RFC 2266
Definitions of Managed Objects for IEEE 802.12 Repeater Devices
Pages: 56
Proposed Standard
Proposed Standard
Part 1 of 3 – Pages 1 to 11
Network Working Group J. Flick Request for Comments: 2266 Hewlett Packard Company Category: Standards Track January 1998 Definitions of Managed Objects for IEEE 802.12 Repeater Devices 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. Copyright Notice Copyright (C) The Internet Society (1998). All Rights Reserved. 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 managing network repeaters based on IEEE 802.12. Table of Contents 1. The SNMP Network Management Framework ...................... 2 1.1. Object Definitions ....................................... 2 2. Overview ................................................... 2 2.1. Repeater Management Model ................................ 3 2.2. MAC Addresses ............................................ 4 2.3. Master Mode and Slave Mode ............................... 4 2.4. IEEE 802.12 Training Frames .............................. 4 2.5. Structure of the MIB ..................................... 6 2.5.1. Basic Definitions ...................................... 7 2.5.2. Monitor Definitions .................................... 7 2.5.3. Address Tracking Definitions ........................... 7 2.6. Relationship to other MIBs ............................... 7 2.6.1. Relationship to MIB-II ................................. 7 2.6.1.1. Relationship to the 'system' group ................... 7 2.6.1.2. Relationship to the 'interfaces' group ............... 8 2.6.2. Relationship to the 802.3 Repeater MIB ................. 8
2.7. Mapping of IEEE 802.12 Managed Objects ................... 9 3. Definitions ................................................ 12 4. Acknowledgements ........................................... 53 5. References ................................................. 53 6. Security Considerations .................................... 54 7. Author's Address ........................................... 55 8. Full Copyright Statement ................................... 56 1. The SNMP Network Management Framework The SNMP Network Management Framework consists of several components. For the purpose of this specification, the applicable components of the Framework are the SMI and related documents [2, 3, 4], which define the mechanisms used for describing and naming objects for the purpose of management. The Framework permits new objects to be defined for the purpose of experimentation and evaluation. 1.1. Object Definitions Managed objects are accessed via a virtual information store, termed the Management Information Base (MIB). Objects in the MIB are defined using the subset of Abstract Syntax Notation One (ASN.1) [1] defined in the SMI [2]. 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. 2. Overview Instances of these object types represent attributes of an IEEE 802.12 repeater, as defined by Section 12, "RMAC Protocol" in IEEE Standard 802.12-1995 [6]. The definitions presented here are based on Section 13, "Layer management functions and services", and Annex C, "GDMO Specifications for Demand Priority Managed Objects" of IEEE Standard 802.12-1995 [6]. Implementors of these MIB objects should note that the IEEE document explicitly describes (in the form of Pascal pseudocode) when, where, and how various repeater attributes are measured. The IEEE document also describes the effects of repeater actions that may be invoked by manipulating instances of the MIB objects defined here.
The counters in this document are defined to be the same as those counters in IEEE Standard 802.12-1995, with the intention that the same instrumentation can be used to implement both the IEEE and IETF management standards. 2.1. Repeater Management Model The model used in the design of this MIB allows for a managed system to contain one or more managed 802.12 repeaters, and one or more managed 802.12 repeater ports. A repeater port may be thought of as a source of traffic into a repeater in the system. The vgRptrBasicPortTable contains entries for each physical repeater port in the managed system. An implementor may choose to separate these ports into "groups". For example, a group may be used to represent a field-replaceable unit, so that the port numbering may match the numbering in the hardware implementation. Note that this group mapping is recommended but optional. An implementor may choose to put all of the system's ports into a single group, or to divide the ports into groups that do not match physical divisions. Each group within the system is uniquely identified by a group number. Each port within a system is uniquely identified by a combination of group number and port number. The method of numbering groups and ports is implementation-specific. Both groups and ports may be sparsely numbered. In addition to the externally visible ports, some implementations may have internal ports that are not obvious to the end-user but are nevertheless sources of traffic into the repeater system. Examples include internal management ports, through which an agent communicates, and ports connecting to a backplane internal to the implementation. It is the decision of the implementor to select the appropriate group(s) in which to place internal ports. Managed repeaters in the system are represented by entries in the vgRptrInfoTable. There may be multiple repeaters in the managed system. They are uniquely identified by a repeater number. The method of numbering repeaters is implementation-specific. Each port will either be associated with one of the repeaters, or isolated (a so-called "trivial" repeater). The set of ports associated with a single repeater will be in the same contention domain, and will be participating in the same instance of the Demand Priority Access Method protocol. The mapping of ports to repeaters may be static or dynamic. A column in the vgRptrBasicPortTable, vgRptrPortRptrInfoIndex, indicates the repeater that the port is currently associated with. The method for assigning a port to a repeater is implementation-specific.
