompression
                INTEGER,
           pppLinkStatusRemoteToLocalProtocolCompression
                INTEGER,
           pppLinkStatusLocalToRemoteACCompression
                INTEGER,
           pppLinkStatusRemoteToLocalACCompression
                INTEGER,
           pppLinkStatusTransmitFcsSize
                INTEGER,
           pppLinkStatusReceiveFcsSize
                INTEGER
           }
      pppLinkStatusPhysicalIndex   OBJECT-TYPE
           SYNTAX    INTEGER(0..2147483647)
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The value of ifIndex that identifies the
                     lower-level interface over which this PPP Link
                     is operating. This interface would usually be
                     an HDLC or RS-232 type of interface. If there
                     is no lower-layer interface element, or there
                     is no ifEntry for the element, or the element
                     can not be identified, then the value of this
                     object is 0.  For example, suppose that PPP is
                     operating over a serial port. This would use
                     two entries in the ifTable. The PPP could be
                     running over `interface' number 123 and the
                     serial port could be running over `interface'
                     number 987.  Therefore, ifSpecific.123 would
                     contain the OBJECT IDENTIFIER ppp
                     pppLinkStatusPhysicalIndex.123 would contain
                     987, and ifSpecific.987 would contain the
                     OBJECT IDENTIFIER for the serial-port's media-
                     specific MIB."
           ::= { pppLinkStatusEntry 1 }
      pppLinkStatusBadAddresses   OBJECT-TYPE
           SYNTAX    Counter
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The number of packets received with an
                     incorrect Address Field. This counter is a
                     component of the ifInErrors variable that is
                     associated with the interface that represents
                     this PPP Link."
           REFERENCE
                     "Section 3.1, Address Field, of RFC1331."
           ::= { pppLinkStatusEntry 2 }
      pppLinkStatusBadControls   OBJECT-TYPE
           SYNTAX    Counter
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The number of packets received on this link
                     with an incorrect Control Field. This counter
                     is a component of the ifInErrors variable that
                     is associated with the interface that
                     represents this PPP Link."
           REFERENCE
                     "Section 3.1, Control Field, of RFC1331."
           ::= { pppLinkStatusEntry 3 }
      pppLinkStatusPacketTooLongs   OBJECT-TYPE
           SYNTAX    Counter
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The number of received packets that have been
                     discarded because their length exceeded the
                     MRU. This counter is a component of the
                     ifInErrors variable that is associated with the
                     interface that represents this PPP Link. NOTE,
                     packets which are longer than the MRU but which
                     are successfully received and processed are NOT
                     included in this count."
           ::= { pppLinkStatusEntry 4 }
      pppLinkStatusBadFCSs   OBJECT-TYPE
           SYNTAX    Counter
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The number of received packets that have been
                     discarded due to having an incorrect FCS. This
                     counter is a component of the ifInErrors
                     variable that is associated with the interface
                     that represents this PPP Link."
           ::= { pppLinkStatusEntry 5 }
      pppLinkStatusLocalMRU   OBJECT-TYPE
           SYNTAX    INTEGER(1..2147483648)
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The current value of the MRU for the local PPP
                     Entity. This value is the MRU that the remote
                     entity is using when sending packets to the
                     local PPP entity. The value of this object is
                     meaningful only when the link has reached the
                     open state (ifOperStatus is up)."
           ::= { pppLinkStatusEntry 6 }
      pppLinkStatusRemoteMRU   OBJECT-TYPE
           SYNTAX    INTEGER(1..2147483648)
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The current value of the MRU for the remote
                     PPP Entity. This value is the MRU that the
                     local entity is using when sending packets to
                     the remote PPP entity. The value of this object
                     is meaningful only when the link has reached
                     the open state (ifOperStatus is up)."
           ::= { pppLinkStatusEntry 7 }
      pppLinkStatusLocalToPeerACCMap   OBJECT-TYPE
           SYNTAX    OCTET STRING (SIZE (4))
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The current value of the ACC Map used for
                     sending packets from the local PPP entity to
                     the remote PPP entity. The value of this object
