rfc1595.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

AToM MIB Working Group                                          [Page 6]

RFC 1595                   SONET/SDH Objects                  March 1994


3.3.  Use of ifTable for SONET/SDH Paths

   Only the ifGeneralGroup needs to be supported.

          ifTable Object    Use for SONET/SDH Paths
          =========================================
           ifIndex           Interface index.

           ifDescr           SONET/SDH Path

           ifType            sonetPath(50)

           ifSpeed           set to speed of SONET/SDH path
                             (e.g., an STS-1 path has a
                             rate of 50112000 bps.)

           ifPhysAddress     Circuit Identifier or OCTET STRING of
                             zero length.

           ifAdminStatus     Supports read-only access.
                             The desired administrative status of the
                             interface.

           ifOperStatus      This object assumes the value down(2),
                             if the object sonetPathCurrentStatus has
                             any other value than sonetPathNoDefect(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 SONET/SDH path
                             in Mega-bits per second.

           ifConnectorPresent Set to false(2).











AToM MIB Working Group                                          [Page 7]

RFC 1595                   SONET/SDH Objects                  March 1994


3.4.  Use of ifTable for SONET/SDH VTs/VCs

   Only the ifGeneralGroup 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.

           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).











AToM MIB Working Group                                          [Page 8]

RFC 1595                   SONET/SDH Objects                  March 1994


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 ANSI
   T1M1.3/93-005R2 [11].  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 [18].  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 [18].  If the definition in this document
   does not match the definition in the ANSI T1M1.3/93-005R2 draft
   document, the implementer should follow the definition described in
   this document.

          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 work 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.

               An 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.

               An 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



AToM MIB Working Group                                          [Page 9]

RFC 1595                   SONET/SDH Objects                  March 1994


               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
               An 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.

               A 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 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
               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.



AToM MIB Working Group                                         [Page 10]

RFC 1595                   SONET/SDH Objects                  March 1994


               --  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.

               A STS-Path AIS failure is declared when the STS-Path AIS
               defect persists for 2.5 +/- 0.5 seconds.  A 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 an 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"



AToM MIB Working Group                                         [Page 11]

RFC 1595                   SONET/SDH Objects                  March 1994


               (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 five consecutive frames.

               --  Line RDI defect is terminated when any code other
               than "110" is detected in bits 6, 7, and 8 of the K2 byte
               in five consecutive frames.

               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 ANSI
               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 five contiguous
               frames.

               --  Removal of STS-Path Remote Defect Indication is
               detected by a "0" in bit 5 of the G1 byte in five
               contiguous frames.




AToM MIB Working Group                                         [Page 12]