📄 rfc2558.txt
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ifConnectorPresent Set to false(2). ifAlias The (non-volatile) alias name for this interface as assigned by the network manager.3.4. Use of ifTable for SONET/SDH VTs/VCs Only the ifGeneralInformationGroup needs to be supported. ifTable Object Use for SONET/SDH VTs/VCs =========================================== ifIndex Interface index. ifDescr SONET/SDH VT/VC ifType sonetVT(51) ifSpeed Set to speed of VT/VC (e.g., a VT1.5 has a rate of 1728000 bps.) ifPhysAddress Circuit Identifier or OCTET STRING of zero length. ifAdminStatus Supports read-only access. The desired administrative status of the interface.Tesink Standards Track [Page 7] RFC 2558 SONET/SDH Objects March 1999 ifOperStatus This object assumes the value down(2), if the object sonetVTCurrentStatus has any other value than sonetVTNoDefect(1). ifLastChange sysUpTime at the last change in ifOperStatus. ifName Textual name of the interface or an OCTET STRING of zero length. ifLinkUpDownTrapEnable Default value is disabled(2). Just read-only access may be supported. ifHighSpeed Set to rate of VT in Mega-bits per second. ifConnectorPresent Set to false(2). ifAlias The (non-volatile) alias name for this interface as assigned by the network manager.3.5. SONET/SDH Terminology The terminology used in this document to describe error conditions on a SONET circuit as monitored by a SONET system are from the T1.231 [22][31][35]. The terminology used in this document to describe error conditions on a SDH circuit as monitored by a SDH system are from the CCITT G.783 [29]. Only the SONET Performance Monitoring terminology is defined in this document. The definitions for SDH Performance Monitoring terms are similar but not identical, and they can be found in [29]. If the definition in this document does not match the definition in the T1.231 document, the implementer should follow the definition described in this document. In some cases other or additional references are used as compared with the ones cited above. This will be indicated in the text. Section Loss Of Frame Failure (Out of Frame Event, Severely Errored Frame Defect) An Out of Frame (OOF) event (or Severely Errored Frame defect) is the occurrence of four contiguous errored frame alignment words. A frame alignment word occupies the A1 and A2 bytes of an STS frame, and is defined in T1.105. The SEF defect is terminated when two contiguous error-free frame words are detected. Any implementation of the frame recovery circuitry which achieves realignment following an OOF within the 250 microsecond (two frames) interval implied by this definition is acceptable.Tesink Standards Track [Page 8] RFC 2558 SONET/SDH Objects March 1999 A Loss of Frame (LOF) defect is declared when an OOF/SEF defect persists for a period of 3 milliseconds. The LOF defect is terminated when the incoming signal remains continuously in- frame for a period of 1 ms to 3 ms. A LOF failure is declared when the LOF defect persists for a period of 2.5 +/- 0.5 seconds, except when an LOS defect or failure is present. The LOF failure is cleared when the LOS failure is declared, or when the LOF defect is absent for 10 +/- 0.5 seconds. Loss of Signal The Loss of Signal (LOS) defect is declared when no transitions are detected on the incoming signal (before descrambling). The LOS defect is detected upon observing 2.3 to 100 microseconds of no transitions. The LOS defect is cleared after a 125 microsecond interval (one frame) during which no LOS defect is detected. The LOS failure is declared when the LOS defect persists for a period of 2.5 +/- 0.5 seconds, or if LOS defect is present when the criteria for LOF failure declaration have been met. The LOS failure is cleared when the LOS defect is absent for a period of 10 +/- 0.5 seconds. Declaration of LOS failure clears any existing LOF failure. Clearing the LOS failure allows immediate declaration of the LOF failure if conditions warrant. STS-Path Loss of Pointer A Loss of Pointer (LOP) defect is declared when either a valid pointer is not detected in eight consecutive frames, or when eight consecutive frames are detected with the New Data Flag (NDF) set to "1001" without a valid concatenation indicator (see ANSI T1.105). A LOP defect is terminated when either a valid pointer with a normal NDF set to "0110", or a valid concatenation indicator is detected for three contiguous frames. Incoming STS-Path AIS shall not result in the declaration of a LOP defect. An STS-Path LOP failure is declared when the STS-Path LOP defect persists for a period of 2.5 +/- 0.5 seconds. A STS-Path LOP