                     is meaningful only when the link has reached
                     the open state (ifOperStatus is up)."
           ::= { pppLinkStatusEntry 8 }
      pppLinkStatusPeerToLocalACCMap   OBJECT-TYPE
           SYNTAX    OCTET STRING (SIZE (4))
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The ACC Map used by the remote PPP entity when
                     transmitting packets to the local PPP entity.
                     The value of this object is meaningful only
                     when the link has reached the open state
                     (ifOperStatus is up)."
           ::= { pppLinkStatusEntry 9 }
      pppLinkStatusLocalToRemoteProtocolCompression
           OBJECT-TYPE
           SYNTAX    INTEGER {
                     enabled(1),
                     disabled(2)
                }
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "Indicates whether the local PPP entity will
                     use Protocol Compression when transmitting
                     packets to the remote PPP entity. The value of
                     this object is meaningful only when the link
                     has reached the open state (ifOperStatus is
                     up)."
           ::= { pppLinkStatusEntry 10 }
      pppLinkStatusRemoteToLocalProtocolCompression
           OBJECT-TYPE
           SYNTAX    INTEGER {
                     enabled(1),
                     disabled(2)
                }
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "Indicates whether the remote PPP entity will
                     use Protocol Compression when transmitting
                     packets to the local PPP entity. The value of
                     this object is meaningful only when the link
                     has reached the open state (ifOperStatus is
                     up)."
           ::= { pppLinkStatusEntry 11 }
      pppLinkStatusLocalToRemoteACCompression   OBJECT-TYPE
           SYNTAX    INTEGER {
                     enabled(1),
                     disabled(2)
                }
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "Indicates whether the local PPP entity will
                     use Address and Control Compression when
                     transmitting packets to the remote PPP entity.
                     The value of this object is meaningful only
                     when the link has reached the open state
                     (ifOperStatus is up)."
           ::= { pppLinkStatusEntry 12 }
      pppLinkStatusRemoteToLocalACCompression   OBJECT-TYPE
           SYNTAX    INTEGER {
                     enabled(1),
                     disabled(2)
                }
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "Indicates whether the remote PPP entity will
                     use Address and Control Compression when
                     transmitting packets to the local PPP entity.
                     The value of this object is meaningful only
                     when the link has reached the open state
                     (ifOperStatus is up)."
           ::= { pppLinkStatusEntry 13 }
      pppLinkStatusTransmitFcsSize   OBJECT-TYPE
           SYNTAX    INTEGER (0..128)
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The size of the Frame Check Sequence (FCS) in
                     bits that the local node will generate when
                     sending packets to the remote node. The value
                     of this object is meaningful only when the link
                     has reached the open state (ifOperStatus is
                     up)."
           ::= { pppLinkStatusEntry 14 }
      pppLinkStatusReceiveFcsSize   OBJECT-TYPE
           SYNTAX    INTEGER (0..128)
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The size of the Frame Check Sequence (FCS) in
                     bits that the remote node will generate when
                     sending packets to the local node. The value of
                     this object is meaningful only when the link
                     has reached the open state (ifOperStatus is
                     up)."
           ::= { pppLinkStatusEntry 15 }
      pppLinkConfigTable   OBJECT-TYPE
           SYNTAX    SEQUENCE OF PppLinkConfigEntry
           ACCESS    not-accessible
           STATUS    mandatory
           DESCRIPTION
                     "A table containing the LCP configuration
                     parameters for this PPP Link. These variables
                     represent the initial configuration of the PPP
                     Link. The actual values of the parameters may
                     be changed when the link is brought up via the
                     LCP options negotiation mechanism."
           ::= { pppLink 2 }
      pppLinkConfigEntry   OBJECT-TYPE
           SYNTAX    PppLinkConfigEntry
           ACCESS    not-accessible
           STATUS    mandatory
           DESCRIPTION
                     "Configuration information about a particular
                     PPP Link."
           INDEX     { ifIndex }
           ::= { pppLinkConfigTable 1 }
      PppLinkConfigEntry ::= SEQUENCE {
           pppLinkConfigInitialMRU
                INTEGER,
           pppLinkConfigReceiveACCMap
                OCTET STRING,
           pppLinkConfigTransmitACCMap
                OCTET STRING,
