RFC 3591
Definitions of Managed Objects for the Optical Interface Type
Network Working Group H-K. Lam Request for Comments: 3591 Lucent Technologies Category: Standards Track M. Stewart Dorado Software A. Huynh Cetus Networks September 2003 Definitions of Managed Objects for the Optical Interface Type 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 Notice Copyright (C) The Internet Society (2003). All Rights Reserved.Abstract
This memo defines a portion of the Management Information Base (MIB) for use with Simple Network Management Protocol (SNMP) in TCP/IP- based internets. In particular, it defines objects for managing Optical Interfaces associated with WavelengthDivision Multiplexing systems or characterized by the Optical Transport Network (OTN) in accordance with the OTN architecture defined in ITU-T Recommendation G.872. The MIB module defined in this memo can be used for performance monitoring and/or configuration of such optical interface.
Table of Contents
1. The Internet-Standard Management Framework ................. 2 2. Overview ................................................... 3 2.1. Use of the ifTable .................................. 3 2.2. Use of ifTable for OTN OTS/OMS Layer................. 8 2.3. Use of ifTable for OTN OChGroup Layer................ 9 2.4. Use of ifTable for OTN OCh Layer..................... 10 2.5. Use of ifStackTable.................................. 12 2.6. Optical Network Terminology ......................... 13 2.7. Tandem Connection Monitoring (TCM) .................. 20 3. Structure of the MIB........................................ 21 3.1. The optIfOTMn group.................................. 23 3.2. The optIfPerfMon group............................... 24 3.3. The optIfOTSn groups................................. 24 3.4. The optIfOMSn groups................................. 25 3.5. The optIfOChGroup groups............................. 26 3.6. The optIfOCh groups.................................. 27 3.7. The optIfOTUk groups................................. 28 3.8. The optIfODUk groups................................. 29 3.9. The optIfODUkT groups................................ 30 4. Object Definitions ......................................... 30 5. Security Considerations .................................... 167 6. Acknowledgments............................................. 169 7. References ................................................. 169 7.1. Normative References ................................. 169 7.2. Informative References ............................... 171 8. Intellectual Property Statement ............................ 171 9. Authors' Addresses ......................................... 172 10. Full Copyright Statement ................................... 1731. 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].
2. Overview
In this document, the term OTN (Optical Transport Network) system is used to describe devices that are compliant with the requirements specified in the ITU-T Recommendations G.872 [ITU-T G.872], G.709 [ITU-T G.709], G.798 [ITU-T G.798], G.874 [ITU-T G.874], and G.874.1 [ITU-T G.874.1]. The optical objects will be managed using the MIB II ifTable and ifStackTable. Additional tables will also be supported to monitor layer specific status and provide performance monitoring data. In the tables, some entries are required for OTN systems only. A Configuration (Config) table, Current Performance Monitoring (PM) table, and Interval PM table will be maintained for the OTSn, OMSn, OChGroup, and OCh layers on a source and sink trail termination basis. These tables will be linked to the ifTable by using the ifIndex that is associated with that layer. These objects are used when the particular media being used to realize an interface is an Optical Transport interface. At present, this applies to these values of the ifType variable in the Internet- standard MIB: opticalChannel (195), opticalChannelGroup (219), opticalTransport (196) The definitions contained herein are based on the OTN specifications in ITU-T G.872[ITU-T G.872], G.709 [ITU-T G.709], G.798[ITU-T G.798], G.874[ITU-T G.874], and G.874.1 [ITU-T G.874.1].2.1. Use of the ifTable
This section specifies how the MIB II interfaces group, as defined in RFC 2863 [RFC2863], is used for optical interfaces. Only the ifGeneralInformationGroup will be supported for the ifTable and the ifStackTable to maintain the relationship between the various layers. The OTN layers are managed in the ifTable using IfEntries that correlate to the layers depicted in Figure 1. For example, a DWDM device with an Optical Network Node Interface (ONNI) will have an Optical Transmission Section (OTS) physical layer, an Optical Multiplex Section (OMS) layer (transports multiple optical channels), and an Optical Channel (OCh) layer. There is a one to one relationship between the OMS and OTS layers. The OMS layer has fixed connectivity via the OTS and thus no connectivity flexibility at the OMS layer is supported.