2.2. MAC Addresses All representations of MAC addresses in this MIB module are in "canonical" order defined by 802.1a, i.e., as if it were transmitted least significant bit first. This is true even if the repeater is operating in token ring framing mode, which requires MAC addresses to be transmitted most significant bit first. 2.3. Master Mode and Slave Mode In an IEEE 802.12 network, "master" devices act as network controllers to decide when to grant requesting end-nodes permission to transmit. These master devices may be repeaters, or other active controller devices such as switches. Devices which do not act as network controllers, such as end-nodes or passive switches, are considered to be operating in "slave" mode. An 802.12 repeater always acts in "master" mode on its local ports, which may connect to end nodes, switch or other device ports acting in "slave" mode, or lower-level repeaters in a cascade. It acts in "slave" mode on cascade ports, which may connect to an upper-level repeater in a cascade, or to switch or other device ports operating in "master" mode. 2.4. IEEE 802.12 Training Frames Training frames are special MAC frames that are used only during link initialization. Training frames are initially constructed by the device at the "lower" end of a link, which is the slave mode device for the link. The training frame format is as follows: +----+----+------------+--------------+----------+-----+ | DA | SA | Req Config | Allow Config | Data | FCS | +----+----+------------+--------------+----------+-----+ DA = destination address (six octets) SA = source address (six octets) Req Config = requested configuration (2 octets) Allow Config = allowed configuration (2 octets) Data = data (594 to 675 octets) FCS = frame check sequence (4 octets) Training frames are always sent with a null destination address. To pass training, an end node must use its source address in the source address field of the training frame. A repeater may use a non-null source address if it has one, or it may use a null source address.
The requested configuration field allows the slave mode device to
inform the master mode device about itself and to request
configuration options. The training response frame from the master
mode device contains the slave mode device's requested configuration
from the training request frame. The currently defined format of the
requested configuration field as defined in the IEEE Standard
802.12-1995 standard is shown below. Please refer to the most
current version of the IEEE document for a more up to date
description of this field. In particular, the reserved bits may be
used in later versions of the standard.
First Octet: Second Octet:
7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|v|v|v|r|r|r|r|r| |r|r|r|F|F|P|P|R|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
vvv: The version of the 802.12 training protocol with which
the training initiator is compliant. The current version
is 100. Note that because of the different bit ordering
used in IEEE and IETF documents, this value corresponds
to version 1.
r: Reserved bits (set to zero)
FF: 00 = frameType88023
01 = frameType88025
10 = reserved
11 = frameTypeEither
PP: 00 = singleAddressMode
01 = promiscuousMode
10 = reserved
11 = reserved
R: 0 = the training initiator is an end node
1 = the training initiator is a repeater
The allowed configuration field allows the master mode device to
respond with the allowed configuration. The slave mode device sets
the contents of this field to all zero bits. The master mode device
sets the allowed configuration field as follows:
First Octet: Second Octet:
7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|v|v|v|D|C|N|r|r| |r|r|r|F|F|P|P|R|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
vvv: The version of the 802.12 training protocol with which
the training responder is compliant. The current version
is 100. Note that because of the different bit ordering
used in IEEE and IETF documents, this value corresponds
to version 1.
D: 0 = No duplicate address has been detected.
1 = Duplicate address has been detected.
C: 0 = The requested configuration is compatible with the
network and the attached port.
1 = The requested configuration is not compatible with
the network and/or the attached port. In this case,
the FF, PP, and R bits indicate a configuration that
would be allowed.
N: 0 = Access will be allowed, providing the configuration
is compatible (C = 0).
1 = Access is not granted because of security
restrictions.
r: Reserved bits (set to zero).
FF: 00 = frameType88023 will be used.
01 = frameType88025 will be used.
10 = reserved
11 = reserved
PP: 00 = singleAddressMode
01 = promiscuousMode
10 = reserved
11 = reserved
R: 0 = Requested access as an end node is allowed.
1 = Requested access as a repeater is allowed.
Again, note that the most recent version of the IEEE 802.12 standard
should be consulted for the most up to date definition of the
requested configuration and allowed configuration fields.
The data field contains between 594 and 675 octets and is filled in
by the training initiator. The first 55 octets may be used for
vendor specific protocol information. The remaining octets are all
zeros. The length of the training frame combined with the
requirement that 24 consecutive training frames be exchanged without
error to complete training ensures that marginal links will not
complete training.