           pppLinkConfigMagicNumber
                INTEGER,
           pppLinkConfigFcsSize
                INTEGER
           }
      pppLinkConfigInitialMRU   OBJECT-TYPE
           SYNTAX    INTEGER(0..2147483647)
           ACCESS    read-write
           STATUS    mandatory
           DESCRIPTION
                     "The initial Maximum Receive Unit (MRU) that
                     the local PPP entity will advertise to the
                     remote entity. If the value of this variable is
                     0 then the local PPP entity will not advertise
                     any MRU to the remote entity and the default
                     MRU will be assumed. Changing this object will
                     have effect when the link is next restarted."
           REFERENCE
                     "Section 7.2, Maximum Receive Unit of RFC1331."
           DEFVAL    { 1500 }
           ::= { pppLinkConfigEntry 1 }
      pppLinkConfigReceiveACCMap   OBJECT-TYPE
           SYNTAX    OCTET STRING (SIZE (4))
           ACCESS    read-write
           STATUS    mandatory
           DESCRIPTION
                     "The Asynchronous-Control-Character-Map (ACC)
                     that the local PPP entity requires for use on
                     its receive side. In effect, this is the ACC
                     Map that is required in order to ensure that
                     the local modem will successfully receive all
                     characters. The actual ACC map used on the
                     receive side of the link will be a combination
                     of the local node's pppLinkConfigReceiveACCMap
                     and the remote node's
                     pppLinkConfigTransmitACCMap. Changing this
                     object will have effect when the link is next
                     restarted."
           REFERENCE
                     "Section 7.3, page 4, Async-Control-Character-
                     Map of RFC1331."
           DEFVAL    { 'ffffffff'h }
           ::= { pppLinkConfigEntry 2 }
      pppLinkConfigTransmitACCMap   OBJECT-TYPE
           SYNTAX    OCTET STRING (SIZE (4))
           ACCESS    read-write
           STATUS    mandatory
           DESCRIPTION
                     "The Asynchronous-Control-Character-Map (ACC)
                     that the local PPP entity requires for use on
                     its transmit side. In effect, this is the ACC
                     Map that is required in order to ensure that
                     all characters can be successfully transmitted
                     through the local modem.  The actual ACC map
                     used on the transmit side of the link will be a
                     combination of the local node's
                     pppLinkConfigTransmitACCMap and the remote
                     node's pppLinkConfigReceiveACCMap. Changing
                     this object will have effect when the link is
                     next restarted."
           REFERENCE
                     "Section 7.3, page 4, Async-Control-Character-
                     Map of RFC1331."
           DEFVAL    { 'ffffffff'h }
           ::= { pppLinkConfigEntry 3 }
      pppLinkConfigMagicNumber   OBJECT-TYPE
           SYNTAX    INTEGER {false (1), true (2)}
           ACCESS    read-write
           STATUS    mandatory
           DESCRIPTION
                     "If true(2) then the local node will attempt to
                     perform Magic Number negotiation with the
                     remote node. If false(1) then this negotiation
                     is not performed. In any event, the local node
                     will comply with any magic number negotiations
                     attempted by the remote node, per the PPP
                     specification. Changing this object will have
                     effect when the link is next restarted."
           REFERENCE
                     "Section 7.6, Magic Number, of RFC1331."
           DEFVAL    { false }
           ::= { pppLinkConfigEntry 4 }
      pppLinkConfigFcsSize   OBJECT-TYPE
           SYNTAX    INTEGER (0..128)
           ACCESS    read-write
           STATUS    mandatory
           DESCRIPTION
                     "The size of the FCS, in bits, the local node
                     will attempt to negotiate for use with the
                     remote node. Regardless of the value of this
                     object, the local node will comply with any FCS
                     size negotiations initiated by the remote node,
                     per the PPP specification. Changing this object
                     will have effect when the link is next
                     restarted."
           DEFVAL    { 16 }
           ::= { pppLinkConfigEntry 5 }
      -- 4.2.  PPP LQR Group
           --
           -- The PPP LQR Group.
           -- Implementation of this group is mandatory for all
           -- PPP implementations that implement LQR.
           --
      pppLqrTable   OBJECT-TYPE
           SYNTAX    SEQUENCE OF PppLqrEntry
           ACCESS    not-accessible
           STATUS    mandatory
           DESCRIPTION
                     "Table containing the LQR parameters and
                     statistics for the local PPP entity."
           ::= { pppLqr 1 }
