| Internet-Draft | Opt. Impairment-Aware Topo YANG Model | November 2020 |
| Lee, et al. | Expires 6 May 2021 | [Page] |
In order to provision an optical connection through optical networks, a combination of path continuity, resource availability, and impairment constraints must be met to determine viable and optimal paths through the network. The determination of appropriate paths is known as Impairment-Aware Routing and Wavelength Assignment (IA-RWA) for WSON, while it is known as Impairment-Aware Routing and Spectrum Assigment (IA-RSA) for SSON.¶
This document provides a YANG data model for the impairment-aware TE topology in optical networks.¶
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In order to provision an optical connection (an optical path) through a wavelength switched optical networks (WSONs) or spectrum switched optical networks (SSONs), a combination of path continuity, resource availability, and impairment constraints must be met to determine viable and optimal paths through the network. The determination of appropriate paths is known as Impairment-Aware Routing and Wavelength Assignment (IA-RWA) [RFC6566] for WSON, while it is known as IA-Routing and Spectrum Assigment (IA-RSA) for SSON.¶
This document provides a YANG data model for the impairment-aware Traffic Engineering (TE) topology in WSONs and SSONs. The YANG model described in this document is a WSON/SSON technology-specific Yang model based on the information model developed in [RFC7446] and the two encoding documents [RFC7581] and [RFC7579] that developed protocol independent encodings based on [RFC7446].¶
The intent of this document is to provide a Yang data model, which can be utilized by a Multi-Domain Service Coordinator (MDSC) to collect states of WSON impairment data from the Transport PNCs to enable impairment-aware optical path computation according to the ACTN Architecture [RFC8453]. The communication between controllers is done via a NETCONF [RFC8341] or a RESTCONF [RFC8040]. Similarly,this model can also be exported by the MDSC to a Customer Network Controller (CNC), which can run an offline planning process to map latter the services in the network.¶
This document augments the generic TE topology draft [I-D.ietf-teas-yang-te-topo] where possible.¶
This document defines one YANG module: ietf-optical-impairment- topology (Section 3) according to the new Network Management Datastore Architecture [RFC8342].¶
Refer to [RFC6566], [RFC7698], and [G.807] for the key terms used in this document.¶
The following terms are defined in [RFC7950] and are not redefined here:¶
The following terms are defined in [RFC6241] and are not redefined here:¶
The terminology for describing YANG data models is found in [RFC7950].¶
A simplified graphical representation of the data model is used in Section 2 of this this document. The meaning of the symbols in these diagrams is defined in [RFC8340].¶
In this document, names of data nodes and other data model objects are prefixed using the standard prefix associated with the corresponding YANG imported modules, as shown in Table 1.¶
| Prefix | YANG module | Reference |
|---|---|---|
| optical-imp-topo | ietf-optical-impairment-topology | [RFCXXXX] |
| layer0-types | ietf-layer0-types | [I-D.ietf-ccamp-layer0-types] |
| nw | ietf-network | [RFC8345] |
| nt | ietf-network-topology | [RFC8345] |
| tet | ietf-te-topology | [I-D.ietf-teas-yang-te-topo] |
[Editor's note: The RFC Editor will replace XXXX with the number assigned to the RFC once this draft becomes an RFC.]¶
Figure 1 shows the control plane architecture.¶
+--------+
| MDSC |
+--------+
Scope of this ID -------> ||
| ||
| +------------------------+
| | OPTICAL |
+---------+ | | DOMAIN | +---------+
| Device | | | CONTROLLER | | Device |
| config. | | +------------------------+ | config. |
+---------+ v // || \\ +---------+
______|______ // || \\ ______|______
/ OT \ // || \\ / OT \
| +--------+ |// __--__ \\| +--------+ |
| |Vend. A |--|----+ ( ) +----|--| Vend. A| |
| +--------+ | | ~-( )-~ | | +--------+ |
| +--------+ | +---/ \---+ | +--------+ |
| |Vend. B |--|--+ / \ +--|--| Vend. B| |
| +--------+ | +---( OLS Segment )---+ | +--------+ |
| +--------+ | +---( )---+ | +--------+ |
| |Vend. C |--|--+ \ / +--|--| Vend. C| |
| +--------+ | +---\ /---+ | +--------+ |
| +--------+ | | ~-( )-~ | | +--------+ |
| |Vend. D |--|----+ (__ __) +----|--| Vend. D| |
| +--------+ | -- | +--------+ |
\_____________/ \_____________/
^ ^
| |
| |
Scope of [I-D.ietf-ccamp-dwdm-if-param-yang]
The models developed in this document is an abstracted Yang model that may be used in the interfaces between the MDSC and the Optical Domain Controller (aka MPI) and between the Optical Domain Controller and the Optical Device (aka SBI) in Figure 1. It is not intended to support a detailed low-level DWDM interface model. DWDM interface model is supported by the models presented in [I-D.ietf-ccamp-dwdm-if-param-yang].¶
This section provides the description of the reference optical network architecture and its relevant components to support optical impairment-aware path computation.¶
Figure 2 shows the reference architecture.¶
+-------------------+ +-------------------+
| ROADM Node | | ROADM Node |
| | | |
| PA +-------+ BA | ILA | PA +-------+ BA |
| +-+ | WSS/ | +-+ | _____ +--+ _____ | +-+ | WSS/ | +-+ |
--|-| |-|Filter |-| |-|-()____)-| |-()____)-|-| |-|Filter |-| |-|--
| +-+ | | +-+ | +--+ | +-+ | | +-+ |
| +-------+ | optical | +-------+ |
| | | | | fiber | | | | |
| o o o | | o o o |
| transponders | | transponders |
+-------------------+ +-------------------+
OTS Link OTS Link
<---------> <--------->
OMS Link
<-------------------------------->
PA: Pre-Amplifieror
BA: Booster Amplifier
ILA: In-Line Amplifier
BA (on the left side ROADM) is the ingress Amplifier and PA (on the right side ROADM is the egress amplifier for the OMS link shown in Figure 2.¶
According to [G.872], OMS Media Link represents a media link between two ROADMs. Specifically, it originates at the ROADM's Filter in the source ROADM and terminates at the ROADM's Filter in the destination ROADM.¶
OTS Media Link represents a media link: (i) between ROADM's BA and ILA; (ii) between a pair of ILAs; (iii) between ILA and ROADM's PA.¶
OMS Media link can be decomposed in a sequence of OTS links type (i), (ii), and (iii) as discussed above. OMS Media link would give an abstracted view of impairment data (e.g., power, OSNR, etc.) to the network controller.¶
For the sake of optical impairment evaluation OMS Media link can be also decomposed in a sequence of elements such as BA, fiber section, ILA, concentrated loss and PA.¶
[Editor's note: text below related to [G.807] needs to be revised! [G.807] is now in publication process.]¶
The OTSi is defined in ITU-T Recommendation G.959.1, section 3.2.4 [G.959.1]. The YANG model defined below assumes that a single OTSi consists of a single modulated optical carrier. This single modulated optical carrier conveys digital information. Characteristics of the OTSi signal are modulation scheme (e.g. QPSK, 8-QAM, 16-QAM, etc.), baud rate (measure of the symbol rate), pulse shaping (e.g. raised cosine - complying with the Nyquist inter symbol interference criterion), etc.¶
The definition of the OTSiG is currently being moved from ITU-T Recommendation G.709 [G.709] to the new draft Recommendation G.807 (still work in progress) [G.807]. The OTSiG is an electrical signal that is carried by one or more OTSi's. The relationship between the OTSiG and the the OTSi's is described in ITU-T draft Recommendation G.807, section 10.2 [G.807]. The YANG model below supports both cases: the single OTSi case where the OTSiG contains a single OTSi (see ITU-T draft Recommendation G.807, Figure 10-2) and the multiple OTSi case where the OTSiG consists of more than one OTSi (see ITU-T draft Recommendation G.807, Figure 10-3). From a layer 0 topology YANG model perspective, the OTSiG is a logical construct that associates the OTSi's, which belong to the same OTSiG. The typical application of an OTSiG consisting of more than one OTSi is inverse multiplexing. Constraints exist for the OTSi's belonging to the same OTSiG such as: (i) all OTSi's must be co-routed over the same optical fibers and nodes and (ii) the differential delay between the different OTSi's may not exceed a certain limit. Example: a 400Gbps client signal may be carried by 4 OTSi's where each OTSi carries 100Gbps of client traffic.¶
OTSiG
_________________________/\__________________________
/ \
m=7
- - - +---------------------------X---------------------------+ - - -
/ / / | | / / /
/ / /| OTSi OTSi OTSi OTSi |/ / /
/ / / | ^ ^ ^ ^ | / / /
/ / /| | | | | |/ / /
/ / / | | | | | | / / /
/ / /| | | | | |/ / /
-4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12
--+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---
