Network Working Group K. McCloghrie Request for Comments: 1230 Hughes LAN Systems, Inc. R. Fox Synoptics, Inc. May 1991
IEEE 802.4 Token Bus MIB
Status of this Memo
This memo defines a MIB for the IEEE 802.4 Token Bus for use with the SNMP protocol. This memo is a product of the Transmission Working Group of the Internet Engineering Task Force (IETF). 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.
This memo defines an experimental portion of the Management Information Base (MIB) for use with network management protocols in TCP/IP-based internets. In particular, this memo defines managed objects used for managing subnetworks which use the IEEE 802.4 Token Bus technology described in 802.4 Token-Passing Bus Access Method and Physical Layer Specifications, IEEE Standard 802.4.
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.
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) [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.
Section 5 contains 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].
- the 802.4 Operational Table containing state and operational parameter information which is specific to 802.4 interfaces;
- the 802.4 Initialization Table containing the parameter information used by an 802.4 interface as the values to be assigned to its operational parameters upon initialization; and
- the 802.4 Statistics Table containing 802.4 interface statistics.
A managed system will have one entry in each of these tables for each of its 802.4 interfaces.
This memo also defines OBJECT IDENTIFIERs, some to identify 802.4 tests, for use with the ifExtnsTestTable defined in [11], and some to identify Token Bus interface Chip Sets, for use with the ifExtnsChipSet object defined in [11].
All objects defined in this memo are registered in a single subtree within the experimental namespace [3], and are for use with every interface which conforms to the IEEE 802.4 Token Bus Access Method [10]. At present, this applies to interfaces for which the ifType variable in the Internet-standard MIB [4,6] has the value:
iso88024-tokenBus(8)
For these interfaces, the value of the ifSpecific variable in the MIB-II [6] has the OBJECT IDENTIFIER value:
Two new datatypes, MacAddress and OctetTime, are introduced as textual conventions in this document. These textual conventions have NO effect on either the syntax nor the semantics of any managed object. Objects defined using these conventions are always encoded by means of the rules that define their primitive type. Hence, no changes to the SMI or the SNMP are necessary to accommodate these textual conventions which are adopted merely for the convenience of readers and writers in pursuit of the elusive goal of a concise and unambiguous specification.
A few objects are defined in this memo with "optional" status for the purpose of allowing experimentation to determine whether they are useful or not. If sufficient consensus is reached in the Internet community to result in a subsequent revision of this memo being placed in the Internet-standard MIB, then these optional objects will either be removed or become mandatory.
IMPORTS experimental FROM RFC1155-SMI OBJECT-TYPE FROM RFC-1212;
-- This MIB Module uses the extended OBJECT-TYPE macro as -- defined in [9].
dot4 OBJECT IDENTIFIER ::= { experimental 7 }
-- All representations of MAC addresses in this MIB Module -- use, as a textual convention (i.e. this convention does -- not affect their encoding), the data type:
MacAddress ::= OCTET STRING (SIZE (6)) -- a 6 octet -- address in the -- "canonical" order
Transmission Working Group [Page 4]
RFC 1230 IEEE 802.4 MIB May 1991
-- defined by IEEE -- 802.1a. -- 16-bit addresses, if needed, are represented by setting -- their upper 4 octets to all 0's, i.e., AAFF would be -- represented as 00000000AAFF.
-- This specification follows the 802.4 convention of -- specifying time intervals, which are dependent on the -- bandwidth of the media, in units of octet time. One -- octet time is the time taken to transmit eight bits. -- Representation of such time intervals in this MIB Module -- use, as a textual convention (i.e., this convention does -- not affect their encoding), the data type:
OctetTime ::= INTEGER -- the value of a time -- interval in units of octet -- time.
-- The 802.4 Operational Table
-- This table contains state and parameter information which -- is specific to 802.4 interfaces. It is mandatory that -- systems having 802.4 interfaces implement this table in -- addition to the generic interfaces table [4,6] and its -- generic extensions [11].
dot4Table OBJECT-TYPE SYNTAX SEQUENCE OF Dot4Entry ACCESS not-accessible STATUS mandatory DESCRIPTION "This table contains Token Bus interface parameters and state variables, one entry per 802.5 interface."