A device with an ONNI that does not multiplex would consist of the OTS and OCh layers supporting a single channel. MIB-II (RFC 1213) [RFC1213], as amended and extended by RFC 3418 [RFC3418], RFC 2863 [RFC2863], and RFC 2864 [RFC2864], accommodates these cases through appropriate use of the system and interfaces groups. The system group names and describes the type of managed resource. The interfaces group defines which OTN layers exist and how these layers are configured and multiplexed. This is achieved by proper representation of OTN Layers as IfEntries as defined in RFC 2863 [RFC2863], as follows. In the following figures, opticalChannel and opticalTransport are abbreviated as och and otn respectively. _____________________ \ Path Data Unit |\ (ODUk) | \ _____________________| \ ______________________ | | | > Tandem Data Unit | | | | (ODUkT) | | OCh Layer | > n och IfEntries _____________________| | | | | |______________________| > Optical | /| | > Transport Unit | / | | | (OTUk) |/ | OMSn Layer | | _____________________/ | | | |______________________| | Sub-layers in | | > m otn IfEntries the OCh Layer | | | | OTSn Layer | | | | | |______________________| > Figure 1: OTN Layers Since the OMSn and OTSn layers have a one to one relationship, only one otn IfEntry is required to support these two layers. Therefore, each opticalChannel IfEntry may be mapped to m opticalTransport IfEntries, where m is greater than or equal to 1. Conversely, each opticalTransport entry may be mapped to n opticalChannel IfEntries, where n is greater than or equal to 1. There are implementations that have banded amplifers that operate on a group of optical channels separately (e.g., C and L band channels) before finally muxing them together and transporting them over a
physical layer. For such DWDM system implementations, it is important to have the ability to model each of the groups (or bands) with an ifIndex and measure the pre-OTN PM parameters for each band separately. The OTN layering, as described in Figure 1, can be extended to accomodate such implementations by introducing another layer called the OChGroup Layer. As an example, Figure 2 depicts the OTN layering of a DWDM system with 80 C-band and 80 L-band channels combined into their respective channel band groups before being muxed into the OMS and transported over the OTS. _________ ____________ |O|O| |O | |O |O | |O | > |C|C| |C | |C |C | |C | | |h|h|..|h | |h |h |..|h | > x och IfEntries |1|2| |80| |81|82| |160| | |_|_|__|__| |__|__|__|___| > | | | | > | | | | | |OChGroup1| | OChGroup2 | > n ochgroup IfEntries | | | | | |_________|__|____________| > | | > | | | | OMSn Layer | | | | | |_________________________| | | | > m otn IfEntries | | | | OTSn Layer | | | | | |_________________________| > Figure 2: OTN Layers for a Banded Configuration If an implementation does not wish to model the banded configuration, the OChGroup layer is absent and the OTN layering model degenerates to the description in Figure 1. In other words, when there is an amplifier that covers the whole band, the optIfOMSn objects should be used, rather than using the optIfOChGroup objects with a degenerate group that covers all channels. The design of the Optical Interface MIB provides the option to model an interface either as a single bidirectional object containing both sink and source functions or as a pair of unidirectional objects, one containing sink functions and the other containing source functions.
If the sink and source for a given protocol layer are to be modelled
as separate objects, then there need to be two ifTable entries, one
that corresponds to the sink and one that corresponds to the source,
where the directionality information is provided in the configuration
tables for that layer via the xxxDirectionality objects. The agent
is expected to maintain consistent directionality values between
ifStackTable layers (e.g., a sink must not be stacked in a 1:1 manner
on top of a source, or vice-versa), and all protocol layers that are
represented by a given ifTable entry are expected to have the same
directionality (i.e., instances of optIfOTSnDirectionality and
optIfOMSnDirectionality that correspond to a given ifIndex value must
have the same value, and instances of optIfOChDirectionality,
optIfOTUkDirectionality, and optIfODUkDirectionality that correspond
to a given ifIndex value must have the same value).
When separate ifTable entries are used for the source and sink
functions of a given physical interface, association between the two
uni-directional ifTable entries (one for the source function and the
other for the sink functions) should be provided. It is recommended
that identical ifName values are used for the two ifTable entries to
indicate such association. An implementation shall explicitly state
what mechanism is used to indicate the association, if ifName is not
used.
Example 1: Management of unterminated opticalChannel (och) using
passive optics
An OTN device connected with two adjacent nodes in a single fiber
ring that supports 10 wavelengths per fiber would have 2
opticalTransport IfEntries and 20 opticalChannel IfEntries, as
depicted in Figure 3. Thus 10 opticalChannel IfEntries are
stacked above the first opticalTransport IfEntry, and the other 10
opticalChannel IfEntries are stacked above the second
opticalTransport IfEntry. Note that the optical channels in this
example are un-terminated, and thus no OTUk objects will be
instantiated for these optical channels. The opticalChannel
IfEntries of one otn may be dropped/added from/to the OTN device
or cross-connected with the opticalChannel IfEntries of the other
otn. Cross-connection from a member of the first 10
opticalChannel IfEntries to a member of the second 10
opticalChannel IfEntries could be modelled by using a cross-
connect object, which is not yet defined in this version of the
MIB.
______________________ ______________________ | | | | | | | | | och1 | ... | och10 | | och11 | ... | och20 | |_______|______|_______| |_______|______|_______| | | | | | otn1 | | otn2 | |______________________| |______________________| ____________ | | ___________________\| OTN |__________________\ /| device | / |____________| Figure 3: Interface stacks when channels are unterminated Example 2: Management of terminated opticalChannel (och) interfaces An OTN device connected with two adjacent nodes in a single fiber ring that supports 10 wavelengths per fiber would have 2 opticalTransport IfEntries and 20 opticalChannel IfEntries, as depicted in Figure 4. Thus 10 opticalChannel IfEntries are stacked above the first opticalTransport IfEntry, and the other 10 opticalChannel IfEntries are stacked above the second opticalTransport IfEntry. As the optical channels in this example are terminated, OTUk objects and possibly ODUk objects will be instantiated for the terminated opticalChannel IfEntries. ______________________ ______________________ | | | | | | | | | och1 | ... | och10 | | och11 | ... | och20 | |_______|______|_______| |_______|______|_______| | | | | | otn1 | | otn2 | |______________________| |______________________| ____________ | | ___________________\| OTN |__________________\ /| device | / |____________| Figure 4: Interface stacks when channels are terminated Note that the two examples described above depict the interface stacks when the banded configuration is not modeled.
