RFC 5650
Definitions of Managed Objects for Very High Speed Digital Subscriber Line 2 (VDSL2)
Pages: 218
Proposed Standard
Proposed Standard
Part 1 of 10 – Pages 1 to 24
Network Working Group M. Morgenstern Request for Comments: 5650 ECI Telecom Ltd. Category: Standards Track S. Baillie U. Bonollo NEC Australia September 2009 Definitions of Managed Objects for Very High Speed Digital Subscriber Line 2 (VDSL2)Abstract
This document defines a Management Information Base (MIB) module for use with network management protocols in the Internet community. In particular, it describes objects used for managing parameters of the "Very High Speed Digital Subscriber Line 2 (VDSL2)" interface type, which are also applicable for managing Asymmetric Digital Subscriber Line (ADSL), ADSL2, and ADSL2+ interfaces. 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 and License Notice Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the BSD License.
Table of Contents
1. The Internet-Standard Management Framework ......................2 2. Overview ........................................................2 2.1. Relationship to Other MIBs .................................4 2.2. IANA Considerations ........................................7 2.3. Conventions Used in the MIB Module .........................7 2.4. Structure .................................................11 2.5. Persistence ...............................................13 2.6. Line Topology .............................................16 2.7. Counters, Interval Buckets, and Thresholds ................17 2.8. Profiles ..................................................19 2.9. Notifications .............................................23 3. Definitions ....................................................24 4. Implementation Analysis .......................................204 5. Security Considerations .......................................204 6. Acknowledgments ...............................................215 7. References ....................................................216 7.1. Normative References .....................................216 7.2. Informative References ...................................2171. The Internet-Standard Management Framework
For a detailed overview of the documents that describe the current Internet-Standard Management Framework, please refer to Section 7 of RFC 3410 [RFC3410]. Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. MIB objects are generally accessed through the Simple Network Management Protocol (SNMP). Objects in the MIB are defined using the mechanisms defined in the Structure of Management Information (SMI). This memo specifies a MIB module that is compliant to the SMIv2, which is described in STD 58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579], and STD 58, RFC 2580 [RFC2580]. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].2. Overview
This document defines a Management Information Base (MIB) module for use with network management protocols in the Internet community for the purpose of managing VDSL2, ADSL, ADSL2, and ADSL2+ lines.
The MIB module described in RFC 2662 [RFC2662] describes objects used for managing Asymmetric Bit-Rate DSL (ADSL) interfaces per [T1E1.413], [G.992.1], and [G.992.2]. These object descriptions are based upon the specifications for the ADSL Embedded Operations Channel (EOC) as defined in American National Standards Institute (ANSI) T1E1.413/1995 [T1E1.413] and International Telecommunication Union (ITU-T) G.992.1 [G.992.1] and G.992.2 [G.992.2]. The MIB module described in RFC 4706 [RFC4706] is a wider management model that includes, in addition to ADSL technology, the ADSL2 and ADSL2+ technologies per G.992.3, G.992.4, and G.992.5 ([G.992.3], [G.992.4], and [G.992.5], respectively). This document does not obsolete RFC 2662 [RFC2662] or RFC 4706 [RFC4706], but rather provides a more comprehensive management model that addresses the VDSL2 technology per G.993.2 ([G.993.2]) as well as ADSL, ADSL2, and ADSL2+ technologies. This document does not obsolete RFC 2662 [RFC2662] or RFC 4706 [RFC4706]. RFC 2662 is relevant only for managing modems that do not support any DSL technology other than ADSL (e.g., G.992.1 [G.992.1] and G.992.2 [G.992.2]) especially if the modems were produced prior to approval of ITU-T G.997.1 standard revision 3 [G.997.1]. RFC 4706 is more appropriate for managing modems that support ADSL2 technology variants (with or without being able to support the legacy ADSL). This document supports all ADSL, ADSL2, and VDSL2 standards, but it assumes a more sophisticated management model, which older modems (even ADSL2 ones) may not be able to support. The selection of the appropriate MIB module for any DSL modem is based on the ifType value it reports, as explained in the next section. The management framework for VDSL2 lines [TR-129] specified by the Digital Subscriber Line Forum (DSLF) has been taken into consideration. That framework is based on the ITU-T G.997.1 standard [G.997.1] and its amendment 1 [G.997.1-Am1]. Note that the management model, according to this document, does not allow managing VDSL technology per G.993.1 [G.993.1]. VDSL lines MUST be managed by RFC 3728 [RFC3728]. The MIB module is located in the MIB tree under MIB 2 transmission, as discussed in the MIB-2 Integration (RFC 2863 [RFC2863]) section of this document.