::= { dot4 1 }
dot4Entry OBJECT-TYPE SYNTAX Dot4Entry ACCESS not-accessible STATUS mandatory DESCRIPTION "A list of Token Bus status and operational parameter values for an 802.4 interface." INDEX { dot4IfIndex } ::= { dot4Table 1 }
dot4IfIndex OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION "The value of this object identifies the
Transmission Working Group [Page 6]
RFC 1230 IEEE 802.4 MIB May 1991
802.4 interface for which this entry contains management information. The value of this object for a particular interface has the same value as the ifIndex object, defined in [4,6], for the same interface." ::= { dot4Entry 1 }
dot4Options OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION "The optional parts of the 802.4 specification which are in use by this station. The options of the 802.4 specification are represented by the following values: 1 - Priority 2 - Request-With-Response The value of this object is given by the sum of the above representations for those options in use on this interface. The value zero indicates that no options are in use." ::= { dot4Entry 2 }
dot4State OBJECT-TYPE SYNTAX INTEGER { other(1), offline(2), outOfRing(3), enteringRing(4), inRing(5) } ACCESS read-only STATUS mandatory DESCRIPTION "The current state of the 802.4 interface. The value of other(1) is used if the state is unknown (e.g., due to an error condition)." ::= { dot4Entry 3 }
exitRing(3), reset(4), initialize(5) } ACCESS read-write STATUS mandatory DESCRIPTION "Setting this object causes the station to change the state of the interface as indicated by the specified value. An initialize(5) command causes the interfaceto load its operational parameters from its initialization parameters; the value of dot4InitInRingDesired determines whether the station tries to enter the logical ring immediately. Note that the 802.4 specification suggests a station remain Offline after a 'remote Network Management' reset(4), until a 'local Network Management' initialize(5) is performed. Setting this object to a value of no-op(1) has no effect. When read, this object always has the value no-op(1)." ::= { dot4Entry 4 }
dot4MacAddrLen OBJECT-TYPE SYNTAX INTEGER { sixteenBit(1), forty-eightBit(2) } ACCESS read-only STATUS mandatory DESCRIPTION "This object indicates the size of MAC addresses interpreted by this station." ::= { dot4Entry 5 }
dot4NextStation OBJECT-TYPE SYNTAX MacAddress ACCESS read-only STATUS mandatory DESCRIPTION "The MAC address of this station's successor in the logical ring." ::= { dot4Entry 6 }
Transmission Working Group [Page 8]
RFC 1230 IEEE 802.4 MIB May 1991
dot4PreviousStation OBJECT-TYPE SYNTAX MacAddress ACCESS read-only STATUS mandatory DESCRIPTION "The source MAC address of the last token addressed to this station." ::= { dot4Entry 7 }
dot4SlotTime OBJECT-TYPE SYNTAX OctetTime ACCESS read-only STATUS mandatory DESCRIPTION "The maximum time any station need wait for an immediate MAC-level response from another station. This value must the same in all stations on the 802.4 network." ::= { dot4Entry 8 }
dot4LastTokenRotTime OBJECT-TYPE SYNTAX OctetTime ACCESS read-only STATUS mandatory DESCRIPTION "The observed token rotation time for the last token rotation, timed from token arrival to token arrival. A value of zero indicates that the token is not rotating." ::= { dot4Entry 9 }
dot4HiPriTokenHoldTime OBJECT-TYPE SYNTAX OctetTime ACCESS read-only STATUS mandatory DESCRIPTION "The maximum duration for which a station can hold the token to transmit frames of access class 6 (if the priority option is implemented), or of any access class (if the priority option is not implemented)." ::= { dot4Entry 10 }
STATUS mandatory DESCRIPTION "If the priority scheme is being used, this value specifies a limit on how long a station can transmit frames at access class 4. The limit is measured from the time the station is able to start transmitting frames at this access class on one rotation, to the time it must stop transmitting frames at this access class on the next rotation. If the priority scheme is not being used, this object has the value 0." ::= { dot4Entry 11 }
dot4TargetRotTimeClass2 OBJECT-TYPE SYNTAX OctetTime ACCESS read-only STATUS mandatory DESCRIPTION "If the priority scheme is being used, this value specifies a limit on how long a station can transmit frames at access class 2. The limit is measured from the time the station is able to start transmitting frames at this access class on one rotation, to the time it must stop transmitting frames at this access class on the next rotation. If the priority scheme is not being used, this object has the value 0." ::= { dot4Entry 12 }
dot4TargetRotTimeClass0 OBJECT-TYPE SYNTAX OctetTime ACCESS read-only STATUS mandatory DESCRIPTION "If the priority scheme is being used, this value specifies a limit on how long a station can transmit frames at access class 0. The limit is measured from the time the station is able to start transmitting frames at this access class on one rotation, to the time it must stop transmitting frames at this access class on the next rotation. If the priority scheme is not being used,
Transmission Working Group [Page 10]
RFC 1230 IEEE 802.4 MIB May 1991