The exact configuration and multiplexing of the layers is maintained in the ifStackTable (RFC 2863) [RFC2863] and in the ifInvStackTable (RFC 2864) [RFC2864]; see section 2.5 for details.2.2. Use of ifTable for OTN OTS/OMS Layer
Only the ifGeneralInformationGroup needs to be supported. ifTable Object Use for combined OTN OTS/OMS Layer ===================================================================== ifIndex The interface index. ifDescr Optical Transport Network (OTN) Optical Transmission Section (OTS)/Optical Multiplex Section (OMS) ifType opticalTransport (196) ifSpeed Actual bandwidth of the interface in bits per second. If the bandwidth of the interface is greater than the maximum value of 4,294,967,295, then the maximum value is reported and ifHighSpeed must be used to report the interface's speed. ifPhysAddress An octet string with zero length. (There is no specific address associated with the interface.) ifAdminStatus The desired administrative status of the interface. Supports read-only access. ifOperStatus The operational status of the interface. The value lowerLayerDown(7) is not used, since there is no lower layer interface. This object is set to notPresent(6) if a component is missing, otherwise it is set to down(2) if either of the objects optIfOTSnCurrentStatus or optIfOMSnCurrentStatus indicates that any defect is present. ifLastChange The value of sysUpTime at the last change in ifOperStatus.
ifName Enterprise-specific convention (e.g., TL-1 AID)
to identify the physical or data entity
associated with this interface or an
OCTET STRING of zero length. The
enterprise-specific convention is intended to
provide the means to reference one or more
enterprise-specific tables.
ifLinkUpDownTrapEnable Default value is enabled(1). Supports
read-only access.
ifHighSpeed Actual bandwidth of the interface in Mega-bits
per second. A value of n represents a range of
'n-0.5' to 'n+0.499999'.
ifConnectorPresent Set to true(1).
ifAlias The (non-volatile) alias name for this interface
as assigned by the network manager.
2.3. Use of ifTable for OTN OChGroup Layer
Only the ifGeneralInformationGroup needs to be supported.
ifTable Object Use for OTN OChGroup Layer
=====================================================================
ifIndex The interface index.
ifDescr Optical Transport Network (OTN) Optical
Channel Group (OChGroup)
ifType opticalChannelGroup(219)
ifSpeed Current bandwidth of the interface in bits per
second. If the bandwidth of the interface is
greater than the maximum value of 4,294,967,295,
then the maximum value is reported and
ifHighSpeed must be used to report the
interface's speed.
ifPhysAddress A string that specifies the range of wavelengths
in the format of w1-w2, where w1 and w2 are the
lower and upper end of the wavelength range,
both in ASCII decimal digits expressed in
nanometers (e.g., 1350-1650)
ifAdminStatus The desired administrative status of the
interface. Supports read-only access.
ifOperStatus The operational status of the interface. This
object is set to lowerLayerDown(7) if the
ifOperStatus of its otn interface is down(2).
Otherwise, it is set to down(2) if the
amplifier for this band is unable to carry
traffic.
ifLastChange The value of sysUpTime at the last change in
ifOperStatus.
ifName Enterprise-specific convention (e.g., TL-1 AID)
to identify the physical or data entity
associated with this interface or an
OCTET STRING of zero length. The
enterprise-specific convention is
intended to provide the means to reference one
or more enterprise-specific tables.
ifLinkUpDownTrapEnable Default value is disabled(2). Supports
read-only access.
ifHighSpeed Current bandwidth of the interface in Mega-bits
per second. A value of n represents a range of
'n-0.5' to 'n+0.499999'.
ifConnectorPresent Set to false(2).
ifAlias The (non-volatile) alias name for this interface
as assigned by the network manager.
2.4. Use of ifTable for OTN OCh Layer
Only the ifGeneralInformationGroup needs to be supported.
ifTable Object Use for OTN OCh Layer
=====================================================================
ifIndex The interface index.
ifDescr Optical Transport Network (OTN) Optical
Channel (OCh)
ifType opticalChannel(195)
ifSpeed Current bandwidth of the interface in bits per
second. If the bandwidth of the interface is
greater than the maximum value of 4,294,967,295,
then the maximum value is reported and
ifHighSpeed must be used to report the
interface's speed.
ifPhysAddress A string of ASCII decimal digits containing the
wavelength of the optical channel, expressed
in nanometers (e.g., 1550).
ifAdminStatus The desired administrative status of the
interface. Supports read-only access.
ifOperStatus The operational status of the interface. This
object is set to lowerLayerDown(7) if the
ifOperStatus of its otn interface or of its
OChGroup interface is down(2).