2.1. Relationship to Other MIBs
This section outlines the relationship of this MIB module with other MIB modules described in RFCs. Specifically, IF-MIB as defined in RFC 2863 [RFC2863] and ENTITY-MIB as defined in RFC 4133 [RFC4133] are discussed.2.1.1. Relationship with IF-MIB (RFC 2863)
2.1.1.1. General IF-MIB Integration
The VDSL2 Line MIB specifies the detailed objects of a data interface. As such, it needs to integrate with RFC 2863 [RFC2863]. The IANA has assigned the following ifTypes, which may be applicable for VDSL2 lines as well as for ADSL, ADSL2, and ADSL2+ lines: IANAifType ::= TEXTUAL-CONVENTION ... SYNTAX INTEGER { ... channel(70), -- Channel adsl(94), -- Asymmetric Digital Subscriber Loop ... interleave(124), -- Interleaved Channel fast(125), -- Fast Channel ... adsl2plus(238), -- Asymmetric Digital Subscriber Loop Version 2, Version 2 Plus, and all variants vdsl2(251), -- Very High Speed Digital Subscriber Loop 2 ... } ADSL lines that are identified with ifType=adsl(94) MUST be managed with the MIB specified by RFC 2662. ADSL, ADSL2, and ADSL2+ lines identified with ifType=adsl2plus(238) MUST be managed with the MIB specified by RFC 4706 [RFC4706]. VDSL2, ADSL, ADSL2, and ADSL2+ lines identified with ifType=vdsl2(251) MUST be managed with the MIB specified by this document. In any case, the SNMP agent may use either ifType=interleave(124) or fast(125) for each channel, e.g., depending on whether or not it is capable of using an interleaver on that channel. It may use the ifType=channel (70) when all channels are capable of using an interleaver (e.g., for ADSL2 xTUs). Note that the ifFixedLengthGroup from RFC 2863 [RFC2863] MUST be supported and that the ifRcvAddressGroup does not apply to this MIB module.
2.1.1.2. Usage of ifTable
The MIB branch identified by ifType contains tables appropriate for the interface types described above. Most such tables extend the ifEntry table, and are indexed by ifIndex. For interfaces in systems implementing this MIB module, those table entries indexed by ifIndex MUST be persistent. The following objects are part of the mandatory ifGeneralInformationGroup in the Interfaces MIB [RFC2863], and are not duplicated in the VDSL2 Line MIB. ifIndex Interface index. ifDescr See interfaces MIB. ifType vdsl2(251), channel(70), interleave(124), or fast(125) ifSpeed Set as appropriate. ifPhysAddress This object MUST have an octet string with zero length. ifAdminStatus See interfaces MIB. ifOperStatus See interfaces MIB. ifLastChange See interfaces MIB. ifName See interfaces MIB. ifAlias See interfaces MIB. ifLinkUpDownTrapEnable Default to enabled(1). ifHighSpeed Set as appropriate. ifConnectorPresent Set as appropriate. ------------------------------------------------------------------- Figure 1: Use of ifTable Objects2.1.1.3. Usage of ifStackTable
Use of the ifStackTable to associate the entries for physical, fast, interleaved channels, and higher layers (e.g., ATM) is shown below. Use of the ifStackTable is necessary because configuration information is stored in profile tables associated with the physical-
layer ifEntry only. The channels' ifEntrys need the ifStackTable to find their associated physical-layer entry and thus their configuration parameters. The following example shows the ifStackTable entries for an xDSL line with a single channel that uses an ATM data path. HigherLayer LowerLayer ----------------------------- 0 ATM ATM XdslChannel XdslChannel XdslPhysical XdslPhysical 0 Figure 2: ifStackTable Entries for ATM Path over a Single xDSL Channel2.1.2. Relationship with the ENTITY-MIB (RFC 4133)
Implementation of the Entity MIB [RFC4133] is optional. It in no way alters the information required in the VDSL2 Line MIB, nor does it alter the relationship with IF-MIB. The Entity MIB introduces a standardized way of presenting the components of complex systems, such as a Digital Subscriber Line Access Multiplexer (DSLAM), that may contain multiple racks, shelves, line cards, and/or ports. The Entity MIB's main goal is to present these system components, their containment relationship, and mapping information with other MIBs such as the Interface MIB and the VDSL2 Line MIB. The Entity MIB is capable of supporting the local DSL termination unit. Thus, assuming the SNMP agent is in the DSLAM, the Entity MIB should include entities for the xTU-C in the entPhysicalTable. The MIB's entAliasMappingTable would contain mapping information identifying the 'ifIndex' object associated with each xTU-C. In case the SNMP agent is actually in the Customer Premise Equipment (CPE), the Entity MIB should include entities for the xTU-R in the entPhysicalTable. In this case, the MIB's entAliasMappingTable would contain mapping information identifying the 'ifIndex' object associated with each xTU-R. Also associating the relationship between the ifTable and Entity MIB, the entPhysicalTable contains an 'entPhysicalName' object, which approximates the semantics of the 'ifName' object from the Interface MIB.