n = 4
K1 K2 K3 K4
The definition of the MC is currently being moved from ITU-T Recommendation G.872 [G.872] to the new draft Recommendation G.807 (still work in progress) [G.807]. Section 3.2.2 defines the term MC and section 7.1.2 provides a more detailed description with some examples. The definition of the MC is very generic (see ITU-T draft Recommendation G.807, Figure 7-1). In the YANG model below, the MC is used with the following semantics:¶
The MC is an end-to-end topological network construct and can be considered as an "optical pipe" with a well-defined frequency slot between one or more optical transmitters each generating an OTSi and the corresponding optical receivers terminating the OTSi's. If the MC carries more than one OTSi, it is assumed that these OTSi's belong to the same OTSiG.¶
m=8
+-------------------------------X-------------------------------+
| | |
| +----------X----------+ | +----------X----------+ |
| | OTSi | | OTSi | |
| | ^ | | | ^ | |
| | | | | | | |
-4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12
--+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+-
| n=4 |
K1 K2
<------------------------ Media Channel ----------------------->
The frequency slot of the MC is defined by the n value defining the central frequency of the MC and the m value that defines the width of the MC following the flexible grid definition in ITU-T Recommendation G.694.1 [G.694.1]. In this model, the effective frequency slot as defined in ITU-T draft Recommendation G.807 is equal to the frequency slot of this end-to-end MC. It is also assumed that ROADM devices can switch MCs. For various reasons (e.g. differential delay), it is preferred to use a single MC for all OTSi's of the same OTSiG. It may however not always be possible to find a single MC for carrying all OTSi's of an OTSiG due to spectrum occupation along the OTSiG path.¶
The definition of the MCG is currently work in progress in ITU-T and is defined in section 7.1.3 of the new ITU-T draft Recommendation G.807 (still work in progress) [G.807]. The YANG model below assumes that the MCG is a logical grouping of one or more MCs that are used to to carry all OTSi's belonging to the same OTSiG.¶
The MCG can be considered as an association of MCs without defining a hierarchy where each MC is defined by its (n,m) value pair. An MCG consists of more than one MC when no single MC can be found from source to destination that is wide enough to accommodate all OTSi's (modulated carriers) that belong to the same OTSiG. In such a case the set of OTSi's belonging to a single OTSiG have to be split across 2 or more MCs.¶
MCG1 = {M1.1, M1.2}
__________________________/\________________________
/ \
M1.1 M2 M1.2
____________/\____________ _____/\_____ ____/\____
/ \/ \/ \
- - - +---------------------------+-------------+-----------+ - - -
/ / / | | / / / / / / | | / / /
/ / /| OTSi OTSi OTSi |/ / / / / / /| OTSi |/ / /
/ / / | ^ ^ ^ | / / / / / / | ^ | / / /
/ / /| | | | |/ / / / / / /| | |/ / /
/ / / | | | | | / / / / / / | | | / / /
/ / /| | | | |/ / / / / / /| | |/ / /
-7 -4 -1 0 1 2 3 4 5 6 7 8 ... 14 17 20
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
n=0 n=17
K1 K2 K3 K4
The MCG is relevant for path computation because all end-to-end MCs belonging to the same MCG have to be co-routed, i.e., have to follow the same path. Additional constraints may exist (e.g. differential delay).¶
Optical amplifiers are in charge of amplifying the optical signal in the optical itself without any electrical conversion. There are three main technologies to build amplifiers: Erbium Doped Fiber Amplifier (EDFA), Raman Fiber Amplifier (RFA), and Semiconductor Optical Amplifier (SOA). Nowadays, most of optical networks uses EDFAs. However, RFA has an attractive feature that it works in any wavelength band with a similar or lower noise figures compared to EDFA. On the other hand, RFAs consumes more power and are more expensive than EDFAs.¶
Amplifiers can be classified according to their location in the communication link. There are three basic types of amplifiers: ILA, Pre-Amplifier and Booster. ILA is In-Line Amplifier which is a separate node type while Pre-Amplifier and Booster Amplifier are integral elements of ROADM node. From a data modeling perspective, Pre-Amplifier and Booster Amplifier are internal functions of a ROADM node and as such these elements are hidden within ROADM node. In this document, we would avoid internal node details, but attempt to abstract as much as possible.¶
One modeling consideration of the ROADM internal is to model power parameter through the ROADM, factoring the output power from the Pre-Amplifier minus the ROADM power loss would give the input power to the Booster Amplifier. In other words, Power_in (@ ROADM Booster) = Power_out (@ ROADM Pre-Amplifier) - Power_loss (@ ROADM WSS/Filter).¶
[Editor's note: The relationship between the transponder and the OTSi in the YANG model described in Section 3 needs further clarification and refinement.]¶
A Transponder is the element that sends and receives the optical signal from a DWDM network. A transponder can comprise one or more transceivers. A transceiver can be seen as a pair of transmitter and receiver, as defined in ITU-T Recommendation G.698.2 [G.698.2].¶
A transponder is typically characterized by its data/symbol rate and the maximum distance the signal can travel. Other transponder properties are: carrier frequency for the optical channels, output power per channel, measured input power, modulation scheme, FEC, etc.¶
From a path computation perspective, the selection of the compatible configuration of the source and the destination transceivers is an important factor for optical signals to traverse through the DWDM network.¶
The YANG model defines three different approaches to describe the transceiver capabilities (called "modes") that are needed to determine optical signal compatibility:¶
An application code represents a standard ITU-T G.698.2 optical interface specification towards the realization of transversely compatible DWDM systems. Two transceivers supporting the same application code and a line system matching the constraints, defined in ITU-T G.698.2, for that application code will interoperate.¶
Organizations like operator groups, industry fora, or equipment vendors can define organizational modes, which will allow these organizations to make use of advanced transceiver capabilities going beyond existing standardized application codes. Such an organizational mode is identified by the organization-identifier attribute defining the scope and an operational-mode that is meaningful within the scope of the organization. Hence, the two attributes must always be considered together. Two transceivers are inter-operable, if they have at least one (organization-identifier, operational-mode) pair in common and if the supported carrier frequency and power attributes have a matching range. This is a necessary condition for path computation in the context of organizational modes. An operational mode is a transceiver preset (a configuration with well-defined parameter values) subsuming several transceiver properties including:¶
The major reason for these transceiver presets is the fact that the attribute values typically cannot be configured independently and are therefore advertised as supported operational mode capabilities. It is the responsibility of the organization to assign operational modes and to ensure that operational modes are unique and not ambiguous within the scope of the organization.¶
In addition to the transceiver properties subsumed by the operational mode, optical power and carrier frequency related properties are modeled separately, i.e., outside of the operational mode. This modeling approach allows transponders using different transceiver variants (e.g. optical modules) with slightly different power and/or frequency range properties to interoperate without defining separate operational modes. Different optical modules (pluggables) from different suppliers typically have slightly different input and output power ranges or may have slightly different carrier frequency tuning ranges.¶
The received channel power and the received total power are two parameters that can be measured by the receiver and can be provided by the transceiver in order to allow a controller to determine the expected performance of the end-to-end service taking into account the optical impairments along the path.¶
The explicit mode allows to encode, explicitly, any subset of parameters e.g., FEC type, Modulation type, etc, to enable a controller entity to check for interoperability by means outside of this draft. It shall be noted that using the explicit encoding does not guarantee interoperability between two transceivers even in case of identical parameter definitions. The explicit mode shall therefore be used with care, but it could be useful when no common Application Codes or Organizational Modes exist or the constraints of common Application Codes or Organizational Modes cannot be met by the line system.¶