failure is cleared when the STS-Path LOP defect is absent for 10 +/- 0.5 seconds. VT Loss of Pointer A VT LOP defect is declared when either a valid pointer is not detected in eight consecutive VT superframes, or when eight consecutive VT superframes are detected with the NDF set to "1001" without a valid concatenation indicator. A VT LOP defectTesink Standards Track [Page 9] RFC 2558 SONET/SDH Objects March 1999 is terminated when either a valid pointer with a normal NDF set to "0110", or a valid concatenation indicator is detected for three contiguous VT superframes. Incoming VT-Path AIS shall not result in declaring a VT LOP defect. A VT LOP failure is declared when the VT LOP defect persists for 2.5 +/- 0.5 seconds. A VT LOP failure is cleared when the VT LOP defect is absent for 10 +/- 0.5 seconds. Line Alarm Indication Signal A Line Alarm Indication Signal (L-AIS) is defined in ANSI T1.105. The following criteria are specific to the L-AIS defect: -- Line AIS defect is detected as a "111" pattern in bits 6, 7, and 8 of the K2 byte in five consecutive frames. -- Line AIS defect is terminated when bits 6, 7, and 8 of the K2 byte do not contain the code "111" for five consecutive frames. A Line AIS failure is declared when the Line AIS defect persists for a period of 20.5 +/- 0.5 seconds. A Line AIS failure is cleared when the Line AIS defect is absent for 10 +/- 0.5 seconds. STS-Path Alarm Indication Signal The STS-Path Alarm Indication Signal (AIS) is defined in ANSI T1.105 as all ones in bytes H1, H2, and H3 as well as all ones in the entire STS SPE. The following criteria are specific to the STS-Path AIS defect: -- STS-Path AIS defect is detected as all ones in bytes H1 and H2 in three contiguous frames. -- The STS-Path AIS defect is terminated when a valid STS Pointer is detected with the NDF set to "1001" (inverted) for one frame, or "0110" (normal) for three contiguous frames. An STS-Path AIS failure is declared when the STS-Path AIS defect persists for 2.5 +/- 0.5 seconds. An STS-Path AIS failure is cleared when the STS-Path AIS defect is absent for 10 +/- 0.5 seconds. VT-Path Alarm Indication Signal The VT-Path Alarm Indication Signal (AIS) is only applicable for VTs in the floating mode of operation. VT-Path AIS is used to alert the downstream VT Path Terminating Entity (PTE) of anTesink Standards Track [Page 10] RFC 2558 SONET/SDH Objects March 1999 upstream failure. Upon detection of a failure, Line AIS, or STS-Path AIS, an STS PTE will generate downstream VT-Path AIS if the STS Synchronous Payload Envelope (SPE) is carrying floating VTs. VT-Path AIS is specified in ANSI T1.105 as all ones in bytes V1, V2, V3, and V4, as well as all ones in the entire VT SPE. The following criteria are specific to VT-Path AIS defect: -- VT-Path AIS defect is detected by a VT PTE as all ones in bytes V1 and V2 in three contiguous VT superframes. -- VT-Path AIS defect is terminated when valid VT pointer with a valid VT size is detected with the NDF set to "1001" (inverted) for one VT superframe, or "0110" (normal) for three contiguous VT superframes are detected. A VT-Path AIS failure is declared when the VT-Path AIS defect persists for 2.5 +/- 0.5 seconds. A VT-Path AIS failure is cleared when the VT-Path AIS defect is absent for 10 +/- 0.5 seconds. Line Remote Defect Indication Line Remote Defect Indication (RDI) (aka Line FERF) signal is the occurrence of a "110" pattern in bit positions 6, 7, and 8 of the K2 byte in STS-1 #1 of the STS-N signal. Line RDI is defined in ANSI T1.105. The following criteria are specific to Line RDI defect: -- Line RDI defect is a "110" code in bits 6, 7, and 8 of the K2 byte of in STS-1 #1 in x consecutive frames, where x = 5 [31][35] or 10 [35]. -- Line RDI defect is terminated when any code other than "110" is detected in bits 6, 7, and 8 of the K2 byte in x consecutive frames, where x = 5 [31][35] or 10 [35]. A Line Remote Failure Indication (RFI) failure is declared when the incoming Line RDI defects lasts for 2.5 +/- 0.5 seconds. The Line RFI failure is cleared when no Line RDI defects are detected for 10 +/- 0.5 seconds. STS-Path Remote Defect Indication STS-Path RDI (aka STS-Path FERF) signal shall be generated within 100 milliseconds by the STS PTE upon detection of an AIS or LOP defect. Transmission of the STS-Path RDI signal shall cease within 100 milliseconds when the STS PTE no longer detects STS-Path AIS or STS-Path LOP defect. The STS-Path RDI shall accurately report the presence or absence of STS-Path AIS or STS-Path LOP defects. STS-Path RDI defect is defined in ANSITesink Standards Track [Page 11] RFC 2558 SONET/SDH