2.2. IANA Considerations
A new ifType value (251) for Very High Speed Digital Subscriber Loop Version 2 has been allocated for the VDSL2-LINE-MIB module, to distinguish between ADSL lines that are managed with the RFC 2662 management model, ADSL/ADSL2 and ADSL2+ lines that are managed with the RFC 4706 [RFC4706] management model, and VDSL2/ADSL/ADSL2 and ADSL2+ lines that are managed with the model defined in this document. Also, the VDSL2-LINE-MIB module has been assigned a single object identifier (251) for its MODULE-IDENTITY. The IANA has allocated this object identifier in the transmission subtree. As performed in the past for the ADSL2-LINE-MIB module, the IANA has ensured that the allocated ifType value is the same as the allocated branch number in the transmission subtree.2.3. Conventions Used in the MIB Module
2.3.1. Naming Conventions
ADSL Asymmetric (bit rate) DSL ATM Asynchronous Transfer Mode atuc ADSL/ADSL2 or ADSL2+ line termination unit - central office atur ADSL/ADSL2 or ADSL2+ line termination unit - Remote site BER Bit Error Rate CO Central Office CPE Customer Premise Equipment CRC Cyclic Redundancy Check DELT Dual Ended Loop Test DMT Discrete Multitone DPBO Downstream PBO DRA Dynamic Rate Adaptation DSL Digital Subscriber Line/Loop DSLF DSL Forum EOC Embedded Operations Channel ES Errored Second FE Far-End (unit) FEBE Far-End Block Error FEC Forward Error Correction FFEC Far-End FEC IMA Inverse Multiplexing over ATM INP Impulse Noise Protection ISDN Integrated Services Digital Network LDSF Loop Diagnostic State Forced
LOF Loss Of Frame
LOS Loss Of Signal
LOSS LOS Seconds
LPR Loss of Power
NE Network Element or Near-End (unit)
NSC Highest transmittable subcarriers index
NSCds NSC for downstream transmission direction
NSCus NSC for upstream transmission direction
OLR Online Reconfiguration
PBO Power Backoff
PM Performance Monitoring
PMS-TC Physical Media Specific-Transmission Convergence
POTS Plain Old Telephone Service
PSD Power Spectral Density
PTM Packet Transfer Mode
QLN Quiet Line
RDI Remote Defect Indication
RFI Radio Frequency Interference
SEF Severely Errored Frame
SES Severely Errored Second
SNR Signal-to-Noise Ratio
TC Transmission Convergence (e.g., ATM sub layer)
TCM (TCM-ISDN) Time Compression Multiplexed ISDN
UAS Unavailable Seconds
U-C Loop interface-central office end
UPBO Upstream PBO
U-R Loop interface-remote side (i.e., subscriber end of the loop)
US0 Upstream band number 0
VDSL Very high speed DSL
VTU-O VDSL2 Transceiver Unit - central office or
Network Element End
VTU-R VTU at the remote site (i.e., subscriber end of the loop)
vtuc VDSL2 line termination unit - central office
vtur VDSL2 line termination unit - Remote site
xDSL Either VDSL2, ADSL, ADSL2 or ADSL2+
xTU-C ADSL/ADSL2/ADSL2+ or VDSL2 line termination unit -
central office
xTU-R ADSL/ADSL2/ADSL2+ or VDSL2 line termination unit -
Remote site
xTU A line termination unit; either an xTU-C or xTU-R
2.3.2. Textual Conventions
The following lists the textual conventions defined by VDSL2-LINE-TC- MIB in this document: o Xdsl2Unit o Xdsl2Direction o Xdsl2Band o Xdsl2TransmissionModeType o Xdsl2RaMode o Xdsl2InitResult o Xdsl2OperationModes o Xdsl2PowerMngState o Xdsl2ConfPmsForce o Xdsl2LinePmMode o Xdsl2LineLdsf o Xdsl2LdsfResult o Xdsl2LineBpsc o Xdsl2BpscResult o Xdsl2LineReset o Xdsl2LineProfiles o Xdsl2LineClassMask o Xdsl2LineLimitMask o Xdsl2LineUs0Disable o Xdsl2LineUs0Mask o Xdsl2SymbolProtection o Xdsl2SymbolProtection8
o Xdsl2MaxBer o Xdsl2ChInitPolicy o Xdsl2ScMaskDs o Xdsl2ScMaskUs o Xdsl2CarMask o Xdsl2RfiBands o Xdsl2PsdMaskDs o Xdsl2PsdMaskUs o Xdsl2Tssi o Xdsl2LastTransmittedState o Xdsl2LineStatus o Xdsl2ChInpReport o Xdsl2ChAtmStatus o Xdsl2ChPtmStatus o Xdsl2UpboKLF o Xdsl2BandUs o Xdsl2LinePsdMaskSelectUs o Xdsl2LineCeFlag o Xdsl2LineSnrMode o Xdsl2LineTxRefVnDs o Xdsl2LineTxRefVnUs o Xdsl2BitsAlloc o Xdsl2MrefPsdDs o Xdsl2MrefPsdUs