this object has the value 0." ::= { dot4Entry 13 }
dot4TargetRotTimeRingMaint OBJECT-TYPE SYNTAX OctetTime ACCESS read-only STATUS mandatory DESCRIPTION "A value used to limit the duration of a token rotation. If the duration of a token rotation exceeds this value, the station will not open the response window to solicit for a new successor." ::= { dot4Entry 14 }
dot4RingMaintTimerInitValue OBJECT-TYPE SYNTAX OctetTime ACCESS read-only STATUS mandatory DESCRIPTION "The value to which the dot4TargetRotTimeRingMaint is set, each time the station enters the ring. A large value will cause the station to solicit successors immediately upon entry to the ring; a value of zero will cause the station to defer this solicitation for at least one token rotation." ::= { dot4Entry 15 }
dot4MaxInterSolicitCount OBJECT-TYPE SYNTAX INTEGER (16..255) ACCESS read-only STATUS mandatory DESCRIPTION "The maximum number of consecutive token rotations without soliciting for a successor. If this count expires, the station opens the response window to solicit for a successor (providing the duration of the current token rotation has not exceeded dot4TargetRotTimeRingMaint). The least significant two bits of the count are determined randomly by the station on a per-use basis." ::= { dot4Entry 16 }
Transmission Working Group [Page 11]
RFC 1230 IEEE 802.4 MIB May 1991
dot4MaxRetries OBJECT-TYPE SYNTAX INTEGER (0..7) ACCESS read-only STATUS mandatory DESCRIPTION "The maximum number of retries of a Request-with-Response (RWR) frame. If the RWR option is not in use, this object has the value 0." ::= { dot4Entry 17 }
dot4MinPostSilencePreambLen OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION "The minimum number of octets of preamble on the first frame transmitted by this station after a period of 'transmitted' silence." ::= { dot4Entry 18 }
dot4StandardRevision OBJECT-TYPE SYNTAX INTEGER { rev2(2) } ACCESS read-only STATUS mandatory DESCRIPTION "The Revision number of the 802.4 standard implemented by this station." ::= { dot4Entry 19 }
-- 802.4 Initialization Table
-- This table contains the parameter information used by an -- 802.4 interface as the values to be assigned to its -- operational parameters upon initialization. It is -- mandatory that systems having 802.4 interfaces implement -- this table.
dot4InitTable OBJECT-TYPE SYNTAX SEQUENCE OF Dot4InitEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "This table contains Token Bus
Transmission Working Group [Page 12]
RFC 1230 IEEE 802.4 MIB May 1991
initialization parameters, one entry per 802.4 interface." ::= { dot4 2 }
dot4InitEntry OBJECT-TYPE SYNTAX Dot4InitEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A list of Token Bus initialization parameters for an 802.4 interface." INDEX { dot4InitIfIndex } ::= { dot4InitTable 1 }
dot4InitIfIndex OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION "The value of this object identifies the 802.4 interface for which this entry
Transmission Working Group [Page 13]
RFC 1230 IEEE 802.4 MIB May 1991
contains management information. The value of this object for a particular interface has the same value as the ifIndex object, defined in [4,6], for the same interface." ::= { dot4InitEntry 1 }
dot4InitSlotTime OBJECT-TYPE SYNTAX OctetTime ACCESS read-write STATUS mandatory DESCRIPTION "The value assigned to the object dot4SlotTime when the station is initialized." ::= { dot4InitEntry 2 }
dot4InitMaxInterSolicitCount OBJECT-TYPE SYNTAX INTEGER (16..255) ACCESS read-write STATUS mandatory DESCRIPTION "The value assigned to the object dot4MaxInterSolicitCount when the station is initialized." ::= { dot4InitEntry 3 }
dot4InitMaxRetries OBJECT-TYPE SYNTAX INTEGER (0..7) ACCESS read-write STATUS mandatory DESCRIPTION "The value assigned to the object dot4MaxRetries when the station is initialized." ::= { dot4InitEntry 4 }
dot4InitHiPriTokenHoldTime OBJECT-TYPE SYNTAX OctetTime ACCESS read-write STATUS mandatory DESCRIPTION "The value assigned to the object dot4HiPriTokenHoldTime when the station is initialized." ::= { dot4InitEntry 5 }
Transmission Working Group [Page 14]
RFC 1230 IEEE 802.4 MIB May 1991
dot4InitTargetRotTimeClass4 OBJECT-TYPE SYNTAX OctetTime ACCESS read-write STATUS mandatory DESCRIPTION "The value assigned to the object dot4TargetRotTimeClass4 when the station is initialized." ::= { dot4InitEntry 6 }
dot4InitTargetRotTimeClass2 OBJECT-TYPE SYNTAX OctetTime ACCESS read-write STATUS mandatory DESCRIPTION "The value assigned to the object dot4TargetRotTimeClass2 when the station is initialized." ::= { dot4InitEntry 7 }
dot4InitTargetRotTimeClass0 OBJECT-TYPE SYNTAX OctetTime ACCESS read-write STATUS mandatory DESCRIPTION "The value assigned to the object dot4TargetRotTimeClass0 when the station is initialized." ::= { dot4InitEntry 8 }
dot4InitTargetRotTimeRingMaint OBJECT-TYPE SYNTAX OctetTime ACCESS read-write STATUS mandatory DESCRIPTION "The value assigned to the object dot4TargetRotTimeRingMaint when the station is initialized." ::= { dot4InitEntry 9 }
dot4InitRingMaintTimerInitValue OBJECT-TYPE SYNTAX OctetTime ACCESS read-write STATUS mandatory DESCRIPTION "The value assigned to the object dot4RingMaintTimerInitValue when the station is initialized."