The YANG model described in Section 3 defines the optical transceiver properties. They are divided between:¶
The transceiver capabilities are described by the set of modes the transceiver is supporting. Each mode MUST follow only one of the three mode options defined above (choice in the YANG model). The YANG model allows to describe the transceiver capabilities by mixing different modes. A transceiver may support some ITU-T application codes and in addition some organizational or explicit modes.¶
A transceiver mode description comprises the following properties:¶
These optical transceiver properties are explicitly defined in the model for explicit and organizational modes, while they are implicitly defined for the application codes (see ITU-T G698.2 [G.698.2]).¶
The set of optical impairment limits, e.g., min OSNR, max PMD, max CD, max PDL, Q-factor limit, are explicitly defined for the explicit modes while they are defined implicitly for the application codes and organizational modes.¶
It is possible that the set of parameter values defined for an explicit mode may also be represented in form of an organizational mode or one or more application codes. The "supported-mode" container may provide two different lists with pointers to application codes and organizational modes, respectively.¶
The current transponder configuration describes the properties of the OTSi transmitted or received by the transceiver attached to a specific transponder port.¶
Each OTSi has the following three pointer attributes modeled as leafrefs:¶
Additionally, the OTSi is described by the following frequency and optical power related attributes:¶
WSS separates the incoming light input spectrally as well as spatially, then chooses the wavelength that is of interest by deflecting it from the original optical path and then couple it to another optical fibre port. WSS/Filter is internal to ROADM. So this document does not model the inside of ROADM.¶
There are various optical fiber types defined by ITU-T. There are several fiber-level parameters that need to be factored in, such as, fiber-type, length, loss coefficient, pmd, connectors (in/out).¶
ITU-T G.652 defines Standard Singlemode Fiber; G.654 Cutoff Shifted Fiber; G.655 Non-Zero Dispersion Shifted Fiber; G.656 Non-Zero Dispersion for Wideband Optical Transport; G.657 Bend-Insensitive Fiber. There may be other fiber-types that need to be considered.¶
The ROADM node architectures in today's dense wavelength division multiplexing (DWDM) networks can be categorized as follows:¶
The TE topology YANG model augmentations including optical impairments for DWDM networks defined below intend to cover all the 3 categories of ROADM architectures listed above. In the case of a disaggregated ROADM architecture, it is assumed that optical domain controller already performs some form of abstraction and presents the TE-node representing the disaggregated ROADM in the same way as an integrated ROADM with integrated optical transponders if the optical transponder subsystems and the add/drop subsystems are collocated (short fiber links not imposing significant optical impairments).¶
The different ROADM architectures are briefly described and illustrated in the following subsections.¶
[Editor's note: The modeling of remote optical transponders located for example in the client device with a single channel link between the OT and the add/drop port of the ROADM requires further investigations and will be addressed in a future revision of this document.]¶
Figure 2 and Figure 6 below show the typical architecture of an integrated ROADM node, which contains the optical transponders as an integral part of the ROADM node. Such an integrated ROADM node provides DWDM interfaces as external interfaces for interconnecting the device with its neighboring ROADMs (see OTS link above). The number of these interfaces denote also the degree of the ROADM. A degree 3 ROADM for example has 3 DWDM links that interconnect the ROADM node with 3 neighboring ROADMs. Additionally, the ROADM provides client interfaces for interconnecting the ROADM with client devices such as IP routers or Ethernet switches. These client interfaces are the client interfaces of the integrated optical transponders.¶
. . . . . . . . . . . . . . . . . .
+-----.-------------------------------- .-----+
| . ROADM . |
| . /| +-----------------+ |\ . |
Line | . / |--| |--| \ . | Line
WEST | /| . | |--| |--| | . |\ | EAST
------+-/ |-.-| |--| OCX |--| |-.-| \-+-----
------+-\ |-.-| |--| |--| |-.-| /-+-----
| \| . | |--| |--| | . |/ |
| . \ |--| |--| / . |
| . \| +-----------------+ |/ . |
| . . |
| . +---+ +---+ +---+ +---+ . |
| . | O | | O | | O | | O | . |
| . | T | | T | | T | | T | . |
| . +---+ +---+ +---+ +---+ . |
| . | | | | | | | | . |
+-----.------+-+---+-+---+-+---+-+------.-----+
. . . .|.| . |.| . |.| . |.|. . . .
| | | | | | | | TE Node
Client Interfaces
Figure 7 below shows the extreme case where all optical transponders are not integral parts of the ROADM but are separate devices that are interconnected with add/drop ports of the ROADM. If the optical transponders and the ROADM are collocated and if short single channel fiber links are used to interconnect the optical transponders with an add/drop port of the ROADM, the optical domain controller may present these optical transponders in the same way as integrated optical transponders. If, however, the optical impairments of the single channel fiber link between the optical transponder and the add/drop port of the ROADM cannot be neglected, it is necessary to represent the fiber link with its optical impairments in the topology model This also implies that the optical transponders belong to a separate TE node¶
[Editor's note: this requires further study].¶
. . . . . . . . . . . . . . . . . .
. Abstracted ROADM .
+-----.-------------------------------- .-----+
| . ROADM . |
| . /| +-----------------+ |\ . |
Line | . / |--| |--| \ . | Line
WEST | /| . | |--| |--| | . |\ | EAST
------+-/ |-.-| |--| OCX |--| |-.-| \-+-----
------+-\ |-.-| |--| |--| |-.-| /-+-----
| \| . | |--| |--| | . |/ |
| . \ |--| |--| / . |
| . \| +-----------------+ |/ . |
+-----.---------|----|---|----|---------.-----|
Colored OT . +-+ ++ ++ +-+ .
line I/F . | | | | .
. +---+ +---+ +---+ +---+ .
. | O | | O | | O | | O | .
. | T | | T | | T | | T | .
. +---+ +---+ +---+ +---+ .
. . . .|.| . |.| . |.| . |.|. . . .
| | | | | | | | TE Node
Client Interfaces
Recently, some DWDM network operators started demanding ROADM subsystems from their vendors. An example is the OpenROADM project where multiple operators and vendors are developing related YANG models. The subsystems of a disaggregated ROADM are: single degree subsystems, add/drop subsystems and optical transponder subsystems. These subsystems separate network elements and each network element provides a separate management and control interface. The subsystems are typically interconnected using short fiber patch cables and form together a disaggregated ROADM node. This disaggregated ROADM architecture is depicted in Figure 8 below.¶
As this document defines TE topology YANG model augmentations [I-D.ietf-teas-yang-te-topo] for the TE topology YANG model provided at the north-bound interface of the optical domain controller, it is a valid assumption that the optical domain controller abstracts the subsystems of a disaggregated ROADM and presents the disaggregated ROADM in the same way as an integrated ROADM hiding all the interconnects that are not relevant from an external TE topology view.¶
. . . . . . . . . . . . . . . . . .
. Abstracted ROADM .
+-----.----------+ +----------.-----+
| Degree 1 | | Degree 2 |
Line | . +-----+ | + +-----+ . | Line
1 | /| . | W |-|------------|-| W | . |\ | 2
-----+-/ |-.--| S ******** ******** S |--.-| \-+-----
-----+-\ |-.--| S | | * * | | S |--.-| /-+-----
| \| . | |-|-+ * * +-|-| | . |/ |
| . +-+-+-+ | | * * | | +-+-+-+ . |
+-----.----|-----+ | * * | +-----|----.-----+
. | | * * | | .
+-----.----|-----+ | * * | +-----|----.-----+
| Degree 4 | | | * * | | | Degree 3 |
Line | . +-----+ | | * * | | +-----+ . | Line
4 | /| . | W |-|-|--*--*--+ | | W | . |\ | 3
-----+-/ |-.--| S | | +--*--*----|-| S |--.-| \-+-----
-----+-\ |-.--| S |-|----*--*----|-| S |--.-| /-+-----
| \| . | | | * * | | | . |/ |
| . +--*--+ | * * | +--*--+ . |
+-----.-----*----+ * * +----*-----.-----+
. * * * * .
. +--*---------*--*---------*--+ .
. | ADD | .
. | DROP | .
. +----------------------------+ .
Colored OT . | | | | .
Line I/F . +---+ +---+ +---+ +---+ .
. | O | | O | | O | | O | .
. | T | | T | | T | | T | .
. +---+ +---+ +---+ +---+ .