2.4. Structure
The MIB module is structured into the following MIB groups: o Line Configuration, Maintenance, and Status Group: This group supports MIB objects for configuring parameters for the VDSL2/ADSL/ADSL2 or ADSL2+ line and retrieving line status information. It also supports MIB objects for configuring a requested power state or initiating a Dual Ended Loop Test (DELT) process in the VDSL2/ADSL/ADSL2 or ADSL2+ line. It contains the following tables: - xdsl2LineTable - xdsl2LineSegmentTable - xdsl2LineBandTable o Channel Status Group: This group supports MIB objects for retrieving channel layer status information. It contains the following table: - xdsl2ChannelStatusTable o Subcarrier Status Group: This group supports MIB objects for retrieving the subcarrier layer status information, mostly collected by a Dual Ended Loop Test (DELT) process. It contains the following tables: - xdsl2SCStatusTable - xdsl2SCStatusBandTable - xdsl2SCStatusSegmentTable o Unit Inventory Group: This group supports MIB objects for retrieving Unit inventory information about units in VDSL2/ADSL/ADSL2 or ADSL2+ lines via the EOC. It contains the following table: - xdsl2LineInventoryTable o Current Performance Group: This group supports MIB objects that provide the current performance information relating to VDSL2/ADSL/ADSL2 and ADSL2+ line, unit, and channel levels. It contains the following tables:
- xdsl2PMLineCurrTable
- xdsl2PMLineInitCurrTable
- xdsl2PMChCurrTable
o 15-Minute Interval Performance Group:
This group supports MIB objects that provide historic performance
information relating to VDSL2/ADSL/ADSL2 and ADSL2+ line, unit,
and channel levels in 15-minute intervals. It contains the
following tables:
- xdsl2PMLineHist15MinTable
- xdsl2PMLineInitHist15MinTable
- xdsl2PMChHist15MinTable
o 1-Day Interval Performance Group:
This group supports MIB objects that provide historic performance
information relating to VDSL2/ADSL/ADSL2 and ADSL2+ line, unit,
and channel levels in 1-day intervals. It contains the following
tables:
- xdsl2PMLineHist1DayTable
- xdsl2PMLineInitHist1DayTable
- xdsl2PMChHist1DTable
o Configuration Template and Profile Group:
This group supports MIB objects for defining configuration
profiles for VDSL2/ADSL/ADSL2 and ADSL2+ lines and channels, as
well as configuration templates. Each configuration template is
comprised of a one-line configuration profile and one or more
channel configuration profiles. This group contains the following
tables:
- xdsl2LineConfTemplateTable
- xdsl2LineConfProfTable
- xdsl2LineConfProfModeSpecTable
- xdsl2LineConfProfModeSpecBandUsTable
- xdsl2ChConfProfileTable
o Alarm Configuration Template and Profile Group:
This group supports MIB objects for defining alarm profiles for
VDSL2/ADSL/ADSL2 and ADSL2+ lines and channels, as well as alarm
templates. Each alarm template is comprised of one line alarm
profile and one or more channel-alarm profiles. This group
contains the following tables:
- xdsl2LineAlarmConfTemplateTable
- xdsl2LineAlarmConfProfileTable
- xdsl2ChAlarmConfProfileTable
o Notifications Group:
This group defines the notifications supported for VDSL2/ADSL/
ADSL2 and ADSL2+ lines:
- xdsl2LinePerfFECSThreshXtuc
- xdsl2LinePerfFECSThreshXtur
- xdsl2LinePerfESThreshXtuc
- xdsl2LinePerfESThreshXtur
- xdsl2LinePerfSESThreshXtuc
- xdsl2LinePerfSESThreshXtur
- xdsl2LinePerfLOSSThreshXtuc
- xdsl2LinePerfLOSSThreshXtur
- xdsl2LinePerfUASThreshXtuc
- xdsl2LinePerfUASThreshXtur
- xdsl2LinePerfCodingViolationsThreshXtuc
- xdsl2LinePerfCodingViolationsThreshXtur
- xdsl2LinePerfCorrectedThreshXtuc
- xdsl2LinePerfCorrectedThreshXtur
- xdsl2LinePerfFailedFullInitThresh
- xdsl2LinePerfFailedShortInitThresh
- xdsl2LineStatusChangeXtuc
- xdsl2LineStatusChangeXtur
2.5. Persistence
All read-create objects and most read-write objects defined in this
MIB module SHOULD be stored persistently. The following is an