      pppLqrEntry   OBJECT-TYPE
           SYNTAX    PppLqrEntry
           ACCESS    not-accessible
           STATUS    mandatory
           DESCRIPTION
                     "LQR information for a particular PPP link. A
                     PPP link will have an entry in this table if
                     and only if LQR Quality Monitoring has been
                     successfully negotiated for said link."
           INDEX     { ifIndex }
           ::= { pppLqrTable 1 }
      PppLqrEntry ::= SEQUENCE {
           pppLqrQuality
                INTEGER,
           pppLqrInGoodOctets
                Counter,
           pppLqrLocalPeriod
                INTEGER,
           pppLqrRemotePeriod
                INTEGER,
           pppLqrOutLQRs
                Counter,
           pppLqrInLQRs
                Counter
      }
      pppLqrQuality   OBJECT-TYPE
           SYNTAX    INTEGER {
                     good(1),
                     bad(2),
                     not-determined(3)
                }
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The current quality of the link as declared by
                     the local PPP entity's Link-Quality Management
                     modules. No effort is made to define good or
                     bad, nor the policy used to determine it. The
                     not-determined value indicates that the entity
                     does not actually evaluate the link's quality.
                     This value is used to disambiguate the
                     `determined to be good' case from the `no
                     determination made and presumed to be good'
                     case."
           ::= { pppLqrEntry 1 }
      pppLqrInGoodOctets   OBJECT-TYPE
           SYNTAX    Counter
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The LQR InGoodOctets counter for this link."
           REFERENCE
                     "Section 2.2, Counters, of RFC1333."
           ::= { pppLqrEntry 2 }
      pppLqrLocalPeriod   OBJECT-TYPE
           SYNTAX    INTEGER(1..2147483648)
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The LQR reporting period, in hundredths of a
                     second that is in effect for the local PPP
                     entity."
           REFERENCE
                     "Section 2.5, Configuration Option Format, of
                     RFC1333."
           ::= { pppLqrEntry 3 }
      pppLqrRemotePeriod   OBJECT-TYPE
           SYNTAX    INTEGER(1..2147483648)
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The LQR reporting period, in hundredths of a
                     second, that is in effect for the remote PPP
                     entity."
           REFERENCE
                     "Section 2.5, Configuration Option Format, of
                     RFC1333."
           ::= { pppLqrEntry 4 }
      pppLqrOutLQRs   OBJECT-TYPE
           SYNTAX    Counter
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The value of the OutLQRs counter on the local
                     node for the link identified by ifIndex."
           REFERENCE
                     "Section 2.2, Counters, of RFC1333."
           ::= { pppLqrEntry 5 }
      pppLqrInLQRs   OBJECT-TYPE
           SYNTAX    Counter
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "The value of the InLQRs counter on the local
                     node for the link identified by ifIndex."
           REFERENCE
                     "Section 2.2, Counters, of RFC1333."
           ::= { pppLqrEntry 6 }
      --
      -- The PPP LQR Configuration table.
      --
      pppLqrConfigTable   OBJECT-TYPE
           SYNTAX    SEQUENCE OF PppLqrConfigEntry
           ACCESS    not-accessible
           STATUS    mandatory
           DESCRIPTION
                     "Table containing the LQR Configuration
                     parameters for the local PPP entity."
           ::= { pppLqr 2 }
      pppLqrConfigEntry   OBJECT-TYPE
           SYNTAX    PppLqrConfigEntry
           ACCESS    not-accessible
           STATUS    mandatory
           DESCRIPTION
                     "LQR configuration information for a particular
                     PPP link."
           INDEX     { ifIndex }
           ::= { pppLqrConfigTable 1 }
      PppLqrConfigEntry ::= SEQUENCE {
           pppLqrConfigPeriod
                INTEGER,
           pppLqrConfigStatus
                INTEGER
      }
      pppLqrConfigPeriod   OBJECT-TYPE
           SYNTAX    INTEGER(0..2147483647)
           ACCESS    read-write
           STATUS    mandatory
           DESCRIPTION
                     "The LQR Reporting Period that the local PPP
                     entity will attempt to negotiate with the
                     remote entity, in units of hundredths of a
                     second. Changing this object will have effect
                     when the link is next restarted."
           REFERENCE
                     "Section 2.5, Configuration Option Format, of
                     RFC1333."
           DEFVAL    { 0 }
           ::= { pppLqrConfigEntry 1 }
      pppLqrConfigStatus   OBJECT-TYPE
           SYNTAX    INTEGER {disabled (1), enabled (2)}
           ACCESS    read-write
           STATUS    mandatory
           DESCRIPTION
                     "If enabled(2) then the local node will attempt