. . .|.| . |.| . |.| . |.|. . .
| | | | | | | | TE Node
Client Interfaces
When an optical OTSi signal traverses a ROADM node, optical impairments are imposed on the signal by various passive or active optical components inside the ROADM node. Examples of optical impairments are:¶
A ROADM node contains a wavelength selective photonic switching function (WSS)that is capable of switching media channels (MCs) described in Section 2.3.4. These MCs can be established between two line ports of the ROADM or between a line port and an Add/Drop port of the ROADM. The Add/Drop ports of a ROADM are those ports to which optical transponders are connected. Typically, this is a single channel signal (single OTSi), but principally this could also be a group of OTSi signals. The optical impairments associated with these MCs are different and the paths of the MCs inside the ROADM node can be categorized as follows:¶
Due to the symmetrical architecture of the ROADM node, the optical impairments associated with the express path are typically the same between any two line ports of the ROADM whereas the optical impairments for the add and drop paths are different and therefore have to be modeled separately.¶
The optical impairments associated with each of the three types of ROADM-node-internal paths described above are modeled as optical impairment parameter sets. These parameter sets are modeled as an augmentation of the te-node-attributes defined in [I-D.ietf-teas-yang-te-topo]. The te-node-attributes are augmented with a list of roadm-path-impairments for the three ROADM path types distinguished by the impairment-type. Each roadm-path-impairments list entry contains the set of optical impairment parameters for one of the three path types indicated by the impairment-type. For the optical feasibility calculation based on the optical impairments, it is necessary to know whether the optical power of the OTSi stays within a certain power window. This is reflected by some optical power related parameters such as loss parameters or power parameters, which are included in the optical impairment parameter sets (see tree view in Section 3).¶
[I-D.ietf-teas-yang-te-topo] defines a connectivity matrix and a local link connectivity list for the TE node. The connectivity matrix describes the connectivity for the express paths between the different lines of the ROADM and the local link connectivity list describes the connectivity for the Add and Drop paths of the ROADM. These matrices are augmented with a new roadm-path-impairment matrix element, an add-path-impairment, and drop-path-impairment matrix element, respectively, which are defined as a pointer to the corresponding entry in the roadm-path-impairments list (leaf-ref).¶
[Editor's note: this section is still work in progress]¶
module: ietf-optical-impairment-topology
augment /nw:networks/nw:network/nw:network-types/tet:te-topology:
+--rw optical-impairment-topology!
augment /nw:networks/nw:network/nt:link/tet:te
/tet:te-link-attributes:
+--ro OMS-attributes
+--ro generalized-snr? l0-types-ext:snr
+--ro equalization-mode identityref
+--ro (power-param)?
| +--:(channel-power)
| | +--ro nominal-channel-power? decimal64
| +--:(power-spectral-density)
| +--ro nominal-power-spectral-density? decimal64
+--ro media-channel-group* [i]
| +--ro i int16
| +--ro media-channels* [flexi-n]
| +--ro flexi-n l0-types:flexi-n
| +--ro flexi-m? l0-types:flexi-m
| +--ro OTSiG-ref? leafref
| +--ro OTSi-ref? leafref
+--ro OMS-elements* [elt-index]
+--ro elt-index uint16
+--ro uid? string
+--ro type identityref
+--ro element
+--ro (element)?
+--:(amplifier)
| +--ro amplifier
| +--ro type-variety string
| +--ro operational
| +--ro actual-gain
| | decimal64
| +--ro tilt-target
| | decimal64
| +--ro out-voa
| | decimal64
| +--ro in-voa
| | decimal64
| +--ro (power-param)?
| +--:(channel-power)
| | +--ro nominal-channel-power?
| | decimal64
| +--:(power-spectral-density)
| +--ro nominal-power-spectral-density?
| decimal64
+--:(fiber)
| +--ro fiber
| +--ro type-variety string
| +--ro length decimal64
| +--ro loss-coef decimal64
| +--ro total-loss decimal64
| +--ro pmd? decimal64
| +--ro conn-in? decimal64
| +--ro conn-out? decimal64
+--:(concentratedloss)
+--ro concentratedloss
+--ro loss? decimal64
augment /nw:networks/nw:network/nw:node/tet:te
/tet:tunnel-termination-point:
+--ro otsi-group* [otsi-group-id]
| +--ro otsi-group-id int16
| +--ro otsi* [otsi-carrier-id]
| +--ro otsi-carrier-id int16
| +--ro transponder-ref? leafref
| +--ro transceiver-ref? leafref
| +--ro configured-mode? leafref
| +--ro OTSi-carrier-frequency? frequency-thz
| +--ro tx-channel-power? dbm-t
| +--ro rx-channel-power? dbm-t
| +--ro rx-total-power? dbm-t
+--ro transponder* [transponder-id]
+--ro transponder-id uint32
+--ro transceiver* [transceiver-id]
+--ro transceiver-id uint32
+--ro supported-modes
+--ro supported-mode* [mode-id]
+--ro mode-id string
+--ro (mode)
+--:(G.698.2)
| +--ro standard-mode? standard-mode
+--:(organizational-mode)
| +--ro organizational-mode
| +--ro operational-mode?
| | operational-mode
| +--ro organization-identifier?
| | organization-identifier
| +--ro min-central-frequency?
| | frequency-thz
| +--ro max-central-frequency?
| | frequency-thz
| +--ro minimum-channel-spacing?
| | frequency-ghz
| +--ro tx-channel-power-min? dbm-t
| +--ro tx-channel-power-max? dbm-t
| +--ro rx-channel-power-min? dbm-t
| +--ro rx-channel-power-max? dbm-t
| +--ro rx-total-power-max? dbm-t
+--:(explicit-mode)
+--ro explicit-mode
+--ro supported-modes
| +--ro supported-application-codes*
| | -> ../../mode-id
| +--ro supported-organizational-modes*
| -> ../../mode-id
+--ro line-coding-bitrate?
| identityref
+--ro max-polarization-mode-dispersion?
| decimal64
+--ro max-chromatic-dispersion?
| decimal64
+--ro chromatic-and-polarization-dispersion-penalty* []
| +--ro chromatic-dispersion
| | decimal64
| +--ro polarization-mode-dispersion
| | decimal64
| +--ro penalty
| decimal64
+--ro max-diff-group-delay?
| int32
+--ro max-polarization-dependent-loss?
| decimal64
+--ro available-modulation-type?
| identityref
+--ro OTSi-carrier-bandwidth?
| frequency-ghz
+--ro min-OSNR?
| snr
+--ro min-Q-factor?
| int32
+--ro available-baud-rate?
| uint32
+--ro available-FEC-type?
| identityref
+--ro FEC-code-rate?
| decimal64
+--ro FEC-threshold?
| decimal64
+--ro min-central-frequency?
| frequency-thz
+--ro max-central-frequency?
| frequency-thz
+--ro minimum-channel-spacing?
| frequency-ghz
+--ro tx-channel-power-min?
| dbm-t
+--ro tx-channel-power-max?
| dbm-t
+--ro rx-channel-power-min?
| dbm-t
+--ro rx-channel-power-max?
| dbm-t
+--ro rx-total-power-max?
dbm-t
augment /nw:networks/nw:network/nw:node/tet:te
/tet:tunnel-termination-point:
+--ro sliceable-transponder-list* [carrier-id]
+--ro carrier-id uint32
augment /nw:networks/nw:network/nw:node/tet:te
/tet:te-node-attributes:
+--ro roadm-path-impairments* [roadm-path-impairments-id]
+--ro roadm-path-impairments-id uint32
+--ro (impairment-type)?
+--:(roadm-express-path)
| +--ro roadm-express-path
| +--ro roadm-pmd? decimal64
| +--ro roadm-cd? decimal64
| +--ro roadm-pdl? decimal64
| +--ro roadm-inband-crosstalk? decimal64
| +--ro roadm-maxloss? decimal64
+--:(roadm-add-path)
| +--ro roadm-add-path
| +--ro roadm-pmd? decimal64
| +--ro roadm-cd? decimal64
| +--ro roadm-pdl? decimal64
| +--ro roadm-inband-crosstalk? decimal64
| +--ro roadm-maxloss? decimal64
| +--ro roadm-pmax? decimal64
| +--ro roadm-osnr? l0-types-ext:snr
| +--ro roadm-noise-figure? decimal64
+--:(roadm-drop-path)
+--ro roadm-drop-path
+--ro roadm-pmd? decimal64
+--ro roadm-cd? decimal64
+--ro roadm-pdl? decimal64
+--ro roadm-inband-crosstalk? decimal64
+--ro roadm-maxloss? decimal64
+--ro roadm-minloss? decimal64
+--ro roadm-typloss? decimal64
+--ro roadm-pmin? decimal64
+--ro roadm-pmax? decimal64
+--ro roadm-ptyp? decimal64
+--ro roadm-osnr? l0-types-ext:snr
+--ro roadm-noise-figure? decimal64
augment /nw:networks/nw:network/nw:node/tet:te
/tet:information-source-entry/tet:connectivity-matrices:
+--ro roadm-path-impairments? leafref
augment /nw:networks/nw:network/nw:node/tet:te
/tet:information-source-entry/tet:connectivity-matrices
/tet:connectivity-matrix:
+--ro roadm-path-impairments? leafref
augment /nw:networks/nw:network/nw:node/tet:te
/tet:te-node-attributes/tet:connectivity-matrices:
+--ro roadm-path-impairments?