exhaustive list of these persistent objects:
xdsl2LineConfTemplate
xdsl2LineAlarmConfTemplate
xdsl2LineCmndConfPmsf
xdsl2LConfTempTemplateName
xdsl2LConfTempLineProfile
xdsl2LConfTempChan1ConfProfile
xdsl2LConfTempChan1RaRatioDs
xdsl2LConfTempChan1RaRatioUs
xdsl2LConfTempChan2ConfProfile
xdsl2LConfTempChan2RaRatioDs
xdsl2LConfTempChan2RaRatioUs
xdsl2LConfTempChan3ConfProfile
xdsl2LConfTempChan3RaRatioDs
xdsl2LConfTempChan3RaRatioUs
xdsl2LConfTempChan4ConfProfile
xdsl2LConfTempChan4RaRatioDs
xdsl2LConfTempChan4RaRatioUs
xdsl2LConfTempRowStatus
xdsl2LConfProfProfileName
xdsl2LConfProfScMaskDs
xdsl2LConfProfScMaskUs
xdsl2LConfProfVdsl2CarMask
xdsl2LConfProfRfiBandsDs
xdsl2LConfProfRaModeDs
xdsl2LConfProfRaModeUs
xdsl2LConfProfRaUsNrmDs
xdsl2LConfProfRaUsNrmUs
xdsl2LConfProfRaUsTimeDs
xdsl2LConfProfRaUsTimeUs
xdsl2LConfProfRaDsNrmDs
xdsl2LConfProfRaDsNrmUs
xdsl2LConfProfRaDsTimeDs
xdsl2LConfProfRaDsTimeUs
xdsl2LConfProfTargetSnrmDs
xdsl2LConfProfTargetSnrmUs
xdsl2LConfProfMaxSnrmDs
xdsl2LConfProfMaxSnrmUs
xdsl2LConfProfMinSnrmDs
xdsl2LConfProfMinSnrmUs
xdsl2LConfProfMsgMinUs
xdsl2LConfProfMsgMinDs
xdsl2LConfProfXtuTransSysEna
xdsl2LConfProfPmMode
xdsl2LConfProfL0Time
xdsl2LConfProfL2Time
xdsl2LConfProfL2Atpr
xdsl2LConfProfL2Atprt
xdsl2LConfProfProfiles
xdsl2LConfProfDpboEPsd
xdsl2LConfProfDpboEsEL
xdsl2LConfProfDpboEsCableModelA
xdsl2LConfProfDpboEsCableModelB
xdsl2LConfProfDpboEsCableModelC
xdsl2LConfProfDpboMus
xdsl2LConfProfDpboFMin
xdsl2LConfProfDpboFMax
xdsl2LConfProfUpboKL
xdsl2LConfProfUpboKLF
xdsl2LConfProfUs0Mask
xdsl2LConfProfRowStatus
xdsl2LConfProfXdslMode
xdsl2LConfProfMaxNomPsdDs
xdsl2LConfProfMaxNomPsdUs
xdsl2LConfProfMaxNomAtpDs
xdsl2LConfProfMaxNomAtpUs
xdsl2LConfProfMaxAggRxPwrUs
xdsl2LConfProfPsdMaskDs
xdsl2LConfProfPsdMaskUs
xdsl2LConfProfPsdMaskSelectUs
xdsl2LConfProfClassMask
xdsl2LConfProfLimitMask
xdsl2LConfProfUs0Disabl
xdsl2LConfProfModeSpecRowStatus
xdsl2LConfProfXdslBandUs
xdsl2LConfProfUpboPsdA
xdsl2LConfProfUpboPsdB
xdsl2LConfProfModeSpecBandUsRowStatus
xdsl2ChConfProfProfileName
xdsl2ChConfProfMinDataRateDs
xdsl2ChConfProfMinDataRateUs
xdsl2ChConfProfMinResDataRateDs
xdsl2ChConfProfMinResDataRateUs
xdsl2ChConfProfMaxDataRateDs
xdsl2ChConfProfMaxDataRateUs
xdsl2ChConfProfMinDataRateLowPwrDs
xdsl2ChConfProfMaxDelayDs
xdsl2ChConfProfMaxDelayUs
xdsl2ChConfProfMinProtectionDs
xdsl2ChConfProfMinProtectionUs
xdsl2ChConfProfMaxBerDs
xdsl2ChConfProfMaxBerUs
xdsl2ChConfProfUsDataRateDs
xdsl2ChConfProfDsDataRateDs
xdsl2ChConfProfUsDataRateUs
xdsl2ChConfProfDsDataRateUs
xdsl2ChConfProfImaEnabled
xdsl2ChConfProfMaxDelayVar
xdsl2ChConfProfInitPolicy
xdsl2ChConfProfRowStatus
xdsl2LAlarmConfTempTemplateName
xdsl2LAlarmConfTempLineProfile
xdsl2LAlarmConfTempChan1ConfProfile
xdsl2LAlarmConfTempChan2ConfProfile
xdsl2LAlarmConfTempChan3ConfProfile
xdsl2LAlarmConfTempChan4ConfProfile
xdsl2LAlarmConfTempRowStatus
xdsl2LineAlarmConfProfileName
xdsl2LineAlarmConfProfileXtucThresh15MinFecs
xdsl2LineAlarmConfProfileXtucThresh15MinEs
xdsl2LineAlarmConfProfileXtucThresh15MinSes
xdsl2LineAlarmConfProfileXtucThresh15MinLoss
xdsl2LineAlarmConfProfileXtucThresh15MinUas
xdsl2LineAlarmConfProfileXturThresh15MinFecs
xdsl2LineAlarmConfProfileXturThresh15MinEs
xdsl2LineAlarmConfProfileXturThresh15MinSes
xdsl2LineAlarmConfProfileXturThresh15MinLoss
xdsl2LineAlarmConfProfileXturThresh15MinUas
xdsl2LineAlarmConfProfileThresh15MinFailedFullInt
xdsl2LineAlarmConfProfileThresh15MinFailedShrtInt
xdsl2LineAlarmConfProfileRowStatus
xdsl2ChAlarmConfProfileName
xdsl2ChAlarmConfProfileXtucThresh15MinCodingViolations
xdsl2ChAlarmConfProfileXtucThresh15MinCorrected
xdsl2ChAlarmConfProfileXturThresh15MinCodingViolations
xdsl2ChAlarmConfProfileXturThresh15MinCorrected
xdsl2ChAlarmConfProfileRowStatus
Note, also, that the interface indices in this MIB are maintained
persistently. View-based Access Control Model (VACM) data relating
to these SHOULD be stored persistently as well [RFC3410].
