A YANG Data Model for Optical Impairment-aware Topology
draft-ietf-ccamp-optical-impairment-topology-yang-10
| Document | Type | Active Internet-Draft (ccamp WG) | |
|---|---|---|---|
| Authors | Dieter Beller , Esther Le Rouzic , Sergio Belotti , Gabriele Galimberti , Italo Busi | ||
| Last updated | 2022-07-11 | ||
| Replaces | draft-lee-ccamp-optical-impairment-topology-yang | ||
| Stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | (None) | ||
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| Yang Validation | 0 errors, 20 warnings | ||
| Additional resources |
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draft-ietf-ccamp-optical-impairment-topology-yang-10
CCAMP Working Group D. Beller, Ed.
Internet-Draft Nokia
Intended status: Standards Track E. Le Rouzic
Expires: 12 January 2023 Orange
S. Belotti
Nokia
G. Galimberti
Cisco
I. Busi
Huawei Technologies
11 July 2022
A YANG Data Model for Optical Impairment-aware Topology
draft-ietf-ccamp-optical-impairment-topology-yang-10
Abstract
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.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 12 January 2023.
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Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
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provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 5
1.3. Prefixes in Data Node Names . . . . . . . . . . . . . . . 5
2. Reference Architecture . . . . . . . . . . . . . . . . . . . 6
2.1. Control Plane Architecture . . . . . . . . . . . . . . . 6
2.2. Optical Transport Network Data Plane . . . . . . . . . . 7
2.3. OTS and OMS Media Channel Group . . . . . . . . . . . . . 7
2.3.1. Optical Tributary Signal (OTSi) . . . . . . . . . . . 8
2.3.2. Optical Tributary Signal Group (OTSiG) . . . . . . . 9
2.3.3. Media Channel (MC) . . . . . . . . . . . . . . . . . 10
2.3.4. Media Channel Group (MCG) . . . . . . . . . . . . . . 11
2.4. Amplifiers . . . . . . . . . . . . . . . . . . . . . . . 12
2.5. Transponders . . . . . . . . . . . . . . . . . . . . . . 14
2.5.1. Standard Modes . . . . . . . . . . . . . . . . . . . 15
2.5.2. Organizational Modes . . . . . . . . . . . . . . . . 15
2.5.3. Explicit Modes . . . . . . . . . . . . . . . . . . . 17
2.5.4. Transponder Capabilities and Current Configuration . 17
2.6. 3R Regenerators . . . . . . . . . . . . . . . . . . . . . 19
2.7. WSS/Filter . . . . . . . . . . . . . . . . . . . . . . . 22
2.8. Optical Fiber . . . . . . . . . . . . . . . . . . . . . . 22
2.9. WDM-Node Architectures . . . . . . . . . . . . . . . . . 22
2.9.1. Integrated WDM-node Architecture with Local Optical
Transponders . . . . . . . . . . . . . . . . . . . . 23
2.9.2. Integrated WDM-node with Integrated Optical
Transponders and Single Channel Add/Drop Interfaces for
Remote Optical Transponders . . . . . . . . . . . . . 24
2.9.3. Disaggregated WDM-TE-node Subdivided into Degree, Add/
Drop, and Optical Transponder Subsystems . . . . . . 25
2.9.4. Optical Impairments Imposed by WDM-TE-Nodes . . . . . 26
2.10. Protection Architectures . . . . . . . . . . . . . . . . 28
2.10.1. Individual OTSi Protection . . . . . . . . . . . . . 28
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2.10.2. OMS MCG protection . . . . . . . . . . . . . . . . . 29
3. YANG Model (Tree Structure) . . . . . . . . . . . . . . . . . 29
4. Optical Impairment Topology YANG Model . . . . . . . . . . . 35
5. Security Considerations . . . . . . . . . . . . . . . . . . . 64
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 65
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 65
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 65
8.1. Normative References . . . . . . . . . . . . . . . . . . 65
8.2. Informative References . . . . . . . . . . . . . . . . . 66
Appendix A. Contributors . . . . . . . . . . . . . . . . . . . . 68
Appendix B. Additional Authors . . . . . . . . . . . . . . . . . 69
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 69
1. Introduction
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.
It is worth noting that optical data plane interoperability is a
complex topic especially in a multi vendor environment and usually
requires joint engineering, which is independent from control plane
and management plane capabilities. The YANG data model defined in
this draft is providing sufficient information to enable optical
impairment aware path computation. Optical data plane
interoperability is outside the scope of this draft.
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This document augments the generic TE topology YANG model defined in
[RFC8795] where possible.
This document defines one YANG module: ietf-optical-impairment-
topology (Section 3) according to the new Network Management
Datastore Architecture [RFC8342].