-> ../../roadm-path-impairments/roadm-path-impairments-id
augment /nw:networks/nw:network/nw:node/tet:te
/tet:te-node-attributes/tet:connectivity-matrices
/tet:connectivity-matrix:
+--ro roadm-path-impairments? leafref
augment /nw:networks/nw:network/nw:node/tet:te
/tet:tunnel-termination-point
/tet:local-link-connectivities:
+--ro add-path-impairments? leafref
+--ro drop-path-impairments? leafref
augment /nw:networks/nw:network/nw:node/tet:te
/tet:tunnel-termination-point
/tet:local-link-connectivities
/tet:local-link-connectivity:
+--ro add-path-impairments? leafref
+--ro drop-path-impairments? leafref
¶
[Editor's note: YANG code below may have to be updated before submission!]¶
<CODE BEGINS>
module ietf-optical-impairment-topology {
yang-version 1.1;
namespace "urn:ietf:params:xml"
+":ns:yang:ietf-optical-impairment-topology";
prefix "optical-imp-topo";
import ietf-network {
prefix "nw";
}
import ietf-network-topology {
prefix "nt";
}
import ietf-te-topology {
prefix "tet";
}
import ietf-layer0-types {
prefix "l0-types";
}
import ietf-layer0-types-ext {
prefix "l0-types-ext";
}
organization
"IETF CCAMP Working Group";
contact
"Editor: Young Lee <younglee.tx@gmail.com>
Editor: Haomian Zheng <zhenghaomian@huawei.com>
Editor: Nicola Sambo <nicosambo@gmail.com>
Editor: Victor Lopez <victor.lopezalvarez@telefonica.com>
Editor: Gabriele Galimberti <ggalimbe@cisco.com>
Editor: Giovanni Martinelli <giomarti@cisco.com>
Editor: Jean-Luc Auge <jeanluc.auge@orange.com>
Editor: Le Rouzic Esther <esther.lerouzic@orange.com>
Editor: Julien Meuric <julien.meuric@orange.com>
Editor: Italo Busi <Italo.Busi@huawei.com>
Editor: Dieter Beller <dieter.beller@nokia.com>
Editor: Sergio Belotti <Sergio.belotti@nokia.com>
Editor: Griseri Enrico <enrico.griseri@nokia.com>
Editor: Gert Grammel <ggrammel@juniper.net>";
description
"This module contains a collection of YANG definitions for
impairment-aware optical networks.
Copyright (c) 2019 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD
License set forth in Section 4.c of the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove
// this note
// replace the revision date with the module publication date
// the format is (year-month-day)
revision 2020-10-13 {
description
"Initial Version";
reference
"RFC XXXX: A Yang Data Model for Impairment-aware
Optical Networks";
}
// identity
identity modulation {
description "base identity for modulation type";
}
identity QPSK {
base modulation;
description
"QPSK (Quadrature Phase Shift Keying) modulation";
}
identity DP-QPSK {
base modulation;
description
"DP-QPSK (Dual Polarization Quadrature
Phase Shift Keying) modulation";
}
identity QAM8 {
base modulation;
description
"8QAM (8-State Quadrature Amplitude Modulation) modulation";
}
identity QAM16 {
base modulation;
description
"QAM16 (Quadrature Amplitude Modulation)";
}
identity DP-QAM8 {
base modulation;
description
"DP-QAM8 (Dual Polarization Quadrature Amplitude Modulation)";
}
identity DC-DP-QAM8 {
base modulation;
description
"DC DP-QAM8 (Dual Polarization Quadrature Amplitude Modulation)";
}
identity DP-QAM16 {
base modulation;
description
"DP-QAM16 (Dual Polarization Quadrature Amplitude Modulation)";
}
identity DC-DP-QAM16 {
base modulation;
description
"DC DP-QAM16 (Dual Polarization Quadrature
Amplitude Modulation)";
}
identity FEC {
description
"Enumeration that defines the type of
Forward Error Correction";
}
identity reed-solomon {
base FEC;
description
"Reed-Solomon error correction";
}
identity hamming-code {
base FEC;
description
"Hamming Code error correction";
}
identity golay {
base FEC;
description "Golay error correction";
}
// typedef
typedef fiber-type {
type enumeration {
enum G.652 {
description "G.652 Standard Singlemode Fiber";
}
enum G.654 {
description "G.654 Cutoff Shifted Fiber";
}
enum G.653 {
description "G.653 Dispersion Shifted Fiber";
}
enum G.655 {
description "G.655 Non-Zero Dispersion Shifted Fiber";
}
enum G.656 {
description "G.656 Non-Zero Dispersion for Wideband
Optical Transport";
}
enum G.657 {
description "G.657 Bend-Insensitive Fiber";
}
}
description
"ITU-T based fiber-types";
}
// grouping
grouping transponder-attributes {
description "Configuration of an optical transponder";
leaf-list available-modulation-types {
type identityref {
base modulation;
}
config false;
description
"List of modulation types the OTSi supports";
}
leaf configured-modulation-type {
type identityref {
base modulation;
}
config false;
description
"Currently configured OTSi modulation type";
}
leaf-list available-baud-rates {
type uint32;
units Bd;
config false;
description
"list of available baud-rates.
Baud-rate is the unit for
symbol rate or modulation rate
in symbols per second or
pulses per second.
It is the number of distinct symbol
changes (signal events) made to the
transmission medium
per second in a digitally
modulated signal or a line code";
}
leaf configured-baud-rate {
type uint32;
units Bd;
config false;
description "configured baud-rate";
}
leaf-list available-FEC-types {
type identityref {
base FEC;
}
config false;
description "List determining all the available FEC";
}
leaf configured-FEC-type {
type identityref {
base FEC;
}
config false;
description
"FEC type configured for the transponder";
}
leaf FEC-code-rate {
type decimal64 {
fraction-digits 8;
range "0..max";
}
config false;
description "FEC-code-rate";
}
leaf FEC-threshold {
type decimal64 {
fraction-digits 8;
range "0..max";
}
config false;
description
"Threshold on the BER, for which FEC
is able to correct errors";
}
}
grouping sliceable-transponder-attributes {
description
"Configuration of a sliceable transponder.";
list sliceable-transponder-list {
key "carrier-id";
config false;
description "List of carriers";
leaf carrier-id {
type uint32;
config false;
description "Identifier of the carrier";
}
}
}
grouping optical-fiber-data {
description
"optical link (fiber) attributes with impairment data";
leaf fiber-type {
type fiber-type;
config false;
description "fiber-type";
}
leaf span-length {
type decimal64 {
fraction-digits 2;
}
units "km";
config false;
description "the lenght of the fiber span in km";
}
leaf input-power {
type decimal64 {
fraction-digits 2;
}
units "dBm";
config false;
description
"Average input power level estimated at the receiver
of the link";
}
leaf output-power {
type decimal64 {
fraction-digits 2;
}
units "dBm";
description
"Mean launched power at the transmitter of the link";
}
leaf pmd {
type decimal64 {
fraction-digits 8;
range "0..max";
}
units "ps/(km)^0.5";
config false;
description
"Polarization Mode Dispersion";
}
leaf cd {
type decimal64 {
fraction-digits 5;
}
units "ps/nm/km";
config false;
description
"Cromatic Dispersion";
}
leaf osnr {
type l0-types-ext:snr;
config false;
description
"Optical Signal-to-Noise Ratio (OSNR) estimated
at the receiver";
}
leaf sigma {
type decimal64 {
fraction-digits 5;
}
units "dB";
config false;
description
"sigma in the Gausian Noise Model";
}
}
grouping optical-channel-data {
description
"optical impairment data per channel/wavelength";
leaf bit-rate {
type decimal64 {
fraction-digits 8;
range "0..max";
}
units "Gbit/s";
config false;
description
"Gross bit rate";
}
leaf BER {
type decimal64 {
fraction-digits 18;
range "0..max";
}
config false;
description
"BER (Bit Error Rate)";
}
leaf ch-input-power {
type decimal64 {
fraction-digits 2;
}
units "dBm";
config false;
description
"Per channel average input power level
estimated at the receiver of the link";
}
leaf ch-pmd {
type decimal64 {
fraction-digits 8;
range "0..max";
}
units "ps/(km)^0.5";
config false;
description
"per channel Polarization Mode Dispersion";
}
leaf ch-cd {
type decimal64 {
fraction-digits 5;
}
units "ps/nm/km";
config false;
description
"per channel Cromatic Dispersion";
}
leaf ch-osnr {
type l0-types-ext:snr;
config false;
description
"per channel Optical Signal-to-Noise Ratio
(OSNR) estimated at the receiver";
}
leaf q-factor {
type decimal64 {
fraction-digits 5;
}
units "dB";
config false;
description
"q-factor estimated at the receiver";
}
}
/*
* Identities
*/
identity type-element {
description
"Base identity for element type";
}
identity Fiber {
base type-element;
description
"Fiber element";
}
identity Roadm {
base type-element;
description