                     to perform LQR negotiation with the remote
                     node. If disabled(1) then this negotiation is
                     not performed. In any event, the local node
                     will comply with any magic number negotiations
                     attempted by the remote node, per the PPP
                     specification. Changing this object will have
                     effect when the link is next restarted.
                     Setting this object to the value disabled(1)
                     has the effect of invalidating the
                     corresponding entry in the pppLqrConfigTable
                     object. It is an implementation-specific matter
                     as to whether the agent removes an invalidated
                     entry from the table. Accordingly, management
                     stations must be prepared to receive tabular
                     information from agents that corresponds to
                     entries not currently in use."
           REFERENCE
                     "Section 7.6, Magic Number, of RFC1331."
           DEFVAL    { enabled }
           ::= { pppLqrConfigEntry 2 }
      -- 4.3.  PPP LQR Extensions Group
      --
      -- The PPP LQR Extensions Group.
      -- Implementation of this group is optional.
      --
      -- The intent of this group is to allow external
      -- implementation of the policy mechanisms that
      -- are used to declare a link to be "bad" or not.
      --
      -- It is not practical to examine the MIB objects
      -- which are used to generate LQR packets since
      -- LQR policies tend to require synchronization of
      -- the values of all data used to determine Link
      -- Quality; i.e. the values of the relevant counters
      -- must all be taken at the same instant in time.
      --
      pppLqrExtnsTable   OBJECT-TYPE
           SYNTAX    SEQUENCE OF PppLqrExtnsEntry
           ACCESS    not-accessible
           STATUS    mandatory
           DESCRIPTION
                     "Table containing additional LQR information
                     for the local PPP entity."
           ::= { pppLqr 3 }
      pppLqrExtnsEntry   OBJECT-TYPE
           SYNTAX    PppLqrExtnsEntry
           ACCESS    not-accessible
           STATUS    mandatory
           DESCRIPTION
                     "Extended LQR information for a particular PPP
                     link. Assuming that this group has been
                     implemented, a PPP link will have an entry in
                     this table if and only if LQR Quality
                     Monitoring has been successfully negotiated for
                     said link."
           INDEX     { ifIndex }
           ::= { pppLqrExtnsTable 1 }
      PppLqrExtnsEntry ::= SEQUENCE {
           pppLqrExtnsLastReceivedLqrPacket
                OCTET STRING(SIZE(68))
      }
      pppLqrExtnsLastReceivedLqrPacket   OBJECT-TYPE
           SYNTAX    OCTET STRING(SIZE(68))
           ACCESS    read-only
           STATUS    mandatory
           DESCRIPTION
                     "This object contains the most recently
                     received LQR packet.  The format of the packet
                     is as described in the LQM Protocol
                     specificiation. All fields of the packet,
                     including the `save' fields, are stored in this
                     object.
                     The LQR packet is stored in network byte order.
                     The LAP-B and PPP headers are not stored in
                     this object; the first four octets of this
                     variable contain the Magic-Number field, the
                     second four octets contain the LastOutLQRs
                     field and so on. The last four octets of this
                     object contain the SaveInOctets field of the
                     LQR packet."
           REFERENCE
                     "Section 2.6, Packet Format, of RFC1333"
           ::= { pppLqrExtnsEntry 1 }
      -- 4.4.  PPP Tests
      -- The extensions to the interface table in RFC1229 define a
      -- table through which the network manager can instruct the
      -- managed object to perform various tests of the interface. This
      -- is the ifExtnsTestTable.
      -- The PPP MIB defines two such tests.
      -- 4.4.1.  PPP Echo Test
      -- The PPP Echo Test is defined as
           pppEchoTest    OBJECT IDENTIFIER ::= { pppTests 1 }
      -- Invoking this test causes a PPP Echo Packet to be sent on the
      -- line. ifExtnsTestResult returns success(2) if the echo
      -- response came back properly. It returns failed(7) if the
      -- response did not properly return. The definition of "proper"
      -- in this context is left to the discretion of the implementor.
      -- 4.4.2.  PPP Discard Test
      -- The PPP Discard Test is defined as
           pppDiscardTest OBJECT IDENTIFIER ::= { pppTests 2 }
      -- Invoking this test causes a PPP Discard Packet to be sent on
      -- the line. ifExtnsTestResult returns success(2) if the discard
      -- packet was successfully transmitted and failed(7) if an error
      -- was detected on transmission. The definition of "transmission
      -- error" in this context is left to the discretion of the
      -- implementor.
      END