Otherwise, it is set to down(2) if one or more
of the objects optIfOChCurrentStatus,
optIfOTUkCurrentStatus, optIfODUkTCurrentStatus,
and optIfODUkTtpCurrentStatus indicates
that any defect is present.
ifLastChange The value of sysUpTime at the last change in
ifOperStatus.
ifName Enterprise-specific convention (e.g., TL-1 AID)
to identify the physical or data entity
associated with this interface or an
OCTET STRING of zero length. The
enterprise-specific convention is
intended to provide the means to reference one
or more enterprise-specific tables.
ifLinkUpDownTrapEnable Default value is disabled(2). Supports
read-only access.
ifHighSpeed Current bandwidth of the interface in Mega-bits
per second. A value of n represents a range of
'n-0.5' to 'n+0.499999'.
ifConnectorPresent Set to false(2).
ifAlias The (non-volatile) alias name for this interface
as assigned by the network manager.
2.5. Use of ifStackTable
Use of the ifStackTable and ifInvStackTable to associate the opticalTransport and opticalChannel interface entries is best illustrated by the example shown in Figure 5. The example assumes an otn interface with ifIndex i that carries two multiplexed och interfaces with ifIndex values of j and k, respectively. The example shows that j and k are stacked above (i.e., multiplexed into) i. Furthermore, it shows that there is no layer lower than i and no layer higher than j and/or k. HigherLayer LowerLayer -------------------------- 0 j 0 k j i k i i 0 Figure 5: Use of ifStackTable for an OTN port Figure 6 illustrates an example for a banded configuration. The example assumes an otn interface with ifIndex i that carries two multiplexed och groups with ifIndex values u and v. An och group with ifIndex value u combines two och interfaces with ifIndex values of a and b. An och group with ifIndex value v combines two och interfaces with ifIndex values of c and d. The example show that a and b are stacked above (i.e., multiplexed into) u. Likewise, c and d are stacked above v. u and v are multiplexed into i. Furthermore, it shows that there is no layer lower than i and no layer higher than a, b, c, and/or d. It also shows that u has a and b as its higher layers, and v has c and d as its higher layers. HigherLayer LowerLayer -------------------------- 0 a 0 b 0 c 0 d a u b u c v d v u i v i i 0 Figure 6: Use of ifStackTable for an OTN port for a banded configuration
For the inverse stack table, it provides the same information as the interface stack table, with the order of the Higher and Lower layer interfaces reversed.2.6. Optical Network Terminology
The terminology used in this document to describe the layers of an optical network and the error conditions and performance monitoring parameters on an optical circuit as monitored by an optical system is listed below. These terms are defined in ITU-T Recommendations G.872 [ITU-T G.872], G.709 [ITU-T G.709], G.798 [ITU-T G.798], G.874 [ITU-T G.874], G.874.1 [ITU-T G.874.1], and G.806 [ITU-T G.806]. Brief definitions of some terms are also included here to facilitate the readability of this document. Degraded Threshold (DEGTHR) - G.806 A threshold level for declaring a performance monitoring (PM) Second (a time period of one second) to be bad. A PM Second is declared bad if the percentage of detected errored blocks in that second or the number of errored blocks in that Second is greater than or equal to DEGTHR. DEGM - G.806 A threshold level for declaring a Degraded Signal defect (dDEG). A dDEG shall be declared if DEGM consecutive bad PM Seconds are detected. Expected Destination Access Point Identifier (ExDAPI) - G.798 The Expected Destination Access Point Identifier (ExDAPI), provisioned by the managing system, to be compared with the TTI accepted at the overhead position of the sink for the purpose of checking the integrity of connectivity. Expected Source Access Point Identifier (ExSAPI) - G.798 The Expected Source Access Point Identifier (ExSAPI), provisioned by the managing system, to be compared with the TTI accepted at the overhead position of the sink for the purpose of checking the integrity of connectivity. Inter-Domain Interface (IrDI) - G.872 A physical interface that represents the boundary between two administrative domains. G.709 defines the requirements for the IrDI at the Network Node Interface (NNI). Intra-Domain Interface (IaDI) - G.872 A physical interface within an administrative domain.
Optical Channel Layer Network (OCh) - G.872
This layer network provides end-to-end networking of optical
channels for transparently conveying client information of
varying format (e.g., SDH STM-N, PDH 565 Mbit/s, cell based
ATM, etc.).
Optical Channel Data Unit Path Layer Network (ODUk) - G.709/Y.1331
This layer network provides functionality for the transport of
information structure consisting of the information payload
(OPUk) and the related overhead for management of an optical
channel.
Optical Channel Data Unit Tandem Connection Sub-Layer Network (ODUkT)
- G.709/Y.1331
This layer network is a sub-layer of the optical data unit
layer, which provides the capability for tandem connection
monitoring. One to six nested levels of monitoring are defined
for OTN.
Optical Channel Payload Unit (OPUk) - G.709/Y.1331
The OPUk is the information structure used to adapt client
information for transport over an optical channel. OPUk
capacities for k=1, k=2, k=3 are defined in ITU-T. The index
"k" is used to represent different versions of OPUk, ODUk and
OTUk. k=1 represents an approximate bit rate of 2.5 Gbit/s,
k=2 represents an approximate bit rate of 10 Gbit/s, and k=3
represents an approximate bit rate of 40 Gbit/s.