2.5. Structure of the MIB
Objects in this MIB are arranged into OID subtrees, each of which
contains a set of related objects within a broad functional category.
These subtrees are intended for organizational convenience ONLY, and
have no relation to the conformance groups defined later in the
document.
2.5.1. Basic Definitions The basic definitions include objects for managing the basic status and control parameters for each repeater within the managed system, for the port groups within the managed system, and for the individual ports themselves. 2.5.2. Monitor Definitions The monitor definitions include monitoring statistics for each repeater within the system and for individual ports. 2.5.3. Address Tracking Definitions This collection includes objects for tracking the MAC addresses of the DTEs attached to the ports within the system. Note that this MIB also includes by reference a collection of objects from the 802.3 Repeater MIB which may be used for mapping the topology of a network. These definitions are based on a technology which has been patented by Hewlett-Packard Company (HP). HP has granted rights to this technology to implementors of this MIB. See [8] and [9] for details. 2.6. Relationship to other MIBs 2.6.1. Relationship to MIB-II It is assumed that a repeater implementing this MIB will also implement (at least) the 'system' group defined in MIB-II [5]. 2.6.1.1. Relationship to the 'system' group In MIB-II, the 'system' group is defined as being mandatory for all systems such that each managed entity contains one instance of each object in the 'system' group. Thus, those objects apply to the entity even if the entity's sole functionality is management of repeaters. Note that all of the managed repeaters (i.e. entries in the vgRptrInfoTable) will normally exist within a single naming scope. Therefore, there will normally only be a single instance of each of the objects in the system group for the entire managed repeater system regardless of how many managed repeaters there are in the system.
2.6.1.2. Relationship to the 'interfaces' group In MIB-II, the 'interfaces' group is defined as being mandatory for all systems and contains information on an entity's interfaces, where each interface is thought of as being attached to a 'subnetwork'. (Note that this term is not to be confused with 'subnet' which refers to an addressing partitioning scheme used in the Internet suite of protocols.) This Repeater MIB uses the notion of ports on a repeater. The concept of a MIB-II interface has NO specific relationship to a repeater's port. Therefore, the 'interfaces' group applies only to the one (or more) network interfaces on which the entity managing the repeater sends and receives management protocol operations, and does not apply to the repeater's ports. This is consistent with the physical-layer nature of a repeater. An 802.12 repeater has an RMAC implementation, which acts as the repeater end of the Demand Priority Access Method, but does not contain a DTE MAC implementation, and does not pass packets up to higher-level protocol entities for processing. (When a network management entity is observing a repeater, it may appear as though the repeater is passing packets to a higher-level protocol entity. However, this is only a means of implementing management, and this passing of management information is not part of the repeater functionality.) 2.6.2. Relationship to the 802.3 Repeater MIB An IEEE 802.12 repeater can be configured to operate in either ethernet or token ring framing mode. This only affects the frame format and address bit order of the frames on the wire. An 802.12 network does not use the media access protocol for either ethernet or token ring. Instead, IEEE 802.12 defines its own media access protocol, the Demand Priority Access Method (DPAM). There is an existing standards-track MIB module for instrumenting IEEE 802.3 repeaters [7]. That MIB module is designed to instrument the operation of the repeater in a network implementing the 802.3 media access protocol. Therefore, much of that MIB does not apply to 802.12 repeaters. However, the 802.3 Repeater MIB also contains a collection of objects that may be used to map the topology of a network. These objects are contained in a separable OBJECT-GROUP, are not 802.3-specific, and are considered useful for 802.12 repeaters. In addition, the layer