"Roadm element";
}
identity Edfa {
base type-element;
description
"Edfa element";
}
identity Concentratedloss {
base type-element;
description
"Concentratedloss element";
}
identity type-power-mode {
description
"power equalization mode used within the
OMS and its elements";
}
identity power-spectral-density {
base type-power-mode;
description
"all elements must use power spectral density (W/Hz)";
}
identity channel-power {
base type-power-mode;
description
"all elements must use power (dBm)";
}
/*
* Groupings
*/
grouping amplifier-params {
description "describes parameters for an amplifier";
container amplifier{
description "amplifier type, operatonal parameters
are described";
leaf type-variety {
type string ;
mandatory true ;
description
"String identifier of amplifier type referencing
a specification in a separate equipment catalog";
}
container operational {
description "amplifier operationnal parameters";
leaf actual-gain {
type decimal64 {
fraction-digits 2;
}
units dB ;
mandatory true ;
description "..";
}
leaf tilt-target {
type decimal64 {
fraction-digits 2;
}
mandatory true ;
description "..";
}
leaf out-voa {
type decimal64 {
fraction-digits 2;
}
units dB;
mandatory true;
description "..";
}
leaf in-voa {
type decimal64 {
fraction-digits 2;
}
units dB;
mandatory true;
description "..";
}
uses power-param;
}
}
}
grouping fiber-params {
description
"String identifier of fiber type referencing a
specification in a separate equipment catalog";
container fiber {
description "fiber characteristics";
leaf type-variety {
type string ;
mandatory true ;
description "fiber type";
}
leaf length {
type decimal64 {
fraction-digits 2;
}
units km;
mandatory true ;
description "length of fiber";
}
leaf loss-coef {
type decimal64 {
fraction-digits 2;
}
units dB/km;
mandatory true ;
description "loss coefficient of the fiber";
}
leaf total-loss {
type decimal64 {
fraction-digits 2;
}
units dB;
mandatory true ;
description
"includes all losses: fiber loss and conn-in and
conn-out losses";
}
leaf pmd{
type decimal64 {
fraction-digits 2;
}
units sqrt(ps);
description "pmd of the fiber";
}
leaf conn-in{
type decimal64 {
fraction-digits 2;
}
units dB;
description "connector-in";
}
leaf conn-out{
type decimal64 {
fraction-digits 2;
}
units dB;
description "connector-out";
}
}
}
grouping roadm-express-path {
description "roadm express path optical impairments";
container roadm-express-path {
description "roadm parameters per express path";
leaf roadm-pmd {
type decimal64 {
fraction-digits 8;
range "0..max";
}
units "ps/(km)^0.5";
description
"Polarization Mode Dispersion";
}
leaf roadm-cd {
type decimal64 {
fraction-digits 5;
}
units "ps/nm";
description "Chromatic Dispersion";
}
leaf roadm-pdl {
type decimal64 {
fraction-digits 2;
}
units dB ;
description "Polarization dependent loss";
}
leaf roadm-inband-crosstalk {
type decimal64 {
fraction-digits 2;
}
units dB;
description
"In-band crosstalk, or coherent crosstalk, can occur in
components that can have multiple same wavelength inputs
with the inputs either routed to different output ports,
or all but 1 blocked";
}
leaf roadm-maxloss {
type decimal64 {
fraction-digits 2;
}
units dB;
description
"This is the maximum expected add path loss from the
ROADM ingress to the ROADM egress
assuming no additional add path loss is added";
}
}
}
grouping roadm-add-path {
description "roadm add block path optical impairments";
container roadm-add-path {
description "roadm optical impairment parameters
per add path";
leaf roadm-pmd {
type decimal64 {
fraction-digits 8;
range "0..max";
}
units "ps";
description
"Polarization Mode Dispersion";
}
leaf roadm-cd {
type decimal64 {
fraction-digits 5;
}
units "ps/nm";
description "Cromatic Dispersion";
}
leaf roadm-pdl {
type decimal64 {
fraction-digits 2;
}
units dB ;
description "Polarization dependent loss";
}
leaf roadm-inband-crosstalk {
type decimal64 {
fraction-digits 2;
}
units dB ;
description
"In-band crosstalk, or coherent crosstalk,
can occur in components that can have multiple same
wavelength inputs,with the inputs either
routed to different output ports,
or all but 1 blocked.
In the case of add path it is the total
of the add block
+ egress WSS crosstalk contributions.";
}
leaf roadm-maxloss {
type decimal64 {
fraction-digits 2;
}
units dB ;
description
"This is the maximum expected add path loss from
the add/drop port input to the ROADM egress,
assuming no additional add path loss is added.
This is used to establish the minimum required
transponder output power required
to hit the ROADM egress target power
levels and preventing
to hit the WSS attenuation limits.
If the add path contains an internal amplifier
this loss value should be based
on worst case expected amplifier gain due to
ripple or gain uncertainty";
}
leaf roadm-pmax {
type decimal64 {
fraction-digits 2;
}
units dBm ;
description
"This is the maximum (per carrier) power level
permitted at the add block input ports,
that can be handled by the ROADM node.
This may reflect either add amplifier power
contraints or WSS adjustment limits.
Higher power transponders would need to have
their launch power reduced
to this value or lower";
}
leaf roadm-osnr {
type l0-types-ext:snr;
description
"Optical Signal-to-Noise Ratio (OSNR).
If the add path contains the ability to adjust the
carrier power levels into an add path amplifier
(if present) to a target value,
this reflects the OSNR contribution of the
add amplifier assuming this target value is obtained.
The worst case OSNR based on the input power and
NF calculation method, and this value, should be used
(if both are defined).";
}
leaf roadm-noise-figure {
type decimal64 {
fraction-digits 5;
}
units "dB";
description
"Noise Figure. If the add path contains an amplifier,
this is the noise figure of that amplifier inferred
to the add port.
This permits add path OSNR calculation based
on the input power levels to the add block
without knowing the ROADM path losses to
the add amplifier.";
}
}
}
grouping roadm-drop-path {
description "roadm drop block path optical impairments";
container roadm-drop-path {
description "roadm optical impairment parameters
per drop path";
leaf roadm-pmd {
type decimal64 {
fraction-digits 8;
range "0..max";
}
units "ps/(km)^0.5";
description
"Polarization Mode Dispersion";
}
leaf roadm-cd {
type decimal64 {
fraction-digits 5;
}
units "ps/nm";
description "Chromatic Dispersion";
}
leaf roadm-pdl {
type decimal64 {
fraction-digits 2;
}
units dB ;
description "Polarization dependent loss";
}
leaf roadm-inband-crosstalk {
type decimal64 {
fraction-digits 2;
}
units dB;
description
"In-band crosstalk, or coherent crosstalk, can occur in
components that can have multiple same wavelength
inputs,with the inputs either routed to different
output ports,or all but 1 blocked.
In the case of drop path it is the total
of the ingress
to drop e.g. WSS and drop block crosstalk
contributions.";
}
leaf roadm-maxloss {
type decimal64 {
fraction-digits 2;
}
units dB ;
description
"The net loss from the ROADM input,to the output
of the drop block.
If ROADM ingress to drop path includes an amplifier,
the amplifier gain reduces the net loss.
This is before any additional drop path attenuation
that may be required
due to drop amplifier power contraints.
The max value correspond to worst case expected loss,
including amplifier gain ripple or uncertainty.
It is the maximum output power of the drop
amplifier.";
}
leaf roadm-minloss {
type decimal64 {
fraction-digits 2;
}
units dB ;
description
"The net loss from the ROADM input, to the
output of the drop block.
If this ROADM ingress to drop path includes
an amplifier,the amplifier gain reduces the net loss.
This is before any additional drop path attenuation
that may be required due to drop amplifier power
contraints.
The min value correspond to best case expected loss,
including amplifier gain ripple or uncertainty.";
}
leaf roadm-typloss {
type decimal64 {
fraction-digits 2;
}
units dB ;
description
"The net loss from the ROADM input,
to the output of the drop block.
If this ROADM ingress to drop path
includes an amplifier,
the amplifier gain reduces the net loss.
This is before any additional drop path
attenuation
that may be required due to drop amplifier
power contraints.
