📄 rfc2662.txt
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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 adslLineMib. If ATU-C agent is implemented, the Entity MIB should include entities for the ATU-C in the entPhysicalTable. The MIB's entAliasMappingTable would contain mapping information identifying the 'ifIndex' object associated with each ATU-C. However, if ATU-R agent is implemented, the Entity MIB should include entities for the ATU-R in the entPhysicalTable. In this case, the MIB's entAliasMappingTable would contain mapping information identifying the 'ifIndex' object associated with each ATU-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.5. Conventions used in the MIB5.1 Naming Conventions A. Atuc/Atur are used for the ATU-C and ATU-R. In other RFCs, these are sometimes referred to as the Near End (Ne) and Far End (Fe) respectively, but not in this document. B. The terms, "transmit" and "receive", are from the perspective of the corresponding table's end of the line. For example, in the case of Fast channels, adslAtucChanConfFastMaxTxRate defines the "downstream" rate, while adslAturChanConfFastMaxTxRate defines the "upstream" rate for a particular channel. C. There are two possible channels: fast, and interleaved. None, one or both may be implemented on a particular ADSL Line. Figure 5 illustrates all possible operational configurations.Bathrick & Ly Standards Track [Page 7] RFC 2662 ADSL Line MIB August 1999 D. Lof, Lol, Los, Lpr mean Loss of Framing, Link, Signal, and Power, respectively. Lpr is used by T1E1, so it is used for consistency (rather than Lop). A Loss of Link condition is declared at the ATU-C if a Loss of Signal is not preceded by a `dying-gasp' message from the ATU-R. Note that Loss of Link is only supported by the ATU-C. E. ES means errored second. An Errored Second is any second containing one or more CRC anomaly, or one or more Los(s) or Severely Errored Frame (Sef) defect(s). F. A "block" is a physical-layer `data buffer' over which CRCs are calculated. For example, in DMT, the block is defined as the ADSL superframe. The block duration is 250 micro-seconds so the block length in bytes, as defined in adslAtu*ChanCrcBlockLength, varies with data rate. See Line Code Specific MIBs [11] [12] for more line code specific information. G. Atn means Attenuation, Psd is Power Spectral Density and Snr is Signal to Noise Ratio. H. LCS means line code specific, e.g., o DMT = Discrete MultiTone o CAP = Carrierless Amplitude and Phase modulation and o QAM = Quadrature Amplitude Modulation I. Vendor (in the Inventory objects) refers to the manufacturer of the ATU-C or ATU-R assembly, not the modem chip vendor. When in doubt, use the manufacturer of the smallest field replaceable unit (e.g., stand-alone modem box, plug-in board). J. RADSL - Rate Adaptive Asymmetric Digital Subscriber Loop5.2 Structure The MIB has multiple parallel tables. There are tables for: o line - common attributes o atuc and atur statusBathrick & Ly Standards Track [Page 8] RFC 2662 ADSL Line MIB August 1999 o atuc and atur performance - Current and up to 96 buckets of 15 min performance history - Current and Previous 1-day bucket performance history o profiles - configuration parameters and alarm parameters There are separate tables for Physical and Channel layers. Since their attributes are similar, only one set of "channel" tables are defined to be used for both fast and interleaved channels. The corresponding ifType gives the proper interpretation for that ifEntry. It is intented that Line Code Specific MIBs be located under adslLCSMib. These MIBs will be defined in separate modules. There could have been fewer tables by combining the ATU-C and ATU-R information into shared tables. However, the tables are more easily read when there are two identical sets of data. The figure below lists the five possible ADSL operational configurations. (indicated by the value of the adslLineType). In all configurations, the physical line interface entry will exist. However, the existence of the ADSL channel varies in each case, as shown below. Table Phys Fast Interleaved ___________________________________________________________ No Channels (1) | Y | | | Fast Only (2) | Y | Y | | Interleaved Only (3) | Y | | Y | Fast or Interleaved (4) | Y | Y | Y | Fast and Interleaved (5) | Y | Y | Y | Figure 5: ADSL Operational configurations NOTE: In (4), channel exists of either Fast or Interleaved type, but not both. The Manager may select the type of channel to be used. Depending on which operation configuration exists, some or all ADSL MIB tables could be supported, as shown in below. See Conformance Statements for more information on which objects are mandatory.Bathrick & Ly Standards Track [Page 9] RFC 2662 ADSL Line MIB August 1999 Table Phys Fast Interleaved ___________________________________________________________ adslLineTable | Y | | | adslAtucPhysTable | Y | | | adslAturPhysTable | Y | | | adslAtucChanTable | | Y | Y | adslAturChanTable | | Y | Y | adslAtucPerfDataTable | Y | | | adslAturPerfDataTable | Y | | | adslAtucIntervalTable | Y | | | adslAturIntervalTable | Y | | | adslAtucChanPerfDataTable | | Y | Y | adslAturChanPerfDataTable | | Y | Y | adslAtucChanIntervalTable | | Y | Y | adslAturChanIntervalTable | | Y | Y | Figure 6: Use of ADSL MIB Tables with various ifIndex values NOTE: The adslLineConfProfileTable and adslLineAlarmConfProfileTable will be present for all scenarios. See Profile Section of this document for implementation details such as profile creation, assignment, and indexing.5.2.1 Structure of Conformance Groups The MIB is organized to cover both ends of the ADSL line, ATU-C and ATU-R. Objects defined can be categorized into two groups: the ATU-C group which provides objects that are supported by ATU-C agents and the ATU-R group which provides objects that are supported by ATU-R agents. These two groups are defined by the conformance section of the MIB. All objects defined in the MIB module are supported by the ATU-C agent and only portions of the objects are supported by the ATU-R agent. Figure 7 lists all tables/objects that are supported by the ATU-R agent.Bathrick & Ly Standards Track [Page 10] RFC 2662 ADSL Line MIB August 1999 Table Objects _______________________________________________________ adslLineTable adslLineCoding adslAtucPhysTable adslAtucInvVendorID adslAtucInvVersionNumber adslAtucCurrStatus (Partial) adslAtucCurrOutputPwr adslAtucCurrAttainableRate adslAturPhysTable all are supported adslAtucChanTable all except adslAtucChanCrcBlockLength are supported adslAtucPerfDataTable all except adslAtucPerfLols,adslAtucPerfLprs adslAtucPerfCurr15MinLols, adslAtucPerfCurr15MinLprs, adslAtucPerfCurr1DayLols, adslAtucPerfCurr1DayLprs, adslAtucPerfPrev1DayLols and adslAtucPerfPrev1DayLprs are supported adslAturPerfDataTable all are supported adslAtucIntervalTable adslAtucIntervalLofs adslAtucIntervalLoss adslAtucIntervalESs adslAtucIntervalInits adslAtucIntervalValidData adslAturIntervalTable all are supported adslAtucChanPerfDataTable all are supported adslAturChanPerfDataTable all are supported adslAtucChanIntervalTable all are supported adslAturChanIntervalTable all are supported adslLineConfProfileTable not supported adslLineAlarmConfProfileTable all are supported except adslAtucThresh15MinLols and adslAtucThresh15MinLprs -------------------------------------------------------------------- Figure 7: MIB Tables and Objects Supported by the ATU-R AgentBathrick & Ly Standards Track [Page 11] RFC 2662 ADSL Line MIB August 1999 All traps supported by the ATU-R agent are also listed: adslAtucPerfLofsThreshTrap adslAtucPerfLossThreshTrap adslAtucPerfESsThreshTrap adslAtucRateChangeTrap adslAturPerfLofsThreshTrap adslAturPerfLossThreshTrap adslAturPerfLprsThreshTrap adslAturPerfESsThreshTrap adslAturRateChangeTrap5.3 Counters, Interval Buckets and Thresholds For physical-level ES, Los, Lof, Lol, Lpr and line initialization attempts, there are event counters, current 15-minute and one (up to 96) 15-minute history bucket(s) of "interval-counters", as well as current and previous 1-day interval-counters. Each physical-layer current 15-minute event bucket has threshold trap. At the channel level, there are counters for total received blocks, received-and-corrected blocks, received-but-uncorrectable blocks, and transmitted blocks. There are the same set of 15-minute and 1-day buckets as at the physical-layer. There is no requirement for an agent to ensure fixed relationship between the start of a fifteen minute and any wall clock; however some implementations may align the fifteen minute intervals with quarter hours. Likewise, an implementation may choose to align one day intervals with start of a day. Separate tables are provided for the 96 interval-counters. They are indexed by {ifIndex, AdslAtu*IntervalNumber}. Counters are not reset when an ATU-C or ATU-R is reinitialized, only when the agent is reset or reinitialized (or under specific request outside the scope of this MIB). The 15-minute event counters are of type PerfCurrentCount and PerfIntervalCount. The 1-day event counters are of type AdslPerfCurrDayCount and AdslPerfPrevDayCount. Both 15-minute and 1- day time elapsed counters are of type AdslPerfTimeElapsed.Bathrick & Ly Standards Track [Page 12] RFC 2662 ADSL Line MIB August 19995.4 Profiles As a managed node can handle a large number of ATU-Cs (e.g., hundreds or perhaps thousands of ADSL lines), provisioning every parameter on every ATU-C may become burdensome. In response, two MIB tables have been created to define ADSL equipment configuration data profiles, as well as a mechanism to associate the equipment to these profiles. Profile tables may be implemented in one of two ways, but not simultaneously: o MODE-I: Dynamic Profiles - one profile shared by one or multiple ADSL lines. o MODE-II: Static Profiles - one profile per ADSL physical line always.5.4.1 MODE-I : Dynamic Profiles Implementations using this mode will enable the manager to⌨️ 快捷键说明
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