2.6. Line Topology
A VDSL2/ADSL/ADSL2 and ADSL2+ line consists of two units: atuc or
vtuc (a central office termination unit) and atur or vtur (a remote
termination unit). There are up to 4 channels (maximum number of
channels depends on the specific DSL technology), each carrying an
independent information flow, as shown in the figure below.
<-- Network Side Customer Side --> |<///////////// VDSL2/ADSL/ADSL2/ADSL2+ Span //////////////>| +-------+ +-------+ | |<---------------------1------------------->| | | atuc |<---------------------2------------------->| atur | | or |<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>| or | | vtuc |<---------------------3------------------->| vtuc | | |<---------------------4------------------->| | +-------+ +-------+ Key: <////> VDSL2/ADSL/ADSL2/ADSL2+ Span <~~~~> VDSL2/ADSL/ADSL2/ADSL2+ twisted-pair -1- Channel #1 carried over the line -2- Optional channel #2 carried over the line -3- Optional channel #3 carried over the line -4- Optional channel #4 carried over the line Figure 3: General Topology for a VDSL2/ADSL/ADSL2/ADSL2+ Line2.7. Counters, Interval Buckets, and Thresholds
2.7.1. Counters Managed
There are various types of counters specified in this MIB. Each counter refers either to the whole VDSL2/ADSL/ADSL2/ADSL2+ line, to one of the xTU entities, or to one of the bearer channels. o On the whole line level For full initializations, failed full initializations, short initializations, and for failed short initializations, there are event counters, current 15-minute and 0 to 96 15-minute history bucket(s) of "interval-counters", as well as current and 0 to 30 previous 1-day interval-counter(s). Each current 15-minute "failed" event bucket has an associated threshold notification. o On the xTU level For the LOS seconds, ES, SES, FEC seconds, and UAS, there are event counters, current 15-minute and 0 to 96 15-minute history bucket(s) of "interval-counters", as well as current and 0 to 30 previous 1-day interval-counter(s). Each current 15-minute event bucket has an associated threshold notification.
o On the bearer channel level
For the coding violations (CRC anomalies) and corrected blocks
(i.e., FEC events), there are event counters, current 15-minute
and 0 to 96 15-minute history bucket(s) of "interval-counters", as
well as current and 0 to 30 previous 1-day interval-counter(s).
Each current 15-minute event bucket has an associated threshold
notification.
2.7.2. Minimum Number of Buckets
Although it is possible to support up to 96 15-minute history buckets
of "interval-counters", systems implementing this MIB module SHOULD
practically support at least 16 buckets, as specified in ITU-T
G.997.1, paragraph #7.2.7.9.
Similarly, it is possible to support up to 30 previous 1-day
"interval-counters", but systems implementing this MIB module SHOULD
support at least 1 previous day bucket.
2.7.3. Interval Buckets Initialization
There is no requirement for an agent to ensure a fixed relationship
between the start of a 15-minute interval and any wall clock;
however, some implementations may align the 15-minute intervals with
quarter hours. Likewise, an implementation may choose to align 1-day
intervals with the start of a day.
Counters are not reset when an xTU is reinitialized, only when the
agent is reset or reinitialized (or under specific request outside
the scope of this MIB module).
2.7.4. Interval Buckets Validity
As in RFC 3593 [RFC3593] and RFC 2662 [RFC2662], in case the data for
an interval is suspect or known to be invalid, the agent MUST report
the interval as invalid. If the current 15-minute event bucket is
determined to be invalid, the element management system SHOULD ignore
its content and the agent MUST NOT generate notifications based upon
the value of the event bucket.
A valid 15-minute event bucket SHOULD usually count the events for
exactly 15 minutes. Similarly, a valid 1-day event bucket SHOULD
usually count the events for exactly 24 hours. However, the
following scenarios are exceptional:
1) For implementations that align the 15-minute intervals with
quarter hours and the 1-day intervals with start of a day, the
management system may still start the PM process not aligned with
the wall clock. Such a management system may wish to retrieve
even partial information for the first event buckets, rather than
declaring them all as invalid.