Transmission Working Group [Page 15]
RFC 1230 IEEE 802.4 MIB May 1991
::= { dot4InitEntry 10 }
dot4InitMinPostSilencePreambLen OBJECT-TYPE SYNTAX INTEGER ACCESS read-write STATUS mandatory DESCRIPTION "The value assigned to the object dot4MinPostSilencePreambLen when the station is initialized." ::= { dot4InitEntry 11 }
dot4InitInRingDesired OBJECT-TYPE SYNTAX INTEGER { inRing(1), outOfRing(2) } ACCESS read-write STATUS mandatory DESCRIPTION "This object determines whether the station will attempt to enter the logical ring immediately after initialization." ::= { dot4InitEntry 12 }
-- 802.4 Statistics Table
-- This table contains Token Bus statistics, one entry per -- 802.4 interface. It is mandatory that systems having -- 802.4 interfaces implement this table.
dot4StatsTable OBJECT-TYPE SYNTAX SEQUENCE OF Dot4StatsEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A table containing Token Bus statistics. All the statistics are defined using the syntax Counter as 32 bit wrap around counters. Thus, if an interface's hardware chip set maintains these statistics in 16-bit counters, then the agent must read the hardware's counters frequently enough to prevent loss of significance, in order to maintain a 32-bit counter in software." ::= { dot4 3 }
Transmission Working Group [Page 16]
RFC 1230 IEEE 802.4 MIB May 1991
dot4StatsEntry OBJECT-TYPE SYNTAX Dot4StatsEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "An entry containing the 802.4 statistics for a particular interface." INDEX { dot4StatsIfIndex } ::= { dot4StatsTable 1 }
dot4StatsIfIndex OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION "The value of this object identifies the 802.4 interface for which this entry contains management information. The value of this object for a particular
Transmission Working Group [Page 17]
RFC 1230 IEEE 802.4 MIB May 1991
interface has the same value as the ifIndex object, defined in [4,6], for the same interface." ::= { dot4StatsEntry 1 }
dot4StatsTokenPasses OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS optional DESCRIPTION "The number of times this station has passed the token." ::= { dot4StatsEntry 2 }
dot4StatsTokenHeards OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS optional DESCRIPTION "The number of tokens heard by this station." ::= { dot4StatsEntry 3 }
dot4StatsNoSuccessors OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of times the station could not find a successor while believing itself not the only station in the ring. This can signify a faulty transmitter condition in this station." ::= { dot4StatsEntry 4 }
dot4StatsWhoFollows OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of times the station has had to look for a new next station." ::= { dot4StatsEntry 5 }
dot4StatsTokenPassFails OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory
Transmission Working Group [Page 18]
RFC 1230 IEEE 802.4 MIB May 1991
DESCRIPTION "The number of times the station failed in passing the token to the next station." ::= { dot4StatsEntry 6 }
dot4StatsNonSilences OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of occurrences of non-silence followed by silence in which a start delimiter was not detected." ::= { dot4StatsEntry 7 }
dot4StatsFcsErrors OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of frames received with an incorrect FCS and the E-bit reset." ::= { dot4StatsEntry 8 }
dot4StatsEbitErrors OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of frames the station received with the E-bit set in the end delimiter." ::= { dot4StatsEntry 9 }
dot4StatsFrameFrags OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of occurrences of receiving a start delimiter followed by another start delimiter, an invalid symbol sequence or silence, without an intervening end delimiter." ::= { dot4StatsEntry 10 }
dot4StatsFrameTooLongs OBJECT-TYPE SYNTAX Counter
Transmission Working Group [Page 19]
RFC 1230 IEEE 802.4 MIB May 1991
ACCESS read-only STATUS mandatory DESCRIPTION "The number of frames that were received that were larger than the media's MTU." ::= { dot4StatsEntry 11 }
dot4StatsOverRuns OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of times a FIFO overrun was detected in the station." ::= { dot4StatsEntry 12 }
dot4StatsDupAddresses OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The number of times this station detected another station using the same MAC address." ::= { dot4StatsEntry 13 }
-- 802.4 Interface Tests
dot4Tests OBJECT IDENTIFIER ::= { dot4 5 }
-- The extensions to the interfaces table proposed in [11] -- define a table object, ifExtnsTestTable, through which a -- network manager can instruct an agent to test an interface -- for various faults. A test to be performed is identified -- (as the value of ifExtnsTestType) via an OBJECT IDENTIFIER.