Optical Multiplex Section Layer Network (OMS) - G.872
This layer network provides functionality for networking of a
multi-wavelength optical signal. Note that a "multi-
wavelength" signal includes the case of just one optical
channel.
Optical Transport Module (OTM-n[r].m) - G.872
The OTM is the information structure that is transported across
an ONNI. The index n and m define the number of supported
wavelengths and bit rates at the interface.
Two OTM structures are defined: OTM with full functionality
(OTM-n.m) and OTM with reduced functionality (OTM-0.m & OTM-
nr.m).
The OTM-n.m consists of up to n multiplexed optical channels
and an OTM overhead signal to support the non-associated
overhead. The OTM-0 consists of a single optical channel
without a specific color assigned. The OTM-nr.m consists of up
to n multiplexed optical channels. Non associated overhead is
not supported.
Optical Transport Network (OTN) - G.872
A transport network bounded by optical channel access points.
The optical transport network layered structure is comprised of
the optical channel, optical multiplex section and optical
transmission section layer networks.
According to G.872, an OTN-compliant interface is an interface
of the optical transport network based on the architecture
defined in G.872, while an OTN-non-compliant interface is an
interface that does not comply with the interface
recommendations that will be defined for the optical transport
network based on the architecture defined in G.872.
Optical Transmission Section Layer Network (OTS) - G.872
This layer network provides functionality for transmission of
optical signals on optical media of various types.
Optical Channel Transport Unit Section Layer Network (OTUk) - G.709
The OTUk is the layer network that provides for the transport
of an ODUk over one or more optical channel link connections.
It consists of the optical channel data unit and OTUk related
overhead (FEC and overhead for management of an optical channel
link connection). It is characterized by its frame structure,
bit rate, and bandwidth.
Payload Type Mismatch (PLM)
The detection of a mismatch of payload type is based on a
comparison between the expected Payload Type signal,
provisioned via the management interface, and the received
Payload Type signal.
Trail Trace Identifier Transmitted (TxTI) - G.798
The Trail Trace Identifier (TTI) information, provisioned by
the managing system, to be placed in the TTI overhead position
of the source of a trail for transmission.
Trail Trace Identifier Accepted (AcTI) - G.798
The Trail Trace Identifier (TTI) information accepted from the
TTI overhead position at the sink of a trail.
Trail Trace Identifier Accepted Status (AcTIStatus) - G.798
The Status of the Trail Trace Identifier (TTI) accepted from
the TTI overhead position at the sink of a trail.
Trace Identifier Mismatch (TIM) - G.798
The detection of TIM is based on a comparison between the
expected Trial Trace Identifier (TTI), configured via the
management interface, and the received TTI.
Trace Identifier Mismatch Consequent Action Enabled (TimActEnabled) -
G.798
The Consequent Action function of TIM is disabled.
Trace Identifier Mismatch Detection Mode (TimDetMode) - G.798
The mode of detecting Trace Identifier Mismatch (TIM).
Possible modes are:
(1) off - no checking,
(2) SAPI - checking the SAPI only,
(3) DAPI - checking the DAPI only, and
(4) Both - checking both the SAPI and DAPI.
2.6.1. Defect Conditions
The following Defect conditions are defined in G.798 (as fault cause)
for OTN monitoring.
ais Alarm Indication Signal (AIS)
bdi Backward Defect Indication (BDI)
bdiO Backward Defect Indication - Overhead (BDI-O)
bdiP Backward Defect Indication - Payload (BDI-P)
deg Degraded (DEG)
lck Locked (LCK)
lof Loss of Frame (LOF)
lom Loss of Multi Frame
los Loss of Signal (LOS)
losO Loss of Signal - Overhead (LOS-O)
losP Loss of Signal - Payload (LOS-P)
oci Open Connection Indication (OCI)
plm Payload Mismatch (PLM)
ssf Server Signal Failure (SSF)
ssfO Server Signal Failure - Overhead (SSF-O)
ssfP Server Signal Failure - Payload (SSF-P)
tim Trace Identifier Mismatch (TIM)
The relationship of these conditions within a network layer and
between layers are described in G.798 [ITU-T G.798].
2.6.2. Performance Parameters
To facilitate identification of equipment and facilities that may require maintenance, it is necessary to monitor parameters such as optical power at each layer. The measurements are taken periodically, and a snapshot of the current value is also made available. More specifically, performance parameters at each layer are maintained for the current 15-minute interval, the current 24- hour interval, N previous 15-minute intervals where 4 <= N <= 96, and one previous 24-hour interval. Note that some of the previous interval data will be unavailable if the agent has restarted within the last 24 hours. There is no requirement for an agent to ensure a fixed relationship between the start of a 15-minute or 24-hour interval and any wall clock; however, some agents may align the 15-minute intervals with quarter hours and may align the 24-hour intervals with a particular hour of the day (e.g., 00:00 UTC). Note that some DWDM systems may also monitor the laser temperature of the equipment in addition to monitoring the optical power. However, industry opinions vary widely with respect to laser temperature monitoring, in particular regarding the benefit of the monitoring and which temperatures are to be monitored (i.e., all or only some of the pump lasers). Similarly, there are varying opinions regarding mid- stage power monitoring. Since no consensus was reached, it was decided that the laser temperature monitoring and mid-stage monitoring would not be standardized in the MIB. If an implementation would like to monitor these parameters, one could use a proprietary MIB or the ENTITY-SENSOR-MIB [RFC3433] to capture this information.