The typ value correspond to typical case
expected loss.";
}
leaf roadm-pmin {
type decimal64 {
fraction-digits 2;
}
units dBm ;
description
"If the drop path has additional loss
that is added, for example,
to hit target power levels into a
drop path amplifier, or simply, to reduce the
power of a “strong” carrier
(due to ripple,for example),
then the use of the ROADM input power levels and
the above drop losses is not appropriate.
This parameter corresponds to the min per
carrier power levels
expected at the output of the drop block.
A detail example of the comparison using
these parameters is
detailed in section xxx of the document yyy.";
}
leaf roadm-pmax {
type decimal64 {
fraction-digits 2;
}
units dBm ;
description
"If the drop path has additional loss that is added,
for example, to hit target power levels into a
drop path amplifier,or simply,to reduce the power
of a “strong” carrier(due to ripple,for example),
then the use of the ROADM input power levels and the
above drop losses is not appropriate.
This parameter corresponds to the best case per
carrier power levels expected at the output of the
drop block.
A detail example of the comparison using
these parameters
is detailed in section xxx of the document yyy";
}
leaf roadm-ptyp {
type decimal64 {
fraction-digits 2;
}
units dBm ;
description
"If the drop path has additional loss that is added,
for example, to hit target power levels into a
drop path amplifier,or simply,to reduce the
power of a “strong” carrier(due to ripple,for example),
then the use of the ROADM input power levels and
the above drop losses is not appropriate.
This parameter corresponds to the typical case
per carrier power levels expected
at the output of the drop block.";
}
leaf roadm-osnr {
type l0-types-ext:snr;
description
"Optical Signal-to-Noise Ratio (OSNR).
Expected OSNR contribution of the drop path
amplifier(if present)
for the case of additional drop path loss
(before this amplifier)
in order to hit a target power level (per carrier).
If both, the OSNR based on the ROADM
input power level
(Pcarrier =
Pref+10Log(carrier-baudrate/ref-baud) + delta-power)
and the input inferred NF(NF.drop),
and this OSNR value, are defined,
the minimum value between these two should be used";
}
leaf roadm-noise-figure {
type decimal64 {
fraction-digits 5;
}
units "dB";
description
"Drop path Noise Figure.
If the drop path contains an amplifier,
this is the noise figure
of that amplifier, inferred to the
ROADM ingress port.
This permits to determine
amplifier OSNR contribution
without having to specify the
ROADM node’s losses to that amplifier.
This applies for the case of no
additional drop path loss,
before the amplifier, in order to reduce the power
of the carriers to a target value";
}
}
}
grouping concentratedloss-params{
description "concentrated loss";
container concentratedloss{
description "concentrated loss";
leaf loss {
type decimal64 {
fraction-digits 2;
}
units dB ;
description "..";
}
}
}
grouping power-param{
description
"optical power or PSD after the ROADM or after the out-voa";
choice power-param {
description
"select the mode: channel power or power spectral density";
case channel-power {
/* when "equalization-mode='channel-power'"; */
leaf nominal-channel-power{
type decimal64 {
fraction-digits 1;
}
units dBm ;
description
" Reference channel power after the ROADM or after
the out-voa. ";
}
}
case power-spectral-density{
/* when "equalization-mode='power-spectral-density'"; */
leaf nominal-power-spectral-density{
type decimal64 {
fraction-digits 16;
}
units W/Hz ;
description
" Reference power spectral density after
the ROADM or after the out-voa.
Typical value : 3.9 E-14, resolution 0.1nW/MHz";
}
}
}
}
grouping oms-general-optical-params {
description "OMS link optical parameters";
leaf generalized-snr {
type l0-types-ext:snr;
description "generalized snr";
}
leaf equalization-mode{
type identityref {
base type-power-mode;
}
mandatory true;
description "equalization mode";
}
uses power-param;
}
grouping OTSiG {
description "OTSiG definition , representing client
digital information stream supported by 1 or more OTSi";
list otsi {
key "otsi-carrier-id";
config false;
description
"list of OTSi contained in 1 OTSiG.
The list could also be of only 1 element";
leaf otsi-carrier-id {
type int16;
description "OTSi carrier-id";
}
/*any OTSi as signal generated by transceiver and*/
/* attached to a transponder.*/
leaf transponder-ref {
type leafref {
path "/nw:networks/nw:network/nw:node/tet:te" +
"/tet:tunnel-termination-point" +
"/transponder/transponder-id";
}
description
"Reference to the configured transponder";
}
leaf transceiver-ref {
type leafref {
path "/nw:networks/nw:network/nw:node/tet:te" +
"/tet:tunnel-termination-point/"
+"transponder[transponder-id=current()"
+"/../transponder-ref]/"
+ "transceiver/transceiver-id" ;
}
description
"Reference to the configured transceiver " ;
}
leaf configured-mode {
type leafref {
path "/nw:networks/nw:network/nw:node/tet:te" +
"/tet:tunnel-termination-point/"
+"transponder[transponder-id=current()"
+"/../transponder-ref]/"+
"transceiver[transceiver-id=current()/"+
"../transceiver-ref]/supported-modes/"+
"supported-mode/mode-id";
}
description
"Reference to the configured mode for transceiver
compatibility approach";
}
uses l0-types-ext:common-transceiver-configured-param;
} // OTSi list
} // OTSiG grouping
grouping media-channel-groups {
description "media channel groups";
list media-channel-group {
key "i";
description
"list of media channel groups";
leaf i {
type int16;
description "index of media channel group member";
}
list media-channels {
key "flexi-n";
description
"list of media channels represented as (n,m)";
// this grouping add both n.m values
uses l0-types:flexi-grid-frequency-slot;
leaf OTSiG-ref {
type leafref {
path "/nw:networks/nw:network/nw:node/tet:te" +
"/tet:tunnel-termination-point" +
"/otsi-group/otsi-group-id" ;
}
description
"Reference to the otsi-group list to get otsi-group
identifier of the
OTSiG carried by this media channel
that reports the transient stat";
}
leaf OTSi-ref {
type leafref {
path "/nw:networks/nw:network/nw:node/tet:te" +
"/tet:tunnel-termination-point/"
+"otsi-group[otsi-group-id=current()"
+"/../OTSiG-ref]/"
+ "otsi/otsi-carrier-id" ;
}
description
"Reference to the otsi list supporting
the related OTSiG to get otsi identifier";
}
} // media channels list
} // media-channel-groups list
} // media media-channel-groups grouping
grouping oms-element {
description "OMS description";
list OMS-elements {
key "elt-index";
description
"defines the spans and the amplifier blocks of
the amplified lines";
leaf elt-index {
type uint16;
description
"ordered list of Index of OMS element
(whether it's a Fiber, an EDFA or a
Concentratedloss)";
}
leaf uid {
type string;
description
"unique id of the element if it exists";
}
leaf type {
type identityref {
base type-element;
}
mandatory true;
description "element type";
}
container element {
description "element of the list of elements of the OMS";
choice element {
description "OMS element type";
case amplifier {
/* when "type = 'Edfa'"; */
uses amplifier-params ;
}
case fiber {
/* when "type = 'Fiber'"; */
uses fiber-params ;
}
case concentratedloss {
/* when "type = 'Concentratedloss'"; */
uses concentratedloss-params ;
}
}
}
}
}
/* Data nodes */
augment "/nw:networks/nw:network/nw:network-types"
+ "/tet:te-topology" {
description "optical-impairment topology augmented";
container optical-impairment-topology {
presence "indicates an impairment-aware topology of
optical networks";
description
"Container to identify impairment-aware topology type";
}
}
augment "/nw:networks/nw:network/nt:link/tet:te"
+ "/tet:te-link-attributes" {
when "/nw:networks/nw:network/nw:network-types"
+"/tet:te-topology/"
+"optical-imp-topo:optical-impairment-topology" {
description
"This augment is only valid for Optical Impairment.";
}
description "Optical Link augmentation for impairment data.";
container OMS-attributes {
config false;
description "OMS attributes";
uses oms-general-optical-params;
uses media-channel-groups;
uses oms-element;
}
}
augment "/nw:networks/nw:network/nw:node/tet:te"
+ "/tet:tunnel-termination-point" {
when "/nw:networks/nw:network/nw:network-types"
+"/tet:te-topology/optical-imp-topo:optical-impairment-topology"{
description
"This augment is only valid for Impairment with non-sliceable
transponder model";
}
description
"Tunnel termination point augmentation for non-sliceable
transponder model.";