-- When a test fails, the object ifExtnsTestCode, defined in -- [11], may contain a media-specific error-code. For 802.4 -- interfaces, the following is defined as the value of -- ifExtnsTestCode when a test fails because the modem could -- not be initialized:
-- The Full-Duplex Loop Back Test is a common test, defined -- in [11] as:
Transmission Working Group [Page 20]
RFC 1230 IEEE 802.4 MIB May 1991
-- -- testFullDuplexLoopBack -- -- Invoking this test on a 802.4 interface causes the -- interface to check the path from memory through the chip -- set's serial interface back to memory, thus checking the -- proper functioning of the transmit and receive machines -- of the token bus hardware. -- This test may only be invoked when the interface is -- the Offline state.
-- Invoking this test causes the interface to check the path -- from memory to the chip set's FIFO and back to memory. -- This test checks the hosts interface to the token bus -- hardware. This test may only be invoked when the -- interface is the Offline state.
-- Invoking this test causes the interface to check the path -- from memory through the chip set and out onto the network -- for external (e.g., at the head-end) loopback through the -- chip set to memory. This test checks the host's interface -- to the 802.4 network. This test is liable to cause -- serious disruption if invoked on an operational network.
-- 802.4 Hardware Chip Sets
dot4ChipSets OBJECT IDENTIFIER ::= { dot4 6 }
-- The extensions to the interfaces table proposed in [11] -- define an object, ifExtnsChipSet, with the syntax of -- OBJECT IDENTIFIER, to identify the hardware chip set in -- use by an interface. That definition specifies just -- one applicable object identifier: -- -- unknownChipSet -- -- for use as the value of ifExtnsChipSet when the specific -- chip set is unknown.
Transmission Working Group [Page 21]
RFC 1230 IEEE 802.4 MIB May 1991
-- -- This MIB defines the following for use as values of -- ifExtnsChipSet: -- for use as values of ifExtnsChipSet
[1] Cerf, V., "IAB Recommendations for the Development of Internet Network Management Standards", RFC 1052, NRI, April 1988.
[2] Cerf, V., "Report of the Second Ad Hoc Network Management Review Group", RFC 1109, NRI, August 1989.
[3] Rose M., and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based internets", RFC 1155, Performance Systems International, Hughes LAN Systems, May 1990.
[4] McCloghrie K., and M. Rose, "Management Information Base for Network Management of TCP/IP-based internets", RFC 1156, Hughes LAN Systems, Performance Systems International, May 1990.
[5] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple Network Management Protocol (SNMP), RFC 1157, SNMP Research, Performance Systems International, Performance Systems International, MIT Laboratory for Computer Science, May 1990.
[6] McCloghrie K., and M. Rose, Editors, "Management Information Base for Network Management of TCP/IP-based internets", RFC 1213, Performance Systems International, March 1991.
[7] Information processing systems - Open Systems Interconnection - Specification of Abstract Syntax Notation One (ASN.1), International Organization for Standardization, International
Transmission Working Group [Page 22]
RFC 1230 IEEE 802.4 MIB May 1991
Standard 8824, December 1987.
[8] 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.
[9] Rose, M., and K. McCloghrie, Editors, "Concise MIB Definitions", RFC 1212, Performance Systems International, Hughes LAN Systems, March 1991.
[10] Token-Passing Bus Access Method and Physical Layer Specifications, Institute of Electrical and Electronic Engineers, IEEE Standard 802.4, May 1988.
[11] McCloghrie, K., Editor, "Extensions to the Generic-Interface MIB", RFC 1229, Hughes LAN Systems, May 1991.