Acknowledgements

This document was produced by the PPP working group. In addition to the working group, the author wishes to thank the following individuals for their comments and contributions:

      Bill Simpson -- Daydreamer
      Glenn McGregor -- Merit
      Jesse Walker -- DEC
      Chris Gunner -- DEC

Security Considerations

The PPP MIB affords the network operator the ability to configure and control the PPP links of a particular system. This represents a security risk.

These risks are addressed in the following manners:

  (1)  All variables which represent a significant security risk
       are placed in separate, optional, MIB Groups. As the MIB
       Group is the quantum of implementation within a MIB, the
       implementor of the MIB may elect not to implement these
       groups.
  (2)  The implementor may choose to implement the variables
       which present a security risk so that they may not be
       written, i.e., the variables are READ-ONLY. This method
       still presents a security risk, and is not recommended,
       in that the variables, specifically the PPP
       Authentication Protocols' variables, may be easily read.
  (3)  Using SNMPv2, the operator can place the variables into
       MIB views which are protected in that the parties which
       have access to those MIB views use authentication and
       privacy protocols, or the operator may elect to make
       these views not accessible to any party.  In order to
       facilitate this placement, all security-related variables
       are placed in separate MIB Tables. This eases the
       identification of the necessary MIB View Subtree.

References

[1] Rose M., and K. McCloghrie, "Structure and Identification of

   Management Information for TCP/IP-based internets", STD 16, RFC
   1155, Performance Systems International, Hughes LAN Systems, May
   1990.

[2] McCloghrie K., and M. Rose, Editors, "Management Information Base

   for Network Management of TCP/IP-based internets", STD 17, RFC
   1213, Performance Systems International, March 1991.

[3] Information processing systems - Open Systems Interconnection -

   Specification of Abstract Syntax Notation One (ASN.1),
   International Organization for Standardization, International
   Standard 8824, December 1987.

[4] Information processing systems - Open Systems Interconnection -

   Specification of Basic Encoding Rules for Abstract Notation One
   (ASN.1), International Organization for Standardization,
   International Standard 8825, December 1987.

[5] Rose, M., and K. McCloghrie, Editors, "Concise MIB Definitions",

   STD 16, RFC 1212, Performance Systems International, Hughes LAN
   Systems, March 1991.

[6] Rose, M., Editor, "A Convention for Defining Traps for use with

   the SNMP", RFC 1215, Performance Systems International, March
   1991.

[7] McCloghrie, K., "Extensions to the Generic-Interface MIB", RFC

   1229, Hughes LAN Systems, Inc., May 1991.

[8] Simpson, W., "The Point-to-Point Protocol for the Transmission of

   Multi-protocol Datagrams over Point-to-Point Links, RFC 1331,
   Daydreamer, May 1992.

[9] McGregor, G., "The PPP Internet Protocol Control Protocol", RFC

   1332, Merit, May 1992.
 [10] Baker, F., "Point-to-Point Protocol Extensions for Bridging", RFC
   1220, ACC, April 1991.
 [11] Lloyd, B., and W. Simpson, "PPP Authentication Protocols", RFC
   1334, L&A, Daydreamer, October 1992.
 [12] Simpson, W., "PPP Link Quality Monitoring", RFC 1333, Daydreamer,
   May 1992.
 [13] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple
   Network Management Protocol", STD 15, RFC 1157, SNMP Research,
   Performance Systems International, Performance Systems
   International, MIT Laboratory for Computer Science, May 1990.

Author's Address

Frank Kastenholz FTP Software, Inc. 2 High Street North Andover, Mass 01845 USA

Phone: (508) 685-4000 EMail: [email protected]