list otsi-group {
key "otsi-group-id";
config false;
description
"the list of possible OTSiG representing client digital
stream";
leaf otsi-group-id {
type int16;
description "index of otsi-group element";
}
uses OTSiG;
} // list of OTSiG
list transponder {
key "transponder-id";
config false;
description "list of transponder";
leaf transponder-id {
type uint32;
description "transponder identifier";
}
list transceiver {
key "transceiver-id";
config false;
description "list of transceiver related to a transponder";
leaf transceiver-id {
type uint32;
description "transceiver identifier";
}
uses l0-types-ext:transceiver-capabilities;
} // end of list of transceiver
} // end list of transponder
} // end of augment
augment "/nw:networks/nw:network/nw:node/tet:te"
+ "/tet:tunnel-termination-point" {
when "/nw:networks/nw:network/nw:network-types"
+"/tet:te-topology/"
+ "optical-imp-topo:optical-impairment-topology" {
description
"This augment is only valid for optical impairment
with sliceable transponder model";
}
description
"Tunnel termination point augmentation for sliceable
transponder model.";
uses sliceable-transponder-attributes;
}
augment "/nw:networks/nw:network/nw:node/tet:te"
+ "/tet:te-node-attributes" {
when "/nw:networks/nw:network/nw:network-types"
+ "/tet:te-topology"
+ "/optical-imp-topo:optical-impairment-topology" {
description
"This augment is only valid for Optical Impairment
topology";
}
description
"node attributes augmentantion for optical-impairment ROADM
node";
list roadm-path-impairments {
key "roadm-path-impairments-id";
config false;
description "list of set of optical impairments related
to ROADM ";
leaf roadm-path-impairments-id {
type uint32;
description "index of the ROADM path-impairment list";
}
choice impairment-type {
description "type path impairment";
case roadm-express-path {
uses roadm-express-path;
}
case roadm-add-path {
uses roadm-add-path;
}
case roadm-drop-path {
uses roadm-drop-path;
}
}
} // list path impairments
} // augmentation for optical-impairment ROADM
augment "/nw:networks/nw:network/nw:node/tet:te/"
+ "tet:information-source-entry/tet:connectivity-matrices"{
when "/nw:networks/nw:network/nw:network-types"
+ "/tet:te-topology/"
+ "optical-imp-topo:optical-impairment-topology" {
description
"This augment is only valid for Optical Impairment
topology ";
}
description
"Augment default TE node connectivity matrix information
source.";
leaf roadm-path-impairments {
type leafref {
path "../../../tet:te-node-attributes/"
+ "roadm-path-impairments/roadm-path-impairments-id";
}
description "pointer to the list set of ROADM optical
impairments";
}
} // augmentation connectivity-matrices information-source
augment "/nw:networks/nw:network/nw:node/tet:te/"
+ "tet:information-source-entry/tet:connectivity-matrices/"
+ "tet:connectivity-matrix" {
when "/nw:networks/nw:network/nw:network-types"
+ "/tet:te-topology/"
+ "optical-imp-topo:optical-impairment-topology" {
description
"This augment is only valid for Optical Impairment
topology ";
}
description
"Augment TE node connectivity matrix entry information
source.";
leaf roadm-path-impairments {
type leafref {
path "../../../../tet:te-node-attributes/"
+ "roadm-path-impairments/roadm-path-impairments-id";
}
description "pointer to the list set of ROADM optical
impairments";
}
} // augmentation connectivity-matrix information-source
augment "/nw:networks/nw:network/nw:node/tet:te/"
+ "tet:te-node-attributes/tet:connectivity-matrices" {
when "/nw:networks/nw:network/nw:network-types"
+ "/tet:te-topology/"
+ "optical-imp-topo:optical-impairment-topology" {
description
"This augment is only valid for Optical Impairment
topology ";
}
description
"Augment default TE node connectivity matrix.";
leaf roadm-path-impairments {
type leafref {
path "../../roadm-path-impairments/"
+ "roadm-path-impairments-id";
}
config false; /*the identifier in the list */
/*"roadm-path-impairments" of ROADM optical impairment*/
/*is read-only as the rest of attributes*/
description "pointer to the list set of ROADM optical
impairments";
}
} // augmentation connectivity-matrices
augment "/nw:networks/nw:network/nw:node/tet:te/"
+ "tet:te-node-attributes/"
+ "tet:connectivity-matrices/tet:connectivity-matrix" {
when "/nw:networks/nw:network/nw:network-types"
+ "/tet:te-topology/"
+ "optical-imp-topo:optical-impairment-topology" {
description
"This augment is only valid for
Optical Impairment topology ";
}
description
"Augment TE node connectivity matrix entry.";
leaf roadm-path-impairments {
type leafref {
path "../../../roadm-path-impairments/"
+ "roadm-path-impairments-id";
}
config false;
description "pointer to the list set of ROADM optical
impairments";
}
} // augmentation connectivity-matrix
augment "/nw:networks/nw:network/nw:node/tet:te/"
+ "tet:tunnel-termination-point/"
+ "tet:local-link-connectivities" {
when "/nw:networks/nw:network/nw:network-types"
+ "/tet:te-topology/"
+ "optical-imp-topo:optical-impairment-topology" {
description
"This augment is only valid for Optical Impairment topology ";
}
description
"Augment default TTP LLC.";
leaf add-path-impairments {
type leafref {
path "../../../tet:te-node-attributes/"
+ "roadm-path-impairments/roadm-path-impairments-id" ;
}
config false;
description "pointer to the list set of ROADM optical
impairments";
}
leaf drop-path-impairments {
type leafref {
path "../../../tet:te-node-attributes/"
+ "roadm-path-impairments/roadm-path-impairments-id" ;
}
config false;
description "pointer to the list set of ROADM
optical impairments";
}
} // augmentation local-link-connectivities
augment "/nw:networks/nw:network/nw:node/tet:te/"
+ "tet:tunnel-termination-point/"
+ "tet:local-link-connectivities/"
+ "tet:local-link-connectivity" {
when "/nw:networks/nw:network/nw:network-types"
+ "/tet:te-topology/"
+ "optical-imp-topo:optical-impairment-topology" {
description
"This augment is only valid for
Optical Impairment topology ";
}
description
"Augment TTP LLC entry.";
leaf add-path-impairments {
type leafref {
path "../../../../tet:te-node-attributes/"
+ "roadm-path-impairments/roadm-path-impairments-id" ;
}
config false;
description "pointer to the list set of ROADM optical
impairments";
}
leaf drop-path-impairments {
type leafref {
path "../../../../tet:te-node-attributes/"
+ "roadm-path-impairments/roadm-path-impairments-id" ;
}
config false;
description "pointer to the list set of ROADM optical
impairments";
}
} // augmentation local-link-connectivity
}
<CODE ENDS>¶
The configuration, state, and action data defined in this document are designed to be accessed via a management protocol with a secure transport layer, such as NETCONF [RFC6241]. The NETCONF access control model [RFC8341] provides the means to restrict access for particular NETCONF users to a preconfigured subset of all available NETCONF protocol operations and content.¶
A number of configuration data nodes defined in this document are read-only; however, these data nodes may be considered sensitive or vulnerable in some network environments (TBD).¶
This document registers the following namespace URIs in the IETF XML registry [RFC3688]:¶
-------------------------------------------------------------------- URI: urn:ietf:params:xml:ns:yang:ietf-optical-impairment-topology Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. --------------------------------------------------------------------¶
This document registers the following YANG modules in the YANG Module Names registry [RFC7950]:¶
-------------------------------------------------------------------- name: ietf-optical-impairment-topology namespace: urn:ietf:params:xml:ns:yang:ietf-optical-impairment- topology prefix: optical-imp-topo reference: RFC XXXX (TDB) --------------------------------------------------------------------¶
We thank Daniele Ceccarelli and Oscar G. De Dios for useful discussions and motivation for this work.¶
Aihua GuoHuawei Technologies¶
Email: aguo@futurewei.com¶
Jonas MartenssonRISE¶
Email: jonas.martensson@ri.se¶
Haomian ZhengHuawei Technologies¶
Email: zhenghaomian@huawei.com¶
Italo BusiHuawei Technologies¶
Email: Italo.Busi@huawei.com¶
Nicola SamboScuola Superiore Sant'Anna¶
Email: nicosambo@gmail.com¶
Giovanni MartinelliCisco¶
Email: giomarti@cisco.com¶
Esther Le RouzicOrange¶
Email: esther.lerouzic@orange.com¶
Julien MeuricOrange¶
Email: julien.meuric@orange.com¶
Sergio BelottiNokia¶
Email: Sergio.belotti@nokia.com¶
Griseri EnricoNokia¶
Email: Enrico.Griseri@nokia.com¶
Gert GrammelJuniper¶
Email: ggrammel@juniper.net¶