2) For an event bucket that suffered relatively short outages, the
management system may wish to retrieve the available PM outcomes,
rather than declaring the whole event bucket as invalid. This is
more important for 1-day event buckets.
3) An event bucket may be shorter or longer than the formal duration
if a clock adjustment was performed during the interval.
This MIB module allows supporting the exceptional scenarios described
above by reporting the actual Monitoring Time of a monitoring
interval. This parameter is relevant only for Valid intervals, but
is useful for these exceptional scenarios:
a) The management system MAY still declare a partial PM interval as
Valid and report the actual number of seconds the interval lasted.
b) If the interval was shortened or extended due to clock
corrections, the management system SHOULD report the actual number
of seconds the interval lasted, in addition to reporting that the
interval is Valid.
2.8. Profiles
As a managed node can handle a large number of xTUs, (e.g., hundreds
or perhaps thousands of lines), provisioning every parameter on every
xTU may become burdensome. Moreover, most lines are provisioned
identically with the same set of parameters. To simplify the
provisioning process, this MIB module makes use of profiles and
templates.
A configuration profile is a set of parameters that can be shared by
multiple entities. There is a configuration profile to address line-
level provisioning and another type of profile that addresses
channel-level provisioning parameters.
A configuration template is actually a profile-of-profiles. That is,
a template is comprised of one-line configuration profile and one or
more channel configuration profiles. A template provides the
complete configuration of a line. The same configuration can be
shared by multiple lines.
In a similar manner to the configuration profiles and templates, this MIB module makes use of templates and profiles for specifying the alarm thresholds associated with performance parameters. This allows provisioning multiple lines with the same criteria for generating threshold crossing notifications. The following paragraphs describe templates and profiles used in this MIB module.2.8.1. Configuration Profiles and Templates
o Line Configuration Profiles - Line configuration profiles contain line-level parameters for configuring VDSL2/ADSL/ADSL2 and ADSL2+ lines. They are defined in the xdsl2LineConfProfTable. The line configuration includes settings such as the specific VDSL2/ADSL/ADSL2 or ADSL2+ modes to enable on the respective line, power spectrum parameters, rate adaptation criteria, and SNR margin-related parameters. A subset of the line configuration parameters depends upon the specific xDSL Mode allowed (i.e., does the profile allow VDSL2, ADSL, ADSL2 and/or ADSL2+?) as well as what annex/annexes of the standard are allowed. This is the reason a line profile MUST include one or more mode-specific extensions. o Channel Configuration Profiles - Channel configuration profiles contain parameters for configuring bearer channels over the VDSL2/ ADSL/ADSL2 and ADSL2+ lines. They are sometimes considered as the service layer configuration of the VDSL2/ADSL/ADSL2 and ADSL2+ lines. They are defined in the xdsl2ChConfProfTable. The channel configuration includes issues such as the desired minimum and maximum rate on each traffic flow direction and impulse noise protection parameters. o Line Configuration Templates - Line configuration templates allow combining line configuration profiles and channel configuration profiles into a comprehensive configuration of the VDSL2/ADSL/ ADSL2 and ADSL2+ line. They are defined in the xdsl2LineConfTemplateTable. The line configuration template includes one index of a line configuration profile and one to four indices of channel configuration profiles. The template also addresses the issue of distributing the excess available data rate on each traffic flow
direction (i.e., the data rate left after each channel is
allocated a data rate to satisfy its minimum requested data rate)
among the various channels.
2.8.2. Alarm Configuration Profiles and Templates
o Line Alarm Configuration Profiles - Line-level Alarm configuration
profiles contain the threshold values for Performance Monitoring
(PM) parameters, counted either on the whole line level or on an
xTU level. Thresholds are required only for failures and
anomalies. For example, there are thresholds for failed
initializations and LOS seconds, but not for the aggregate number
of full initializations. These profiles are defined in the
xdsl2LineAlarmConfProfileTable.
o Channel Alarm Configuration Profiles - Channel-level Alarm
configuration profiles contain the threshold values for PM
parameters counted on a bearer channel level. Thresholds are
defined for two types of anomalies: corrected blocks and coding
violations. These profiles are defined in the
xdsl2ChAlarmConfProfileTable.
o Line Alarm Configuration Templates - Line Alarm configuration
templates allow combining line-level alarm configuration profiles
and channel-level alarm configuration profiles into a
comprehensive configuration of the PM thresholds for the VDSL2/
ADSL/ADSL2 and ADSL2+ line. They are defined in the
xdsl2LineAlarmConfTemplateTable.
The line alarm configuration template includes one index of a
line-level alarm configuration profile and one to four indices of
channel-level alarm configuration profiles.
2.8.3. Managing Profiles and Templates
The index value for each profile and template is a locally unique,
administratively assigned name having the textual convention
'SnmpAdminString' (RFC 3411 [RFC3411]).
One or more lines may be configured to share parameters of a single
configuration template (e.g., xdsl2LConfTempTemplateName = 'silver')
by setting its xdsl2LineConfTemplate object to the value of this
template.