The sink-side monitoring points for the various layers are shown in Figure 7 below. OCh sink pre-OTN PM params | | OChGroup sink pre-OTN params | | | | OMSn sink pre-OTN PM params | | | | | | OTSn sink pre-OTN PM params | | | | V V V V /| ____/|_______/| /| / | \| . / |__________________/ |________________/ |_____ . \ | ____\ | \ | ____/|_______\| | \| ___\ | \| C-Band | Demux | \| | | | | ____/|_______/| | OSC \| . / |_____________| . \ | ____/|_______\| \| L-Band optical optical optical OSC Drop Filter rcvr (O/E) demux demux OCh OChGroup OMSn OTSn Figure 7: Sink-side pre-OTN monitoring points
The source-side monitoring points for the various layers are shown in Figure 8 below. OCh src pre-OTN PM params | | OChGroup src pre-OTN PM params | | | | OMSn src pre-OTN PM params | | | | | | OTSn src pre-OTN PM params | | | | V V V V |\ ___|\______|\ |\ | \ |/ . | \_________________| \______________| \______ . | / ___| / | / ----|/ | |/ __| / C-Band MUX | Mux | |/ | | | OSC ___|\______|\ | |/ . | \_____________| . | / ----|/ L-Band MUX optical optical optical OSC Add Filter xmtr mux mux (E/O) OCh OChGroup OMSn OTSn Figure 8: Source-side pre-OTN monitoring points Note that optical performance parameters are of type Integer32, rather than Counter32 or Gauge32, because it is possible for these objects to increase or decrease and to assume negative or positive values.
2.7. Tandem Connection Monitoring (TCM)
An ODUk termination can be provisioned to support (0..6) TCM levels. Each TCM field contains the following subfields: - Trail Trace Identifier (TTI) - Bit Interleaved Parity 8 (BIP8) - Backward Defect Indication (BDI) - Backward Error Indication (BEI) - Status bits indicating the presence of TCM overhead, Incoming AlignmentError, or a maintenance signal (STAT). The insertion of these subfields is controlled by: - optIfODUkTSourceMode or otnODUkTsinkMode The detection and corresponding action of these subfields are controlled by: - optIfODUkTTimDetMode - optIfODUkTTimActEnabled The TCM connection is used for monitoring the quality of an end to end connection or any segment, as illustrated in the example: TCM1 used for the end-to-end connection from A1 to A2. TCM2 used for segment B1-B2, then used again for segment B3-B4. TCM3-TCM6 these bytes are not in used in this example.
The TCM connection can be nested (B1-B2 is nested in A1-A2) or
cascaded (B1-B2 and B3-B4).
______ ______ ______ ______ ______
|TCM6| |TCM6| |TCM6| |TCM6| |TCM6|
|----| |----| |----| |----| |----|
|TCM5| |TCM5| |TCM5| |TCM5| |TCM5|
|----| |----| |----| |----| |----|
|TCM4| |TCM4| |TCM4| |TCM4| |TCM4|
|----| |----| |----| |----| |----|
|TCM3| |TCM3| |TCM3| |TCM3| |TCM3|
|----| |----| |----| |----| |----|
|TCM2| |TCM2| |TCM2| |TCM2| |TCM2|
|----| |----| |----| |----| |----|
|TCM1| |TCM1| |TCM1| |TCM1| |TCM1|
|----| |----| |----| |----| |----|
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
|\ |\ /| |\ /| /|
----> | \________| \_______/ |_________| \_____ / |______ / | ---->
| / | / \ | | / \ | \ |
|/ |/ \| |/ \| \|
TCM1: A1 <------------------------------------------------> A2
TCM2: B1 <-----> B2 B3 <-----> B4
3. Structure of the MIB
The managed Optical Networking interface objects are arranged into
the following groups of tables:
The optIfOTMn group handles the OTM information structure of an
optical interface.
optIfOTMnTable
The optIfPerfMon group handles the current 15-minute and 24-hour
interval elapsed time, as well as the number of 15-minute intervals
for all layers.
optIfPerfMonIntervalTable
The optIfOTSn groups handle the configuration and performance
monitoring information for OTS layers.
optIfOTSnConfigTable
optIfOTSnSinkCurrentTable
optIfOTSnSinkIntervalTable
optIfOTSnSinkCurDayTable
optIfOTSnSinkPrevDayTable
optIfOTSnSrcCurrentTable
optIfOTSnSrcIntervalTable
optIfOTSnSrcCurDayTable
optIfOTSnSrcPrevDayTable
The optIfOMSn groups handle the configuration and performance
information for OMS layers.
optIfOMSnConfigTable
optIfOMSnSinkCurrentTable
optIfOMSnSinkIntervalTable
optIfOMSnSinkCurDayTable
optIfOMSnSinkPrevDayTable
optIfOMSnSrcCurrentTable
optIfOMSnSrcIntervalTable
optIfOMSnSrcCurDayTable
optIfOMSnSrcPrevDayTable
The optIfOChGroup groups handle the configuration and performance
information for OChGroup layers.