1.1. Terminology
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:
* client
* server
* augment
* data model
* data node
The following terms are defined in [RFC6241] and are not redefined
here:
* configuration data
* state data
The terminology for describing YANG data models is found in
[RFC7950].
The term ROADM in this document refers to the term "multi-degree
reconfigurable optical add/drop multiplexer (MD-ROADM)" as defined in
[G.672]. It does not include local optical transponders, which can
be co-located in the same physical device (managed entity).
The term WDM-node refers to a physical device, which is managed as a
single network element.
The term WDM-TE-node refers to those parts of a WDM-node (physical
device) that are modeled as a TE-node as defined in [RFC8795], which
may include a ROADM and/or multiple local optical transponders(OTs).
Hence, a WDM-TE-node may only contain OTs.
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The term "WDM-TE-network" refers to a set of WDM-TE-nodes as defined
above that are interconnected via TE-links carrying WDM signals.
These TE-links may include optical amplifiers.
1.2. Tree Diagram
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].
1.3. Prefixes in Data Node Names
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- | ietf-optical- | [RFCXXXX] |
| topo | impairment- | |
| | topology | |
+--------------+---------------+-----------------------------------+
| layer0-types | ietf- | [RFC9093] |
| | layer0-types | |
+--------------+---------------+-----------------------------------+
| l0-types-ext | ietf-layer0- | [I-D.ietf-ccamp-layer0-types-ext] |
| | types-ext | |
+--------------+---------------+-----------------------------------+
| nw | ietf-network | [RFC8345] |
+--------------+---------------+-----------------------------------+
| nt | ietf-network- | [RFC8345] |
| | topology | |
+--------------+---------------+-----------------------------------+
| tet | ietf-te- | [RFC8795] |
| | topology | |
+--------------+---------------+-----------------------------------+
Table 1: Prefixes and corresponding YANG modules
[Editor's note: The RFC Editor will replace XXXX with the number
assigned to the RFC once this draft becomes an RFC.]
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2. Reference Architecture
2.1. Control Plane Architecture
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]
Figure 1: Scope of draft-ietf-ccamp-dwdm-if-param-yang
The topology model developed in this document is an abstracted
topology YANG model that can be used at 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].
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2.2. Optical Transport Network Data Plane
This section provides the description of the optical transport
network reference architecture and its relevant components to support
optical impairment-aware path computation.
Figure 2 shows the reference architecture.
+-------------------+ +-------------------+
| WDM-Node | | WDM-Node |
| | | |
| PA +-------+ BA | ILA | PA +-------+ BA |
| +-+ | | +-+ | _____ +--+ _____ | +-+ | | +-+ |
--|-| |-| ROADM |-| |-|-()____)-| |-()____)-|-| |-| ROADM |-| |-|--
| +-+ | | +-+ | +--+ | +-+ | | +-+ |
| +-------+ | optical | +-------+ |
| | | | | fiber | | | | |
| o o o | | o o o |
| local | | local |
| transponders | | transponders |
+-------------------+ +-------------------+
OTS MCG OTS MCG
<---------> <--------->
OMS MCG = TE-link
<-------------------------------->
BA: Booster Amplifier (or egress amplifier)
PA: Pre-Amplifier (or ingress amplifier)
ILA: In-Line Amplifier
MCG: Media Channel Group
Figure 2: Reference Architecture for Optical Transport Network
BA (on the left side WDM-TE-node) is the engress Amplifier and PA (on
the right side WDM-TE-node is the ingress amplifier for the OMS Media
Channel Group (MCG) Figure 2.
2.3. OTS and OMS Media Channel Group
According to [G.807] and [G.872], an OTS Media Channel Group (MCG)
represents a topological construct between two adjacent amplifiers,
such as:
(i) between a WDM-TE-node's BA and the adjacent ILA,
(ii) between a pair of ILAs,
(iii) between an ILA and the adjacent WDM-TE-node's PA.
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According to [G.807] and [G.872], an OMS Media Channel Group (MCG)
represents a topological construct between two WDM-TE-nodes.
Specifically, it originates at the ROADM in the source WDM-TE-node
and terminates at the ROADM in the destination WDM-TE-node including
the Booster Amplifier (BA) and the Pre-Amplifier (PA) in the WDM-TE-
nodes as well as the In-Line Amplifiers (ILAs) between the two WDM-
TE-nodes.
An OMS MCG can be decomposed into a sequence of OTS MCGs and
amplifiers.
An OMS MCG can be described as a sequence of elements such as BA,
fiber section, ILA, PA, and concentrated loss wherever there is an
insertion loss caused for example by a fiber connector.
In TE-topology terms, the OMS MCG is modeled as a WDM TE-link
interconnecting two WDM-TE-nodes. A network controller can retrieve
the optical impairment data for all the WDM TE-link elements defined
in the layer-0 topology YANG model.