management clause of the IEEE 802.12 specification includes similar functionality. Therefore, vendors of agents for 802.12 repeaters are encouraged to implement the snmpRptrGrpRptrAddrSearch OBJECT-GROUP defined in the 802.3 Repeater MIB. 2.7. Mapping of IEEE 802.12 Managed Objects IEEE 802.12 Managed Object Corresponding SNMP Object oRepeater .aCurrentFramingType vgRptrInfoCurrentFramingType .aDesiredFramingType vgRptrInfoDesiredFramingType .aFramingCapability vgRptrInfoFramingCapability .aMACAddress vgRptrInfoMACAddress .aRepeaterHealthState vgRptrInfoOperStatus .aRepeaterID vgRptrInfoIndex .aRepeaterSearchAddress SNMP-REPEATER-MIB - rptrAddrSearchAddress .aRepeaterSearchGroup SNMP-REPEATER-MIB - rptrAddrSearchGroup .aRepeaterSearchPort SNMP-REPEATER-MIB - rptrAddrSearchPort .aRepeaterSearchState SNMP-REPEATER-MIB - rptrAddrSearchState .aRMACVersion vgRptrInfoTrainingVersion .acRepeaterSearchAddress SNMP-REPEATER-MIB - rptrAddrSearchAddress .acResetRepeater vgRptrInfoReset .nRepeaterHealth vgRptrHealth .nRepeaterReset vgRptrResetEvent oGroup .aGroupCablesBundled vgRptrGroupCablesBundled .aGroupID vgRptrGroupIndex .aGroupPortCapacity vgRptrGroupPortCapacity oPort .aAllowableTrainingType vgRptrPortAllowedTrainType .aBroadcastFramesReceived vgRptrPortBroadcastFrames .aCentralMgmtDetectedDupAddr vgRptrMgrDetectedDupAddress .aDataErrorFramesReceived vgRptrPortDataErrorFrames .aHighPriorityFramesReceived vgRptrPortHighPriorityFrames .aHighPriorityOctetsReceived vgRptrPortHCHighPriorityOctets, or vgRptrPortHighPriorityOctets and vgRptrPortHighPriOctetRollovers .aIPMFramesReceived vgRptrPortIPMFrames .aLastTrainedAddress vgRptrAddrLastTrainedAddress .aLastTrainingConfig vgRptrPortLastTrainConfig
.aLocalRptrDetectedDupAddr vgRptrRptrDetectedDupAddress
.aMulticastFramesReceived vgRptrPortMulticastFrames
.aNormalPriorityFramesReceived vgRptrPortNormPriorityFrames
.aNormalPriorityOctetsReceived vgRptrPortHCNormPriorityOctets, or
vgRptrPortNormPriorityOctets and
vgRptrPortNormPriOctetRollovers
.aNullAddressedFramesReceived vgRptrPortNullAddressedFrames
.aOctetsInUnreadableFramesRcvd vgRptrPortHCUnreadableOctets, or
vgRptrPortUnreadableOctets and
vgRptrPortUnreadOctetRollovers
.aOversizeFramesReceived vgRptrPortOversizeFrames
.aPortAdministrativeState vgRptrPortAdminStatus
.aPortID vgRptrPortIndex
.aPortStatus vgRptrPortOperStatus
.aPortType vgRptrPortType
.aPriorityEnable vgRptrPortPriorityEnable
.aPriorityPromotions vgRptrPortPriorityPromotions
.aReadableFramesReceived vgRptrPortReadableFrames
.aReadableOctetsReceived vgRptrPortHCReadableOctets, or
vgRptrPortReadableOctets and
vgRptrPortReadOctetRollovers
.aSupportedCascadeMode vgRptrPortSupportedCascadeMode
.aSupportedPromiscMode vgRptrPortSupportedPromiscMode
.aTrainedAddressChanges vgRptrAddrTrainedAddressChanges
.aTrainingResult vgRptrPortTrainingResult
.aTransitionsIntoTraining vgRptrPortTransitionToTrainings
.acPortAdministrativeControl vgRptrPortAdminStatus
The following IEEE 802.12 managed objects have not been included in
the 802.12 Repeater MIB for the indicated reasons.
IEEE 802.12 Managed Object Disposition
oRepeater
.aGroupMap Can be determined by GetNext sweep
of vgRptrBasicGroupTable
.aRepeaterGroupCapacity Meaning is unclear in many
repeater implementations. For
example, some cards may have
daughter cards which make group
capacity change depending on the
cards installed. Meaning is also
unclear in a stackable
implementation. Also, since
groups are not required to be
numbered from 1..capacity, but may
be computed algorithmically or
related to Entity MIB indices,
this object was not considered
useful.
.aRepeaterHealthData Since the data is implementation
specific and non-interoperable,
it was not considered useful.
.aRepeaterHealthText Implementation experience with
similar object in 802.3 Rptr MIB
indicated it was not useful.
.acExecuteNonDisruptiveSelfTest Implementation experience with
similar object in 802.3 Rptr MIB
indicated it was not useful.
.nGroupMapChange Since aGroupMap was not included,
a notification of a change in that
object was not needed.
oGroup
.aPortMap Can be determined by GetNext sweep
of vgRptrBasicPortTable
.nPortMapChange Since aPortMap was not included,
a notification of a change in that
object was not needed.
oPort
.aMediaType This object is a function of the
Physical Media Dependent (PMD)
layer, which is defined
differently for each type of
network. For an 802.3 network,
.aMediaType corresponds to the PMD
definitions in the 802.3 MAU MIB.
For management of an 802.12
network, mapping of this object is
deferred to future work on an
802.12 PMD MIB which will include
both repeater and interface PMD
information and redundant link
support.
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