optIfOChGroupConfigTable
optIfOChGroupSinkCurrentTable
optIfOChGroupSinkIntervalTable
optIfOChGroupSinkCurDayTable
optIfOChGroupSinkPrevDayTable
optIfOChGroupSrcCurrentTable
optIfOChGroupSrcIntervalTable
optIfOChGroupSrcCurDayTable
optIfOChGroupSrcPrevDayTable
The optIfOCh groups handle the configuration and performance
monitoring information for OCh layers.
optIfOChConfigTable
optIfOChSinkCurrentTable
optIfOChSinkIntervalTable
optIfOChSinkCurDayTable
optIfOChSinkPrevDayTable
optIfOChSrcCurrentTable
optIfOChSrcIntervalTable
optIfOChSrcCurDayTable
optIfOChSrcPrevDayTable
The optIfOTUk groups handle configuration information for OTUk.
optIfOTUkConfigTable
optIfGCC0ConfigTable
The optIfODUk groups handle configuration information for ODUk.
optIfODUkConfigTable
optIfODUkTtpConfigTable
optIfODUkPositionSeqTable
optIfODUkNimConfigTable
optIfGCC12ConfigTable
The optIfODUkT groups handle configuration information for ODUkT.
optIfODUkTConfigTable
optIfODUkTNimConfigTable
This memo does not define MIB objects for optical system cross-
connects. After a consensus is reached on definitions of the
interface MIB objects for optical systems (resulting from resolution
of discussions on the objects proposed in this memo), work can
progress on the definitions of tables to represent cross-connects
(e.g., OCh optical cross-connects and ODUk electrical cross-
connects).
3.1. The optIfOTMn group
3.1.1. optIfOTMnTable
This table contains the OTM structure information of an optical
interface.
3.2. The optIfPerfMon group
3.2.1. optIf Performance Monitoring Interval Table
This table applies to all performance monitoring on an NE. It records on a per-interface basis the elapsed time in the current 15- minute and 24-hour interval, as well as the total number of 15-minute intervals and the number of invalid 15-minute intervals.3.3. The optIfOTSn groups
3.3.1. optIfOTSn Configuration group
3.3.1.1. optIfOTSn Configuration Table
This table contains information on configuration of optIfOTSn interfaces, in addition to the information on such interfaces contained in the ifTable.3.3.2. optIfOTSn Pre-OTN PM group
3.3.2.1. optIfOTSn Source Current Table
This table contains information on current performance of optIfOTSn interfaces contained in the ifTable.3.3.2.2. optIfOTSn Source Interval Table
This table contains information on historic performance of optIfOTSn interfaces contained in the ifTable.3.3.2.3. optIfOTSn Source Current Day Table
This table contains a snapshot of information for the current 24-hour period for optIfOTSn interfaces contained in the ifTable.3.3.2.4. optIfOTSn Source Previous Day Table
This table contains a snapshot of information for the previous 24- hour period for optIfOTSn interfaces contained in the ifTable.3.3.2.5. optIfOTSn Sink Current Table
This table contains information on current performance of optIfOTSn interfaces contained in the ifTable.
3.3.2.6. optIfOTSn Sink Interval Table
This table contains information on historic performance of optIfOTSn interfaces contained in the ifTable.3.3.2.7. optIfOTSn Sink Current Day Table
This table contains a snapshot of information for the current 24-hour period for optIfOTSn interfaces contained in the ifTable.3.3.2.8. optIfOTSn Sink Previous Day Table
This table contains a snapshot of information for the previous 24- hour period for optIfOTSn interfaces contained in the ifTable.3.4. The optIfOMSn groups
3.4.1. optIfOMSn Configuration group
3.4.1.1. optIfOMSn Configuration Table
This table contains information on configuration of optIfOMSn interfaces, in addition to the information on such interfaces contained in the ifTable.3.4.2. optIfOMSn Pre-OTN PM group
3.4.2.1. optIfOMSn Source Current Table
This table contains information on current performance of optIfOMSn interfaces contained in the ifTable.3.4.2.2. optIfOMSn Source Interval Table
This table contains information on historic performance of optIfOMSn interfaces contained in the ifTable.3.4.2.3. optIfOMSn Source Current Day Table
This table contains a snapshot of information for the current 24-hour period for optIfOMSn interfaces contained in the ifTable.3.4.2.4. optIfOMSn Source Previous Day Table
This table contains a snapshot of information for the previous 24- hour period for optIfOMSn interfaces contained in the ifTable.