The optical impairments related to the link between remote optical
transponders, located in a different WDM-TE-node (an IP router with
integrated optical transponders for example), can also be modeled as
a WDM TE-link using the same optical impairments as those defined for
a WDM TE-link between WDM-TE-nodes (OMS MCG). In this scenario, the
node containing the remote optical transponders can be considered as
WDM-TE-node with termination capability only and no no switching
capabilities.
An OMS MCG is terminated on both ends by a link termination point
(LTP) as defined in [RFC8345]. Links in optical transport networks
are typically bidirectional but have to be modeled as a pair of two
unidirectional links following the [RFC8345] modeling approach.
Unlike TE-links, which are unidirectional, the LTPs on either end of
the TE-link pair forming the bidirectional link, are bidirectional as
described in [I-D.ietf-teas-te-topo-and-tunnel-modeling] and the pair
of unidirectional links are connected to the same bidirectional LTP
on either end of the link pair.
2.3.1. Optical Tributary Signal (OTSi)
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
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shaping (e.g. raised cosine - complying with the Nyquist inter symbol
interference criterion), etc.
Path computation needs to know the existing OTSi signals for each OMS
link in the topology to determine the optical impairment impact of
the existing OTSi signals on the optical feasibility of a new OTSi
signal and vice versa, i.e., the impact of the new OTSi on the
existing OTSi signals. For determining the optical feasibility of
the new OTSi, it is necessary to know the OTSi properties like
carrier frequency, baud rate, and signal power for all existing OTSi
signals on each OMS link.
Additionally, it is necessary for each WDM-TE-node in the network to
know the OTSi signals that are added to or dropped from an WDM TE-
link (OMS MCG)link as well as the optical power of these OTSi signals
to check whether the WDM-TE-node's optical power constraints are met.
The optical impairment-aware topology YANG model below defines the
OTSi properties needed for optical impairment-aware path computation
including the spectrum occupied by each OTSi signal. The model also
defines a pointer (leafref) from the OTSi to the transceiver module
terminating the OTSi signal.
The OTSi signals in the YANG model are described by augmenting the
network and each OTSi signal is uniquely identified by its otsi-
carrier-id, which is unique within the scope the OTSiG [see
Section 2.3.2 below] the OTSi belongs to.
2.3.2. Optical Tributary Signal Group (OTSiG)
The OTSiG is defined in ITU-T Recommendation G.807 [G.807] as a "set
of optical tributary signals (OTSi) that supports a single digital
client". Hence, 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 [G.807], section 10.2. The YANG model below
supports both cases: the single OTSi case where the OTSiG contains a
single OTSi (see [G.807], Figure 10-2) and the multiple OTSi case
where the OTSiG consists of more than one OTSi (see [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.
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All OTSiGs are described in the YANG model by augmenting the network
and each OTSiG is uniquely identified by its otsi-group-id, which is
unique within the network. Each OTSiG also contains a list of the
OTSi signals belonging to the OTSiG.
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
Figure 3: MC Example containing all 4 OTSi signals of an OTSiG
2.3.3. Media Channel (MC)
[G.807] defines a "media channel" as "A media association that
represents both the topology (i.e., the path through the media) and
the resource (i.e., frequency slot or effective frequency slot) that
it occupies." In this document, the term "channel" is occasionally
used to indicate the resource of an MC (i.e., frequency slot or
effective frequency slot), without representing topology.
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.
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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 ----------------------->
Figure 4: Figure Caption TBA
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 [G.694.1]. In this
model, the effective frequency slot as defined in [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.
2.3.4. Media Channel Group (MCG)
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.
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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
Figure 5: Figure Caption TBA
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).
2.4. Amplifiers
Optical amplifiers are used in WDM networks for amplifying the
optical signal in the optical domain without any optical to
electrical and electrical to optical conversion. There are three
main optical amplifier technologies:
* Erbium Doped Fiber Amplifiers (EDFAs)
* Raman Amplifiers
* Semiconductor Optical Amplifiers (SOAs)
In today's WDM networks EDFAs and Raman amplifiers are widely used.
Raman amplifiers have become attractive due to their large spectral
gain bandwidth, which can be quite flat, with similar or even lower
noise figures compared to EDFAs. On the other hand, Raman amplifiers
consume more power and are usually more expensive than EDFAs.