One or more lines may be configured to share parameters of a single
Alarm configuration template (e.g., xdsl2LAlarmConfTempTemplateName =
'silver') by setting its xdsl2LineAlarmConfTemplate object to the
value of this template.
Before a template can be deleted or taken out of service, it MUST be first unreferenced from all associated lines. Implementations MAY also reject template modification while it is associated with any line. Before a profile can be deleted or taken out of service, it MUST be first unreferenced from all associated templates. Implementations MAY also reject profile modification while it is referenced by any template. Implementations MUST provide a default profile whose name is 'DEFVAL' for each profile and template type. The values of the associated parameters will be vendor-specific unless otherwise indicated in this document. Before a line's templates have been set, these templates will be automatically used by setting xdsl2LineConfTemplate and xdsl2LineAlarmConfTemplate to 'DEFVAL' where appropriate. This default profile name, 'DEFVAL', is considered reserved in the context of profiles and templates defined in this MIB module. Profiles and templates are created, assigned, and deleted dynamically using the profile name and profile row status in each of the profile tables. If the implementation allows modifying a profile or template while it is associated with a line, then such changes MUST take effect immediately. These changes MAY result in a restart (hard reset or soft restart) of the units on the line. Network Elements MAY optionally implement a fallback line configuration template (see xdsl2LineConfFallbackTemplate). The fallback template will be tried if the xDSL2 line fails to operate using the primary template. If the xDSL2 line fails to operate using the fallback template, then the primary template should be retried. The xTU-C SHOULD continue to alternate between the primary and fallback templates until one of them succeeds.2.8.4. Managing Multiple Bearer Channels
The number of bearer channels is configured by setting the template objects xdsl2LConfTempChan1ConfProfile, xdsl2LConfTempChan2ConfProfile, xdsl2LConfTempChan3ConfProfile, and xdsl2LConfTempChan4ConfProfile and then assigning that template to a DSL line using the xdsl2LineConfTemplate object. When the number of bearer channels for a DSL line changes, the SNMP agent will automatically create or destroy rows in channel-related tables associated with that line. For example, when a DSL line is operating
with one bearer channel, there will be zero rows in channel-related
tables for channels two, three, and four. The SNMP agent MUST create
and destroy channel-related rows as follows:
o When the number of bearer channels for a DSL line changes to a
higher number, the SNMP agent will automatically create rows in
the xdsl2ChannelStatusTable and xdsl2PMChCurrTable tables for that
line.
o When the number of bearer channels for a DSL line changes to a
lower number, the SNMP agent will automatically destroy rows in
the xdsl2ChannelStatusTable,
xdsl2PMChCurrTable,xdsl2PMChHist15MinTable, and
xdsl2PMChHist1DTable tables for that line.
2.9. Notifications
The ability to generate the SNMP notifications coldStart/WarmStart
(per [RFC3418]), which are per agent (e.g., per Digital Subscriber
Line Access Multiplexer, or DSLAM, in such a device), and linkUp/
linkDown (per [RFC2863]), which are per interface (i.e., VDSL2/ADSL/
ADSL2 or ADSL2+ line) is required.
A linkDown notification MAY be generated whenever any of ES, SES, CRC
anomaly, LOS, LOF, or UAS events occur. The corresponding linkUp
notification MAY be sent when all link failure conditions are
cleared.
The notifications defined in this MIB module are for status change
(e.g., initialization failure) and for the threshold crossings
associated with the following events: full initialization failures,
short initialization failures, ES, SES, LOS seconds, UAS, FEC
seconds, FEC events, and CRC anomalies. Each threshold has its own
enable/threshold value. When that value is 0, the notification is
disabled.
The xdsl2LineStatusXtur and xdsl2LineStatusXtuc are bitmasks
representing all outstanding error conditions associated with the
xTU-R and xTU-C (respectively). Note that since the xTU-R status is
obtained via the EOC, this information may be unavailable in case the
xTU-R is unreachable via EOC during a line error condition.
Therefore, not all conditions may always be included in its current
status. Notifications corresponding to the bit fields in those two
status objects are defined.
Note that there are other status parameters that refer to the xTU-R (e.g., downstream line attenuation). Those parameters also depend on the availability of EOC between the central office xTU and the remote xTU. A threshold notification occurs whenever the corresponding current 15-minute interval error counter becomes equal to, or exceeds the threshold value. Only one notification SHOULD be sent per interval per interface. Since the current 15-minute counter is reset to 0 every 15 minutes, and if the condition persists, the notification may recur as often as every 15 minutes. For example, to get a notification whenever a "loss of" event occurs (but at most once every 15 minutes), set the corresponding threshold to 1. The agent will generate a notification when the event originally occurs. Note that the Network Management System, or NMS, may receive a linkDown notification, as well, if enabled (via ifLinkUpDownTrapEnable [RFC2863]). At the beginning of the next 15- minute interval, the counter is reset. When the first second goes by and the event occurs, the current interval bucket will be 1, which equals the threshold, and the notification will be sent again.
(page 24 continued on part 2)