3.4.2.5. optIfOMSn Sink Current Table
This table contains information on current performance of optIfOMSn interfaces contained in the ifTable.3.4.2.6. optIfOMSn Sink Interval Table
This table contains information on historic performance of optIfOMSn interfaces contained in the ifTable.3.4.2.7. optIfOMSn Sink Current Day Table
This table contains a snapshot of information for the current 24-hour period for optIfOMSn interfaces contained in the ifTable.3.4.2.8. optIfOMSn Sink Previous Day Table
This table contains a snapshot of information for the previous 24- hour period for optIfOMSn interfaces contained in the ifTable.3.5. The optIfOChGroup groups
3.5.1. optIfOChGroup Configuration group
3.5.1.1. optIfOChGroup Configuration Table
This table contains information on configuration of optIfOChGroup interfaces, in addition to the information on such interfaces contained in the ifTable.3.5.2. optIfOChGroup Pre-OTN PM group
3.5.2.1. optIfOChGroup Source Current Table
This table contains information on current performance of optIfOChGroup interfaces contained in the ifTable.3.5.2.2. optIfOChGroup Source Interval Table
This table contains information on historic performance of optIfOChGroup interfaces contained in the ifTable.3.5.2.3. optIfOChGroup Source Current Day Table
This table contains a snapshot of information for the current 24-hour period for optIfOChGroup interfaces contained in the ifTable.
3.5.2.4. optIfOChGroup Source Previous Day Table
This table contains a snapshot of information for the previous 24- hour period for optIfOChGroup interfaces contained in the ifTable.3.5.2.5. optIfOChGroup Sink Current Table
This table contains information on current performance of optIfOChGroup interfaces contained in the ifTable.3.5.2.6. optIfOChGroup Sink Interval Table
This table contains information on historic performance of optIfOChGroup interfaces contained in the ifTable.3.5.2.7. optIfOChGroup Sink Current Day Table
This table contains a snapshot of information for the current 24-hour period for optIfOChGroup interfaces contained in the ifTable.3.5.2.8. optIfOChGroup Sink Previous Day Table
This table contains a snapshot of information for the previous 24- hour period for optIfOChGroup interfaces contained in the ifTable.3.6. The optIfOCh groups
3.6.1. optIfOCh Configuration group
3.6.1.1. optIfOCh Configuration Table
This table contains information on configuration of optIfOCh interfaces, in addition to the information on such interfaces contained in the ifTable.3.6.2. optIfOCh Pre-OTN PM group
3.6.2.1. optIfOCh Source Current Table
This table contains information on current performance of optIfOCh interfaces contained in the ifTable.3.6.2.2. optIfOCh Source Interval Table
This table contains information on historic performance of optIfOCh interfaces contained in the ifTable.
3.6.2.3. optIfOCh Source Current Day Table
This table contains a snapshot of information for the current 24-hour period for optIfOCh interfaces contained in the ifTable.3.6.2.4. optIfOCh Source Previous Day Table
This table contains a snapshot of information for the previous 24- hour period for optIfOCh interfaces contained in the ifTable.3.6.2.5. optIfOCh Sink Current Table
This table contains information on current performance of optIfOCh interfaces contained in the ifTable.3.6.2.6. optIfOCh Sink Interval Table
This table contains information on historic performance of optIfOCh interfaces contained in the ifTable.3.6.2.7. optIfOCh Sink Current Day Table
This table contains a snapshot of information for the current 24-hour period for optIfOCh interfaces contained in the ifTable.3.6.2.8. optIfOCh Sink Previous Day Table
This table contains a snapshot of information for the previous 24- hour period for optIfOCh interfaces contained in the ifTable.3.7. The optIfOTUk groups
3.7.1. optIfOTUk Configuration group
3.7.1.1. optIfOTUk Configuration Table
This table contains information on configuration of optIfOTUk interfaces, in addition to the information on such interfaces contained in the ifTable.3.7.2. optIfGCC0 Configuration group
3.7.2.1. optIfGCC0 Configuration Table
This table contains information on configuration of the GCC0 communication channel.
3.8. The optIfODUk groups
3.8.1. optIfODUk Configuration group
3.8.1.1. optIfODUk Configuration Table
This table contains all the objects that are common to endpoints (called trail termination points or TTPs) and connection termination points (CTPs), and also includes a flag stating whether TTP functions are present.3.8.2. optIfODUkTtp Configuration group
3.8.2.1. optIfODUkTtp Configuration Table
This table contains TTP-specific information on configuration of optIfODUk interfaces, in addition to the information on such interfaces contained in the ifTable.3.8.3. optIfODUk Position Seq group
3.8.3.1. optIfODUk Position Seq Table
This table contains information on the position sequence of the TCM function and/or GCC12 access that have been created within the optIfODUk interfaces, in addition to the information on such interfaces contained in the ifTable.3.8.4. optIfODUk Nim Configuration group
3.8.4.1. optIfODUk Nim Configuration Table
This table contains information on configuration of optIfODUk Non- intrusive monitoring.3.8.5. optIfGCC12 Configuration group
3.8.5.1. optIfGCC12 Configuration Table
This table contains information on configuration of the GCC1 and GCC2 communication channels.
3.9. The optIfODUkT groups
3.9.1. optIfODUkT Configuration group
3.9.1.1. optIfODUkT Configuration Table
This table contains information on configuration of optIfODUkT interfaces, in addition to the information on such interfaces contained in the ifTable.3.9.2. optIfODUkT Nim Configuration group
3.9.2.1. optIfODUkT Nim Configuration Table
This table contains information on configuration of optIfODUkT Non- intrusive monitoring.
(page 30 continued on part 2)