Objects March 1999 T1.105. The following requirements are specific to the STS-Path RDI defect: -- STS-Path RDI is detected by all STS PTEs. STS-Path RDI is detected by the upstream STS PTE as a "1" in bit five of the Path Status byte (G1) for x consecutive frames, where x = 5 [31] or 10 [35]. -- Removal of STS-Path Remote Defect Indication is detected by a "0" in bit 5 of the G1 byte in x consecutive frames, where x = 5 [31] or 10 [35]. An STS-Path Remote Failure Indication (RFI) failure is declared when the incoming STS-Path RDI defects lasts for 2.5 +/- 0.5 seconds. The STS-Path RFI failure is cleared when no STS-Path RDI defects are detected for 10 +/- 0.5 seconds. VT-Path Remote Defect Indication VT Path RDI (aka VT Path FERF) signal shall be generated within 100 milliseconds by the VT PTE upon detection of a VT-Path AIS or LOP defect. Transmission of the VT-Path RDI signal shall cease within 100 milliseconds when the VT PTE no longer detects VT-Path AIS or VT-Path LOP defect. The VT-Path RDI shall accurately report the presence or absence of VT-Path AIS or VT- Path LOP defects. VT-Path RDI defect is defined in ANSI T1.105. The following requirements are specific to VT-Path RDI defect: -- VT-Path RDI defect is the occurrence of a "1" in bit 4 of the VT-Path Overhead byte (V5) in x consecutive frames, where x = 5 [31] or 10 [35]. -- VT-Path RDI defect is terminated when a "0" is detected in bit 4 of the VT-Path Overhead byte (V5) for x consecutive frames, where x = 5 [31] or 10 [35]. A VT-Path Remote Failure Indication (RFI) (derived) failure is declared when the incoming VT-Path RDI defects lasts for 2.5 +/- 0.5 seconds. The VT-Path RFI failure is cleared when no VT-Path RDI defects are detected for 10 +/- 0.5 seconds. VT-Path Remote Failure Indication The VT-Path RFI signal is only required for the case of byte synch mapped DS1s where the DS1 frame bit is not mapped. The VT-Path RFI is specified in ANSI T1.105, where it is currently called VT path yellow. When provided, the VT-Path RFI signal is used to indicate the occurrence of far-end failures. When the VT-Path RFI is not provided, far-end failures are derived from local timing of the VT-Path RDI defect. The VT-Path RFI failureTesink Standards Track [Page 12] RFC 2558 SONET/SDH Objects March 1999 is declared within 5 ms of detecting the incoming VT-Path RFI Signal. The VT-Path Remote Failure Indication (RFI) failure is cleared within 50 ms of detecting the removal of the incoming VT-Path RFI signal. Coding Violation Coding Violations (CV) are Bit Interleaved Parity (BIP) errors that are detected in the incoming signal. CV counters are incremented for each BIP error detected. That is, each BIP-8 can detect up to eight errors per STS-N frame, with each error incrementing the CV counter. Section CVs shall be collected using the BIP-8 in the B1 byte located in the Section Overhead of STS-1 #1. Line CVs shall be collected using the BIP-8s in B2 bytes located in the Line Overhead of each STS-1 (since all CVs on an STS-N line are counted together, this is equivalent to counting each error in the BIP-8*N contained in the B2 bytes of the STS-N Line Overhead). Thus, on an STS-N signal, up to 8 x N CVs may occur in each frame. Path CVs shall be collected using the BIP-8 in the B3 byte of the STS-Path Overhead of the STS SPE. VT CVs shall be collected using the BIP-2 in the V5 overhead byte of the floating VT. Errored Seconds At each layer, an Errored Second (ES) is a second with one or more Coding Violations at that layer OR one or more incoming defects (e.g., SEF, LOS, AIS, LOP) at that layer has occurred. Severely Errored Seconds According to [22][31][32][34][35] at each layer, an Severely Errored Second (SES) is a second with x or more CVs at that layer, or a second during which at least one or more incoming defects at that layer has occurred. The values of x in RFC1595[30] were based on [22] and [32] (see Appendix B). These values have subsequently been relaxed in [31][34][35]. In addition, according to G.826 [33] SESs are measured as a percentage of errored blocks. To deal with these sets of definitions this memo defines an object sonetSESThresholdSet that determines the correct interpretation of SES. For backward compatibility, if this object is not implemented the interpretation of Appendix B shall apply. Otherwise, a more recent interpretation is suggested. An agent is not required to support all sets of definitions. Note that if a manager changes the value of this object all SES statistics collected prior to this change shall be invalidated.⌨️ 快捷键说明
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