rfc1595.txt
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ifConnectorPresent Set to true(1).
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
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