Raman amplifiers are distributed amplifiers where an optical pump
signal is injected typically in opposite direction to the optical
signal that is amplified (backward pump, counter-propagating pump
light). Injecting the optical pump signal in the same direction is
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also possible (forward pump, co-propagating pump light). For optical
amplifiers, the YANG model defines Raman pump light attributes
describing the direction (raman-direction) with respect to the signal
that is amplified and optical frequency and power for the pump light
source(s) contained in the raman-pump list. These Raman amplifier-
specific attributes are optional as they are only applicable to Raman
amplifiers. For determining the optical amplifier type, i.e., to
figure out whether an optical amplifier is a Raman amplifier, the
type-variety attribute is used. Due to the distributed nature of the
Raman amplifier it is difficult to clearly separate the amplifier
from the fiber span into which the pump signal is injected. From a
topology modeling perspective, the Raman amplifier is modeled as two
OMS line elements:
1. a passive fiber element accounting for the fiber loss only and
not the resulting loss including the Raman gain
2. an amplifier element providing all optical amplifier properties
(gain, tilt, etc.). On the OMS-link, the amplifier element is
placed where the pump is located and the geolocation information
also indicates the location of the pump.
Amplifiers can be classified according to their location along the
TE-link (OMS MCG). There are three basic amplifier types: In-Line
Amplifiers, Pre-Amplifiers and Booster Amplifiers. ILAs are separate
physical devices while Pre-Amplifiers and Booster Amplifiers are
integral elements of a WDM-node. From a data modeling perspective,
node-internal details should not be modeled and should be abstracted
as much as possible. For Pre-Amplifiers and Booster Amplifiers,
however, a different approach has been taken and they are modeled as
TE-link elements as they have the same optical impairments as ILAs.
ILAs are placed at locations where the optical amplification of the
WDM signal is required on the TE-link (OMS MCG) between two WDM-TE-
nodes nodes. Geolocation information is already defined for TE nodes
in [RFC8795] and is also beneficial for ILAs. Therefore, the same
geolocation container has been added to the amplifier element on an
OMS link containing altitude, latitude, and longitude as optional
attributes.
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).
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2.5. Transponders
[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
transceiver modules. A transceiver represents a transmitter/receiver
(Tx/Rx) pair as defined in ITU-T Recommendation G.698.2 [G.698.2].
In addition to the transceiver, which is terminating an OTSi signal,
a transponder typically provides additional layer 1 functionality
like for example aggregation (multiplexing) of client layer signals,
which is outside the scope of this document addressing layer 0
aspects of transponders.
The termination of an OTSi signal by a transceiver is modeled as a
function of the tunnel termination point (TTP) as defined in
[RFC8795]. Due to the fact that optical transport services (TE
tunnels) are typically bidirectional, a TTP is also modeled as a
bidirectional entity like the LTP described above. Moreover, a TTP
can terminate one or several OTSiG signals (tunnels) as described in
[I-D.ietf-teas-te-topo-and-tunnel-modeling] and each OTSiG consists
of one or multiple OTSi signals as described in Section 2.3.2.
Therefore, a TTP may be associated with multiple transceiver modules.
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:
* Standard Modes
* Organizational Modes
* Explicit Modes
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2.5.1. Standard Modes
A standard mode is related to an optical specification developed by
an SDO organization. Currently, the "Standard Modes" can only be
referred to ITU-T G.698.2 [G.698.2] since G.698.2 is the only
specification defining "Standard Modes" today. Nothing is
precluding, however, to consider other specifications provided by any
other SDO in the Standard Mode context as soon as such sepcifications
will be available. An application code as defined in ITU-T G.698.2
[G.698.2] is representing 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. As the characteristics are
encoded in the application code, the YANG model in this document only
defines a string, which represents that application code.
2.5.2. Organizational Modes
Organizations like operator groups, industry fora, or equipment
vendors can define their own optical interface specifications and
make use of transceiver capabilities going beyond existing standards.
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. It is the
responsibility of the organization to assign operational modes and to
ensure that operational modes are unique and unambiguous within the
scope of the organization.
Two transceivers can be interconnected, 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 defined by the optical interface specification - these
properties are not provided for anoperational mode and are therefore
not defined in the YANG model. Examples of these properties are:
* FEC type
* Modulation scheme
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* Encoding (mapping of bit patterns (code words) to symbols in the
constellation diagram)
* Baud rate (symbol rate)
* Carrier bandwidth (typically measured in GHz)
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.
An organization may define the operational modes to include the
optical power and carrier frequency related properties following the
application code approach as defined in ITU-T Recommendation G.698.2
[G.698.2]. In such a case, the explicit optical power and carrier
frequency related optional attributes shall be omitted in order to
avoid redundant information in the description of the transceiver
capabilities. If these attributes are provided in addition to the
operational modes including these attribute values implicitly, the
parameter values provided explicitly replace the implicit values and
take precedence. This shall, however, only be an done in exceptional
cases and shall be avoided whenever possible. In case an implicitly
given range is extended utilizing the explicit optional attributes, a
path computation policy rule may be applied to select a value
preferably from the range defined implicitly and to only select a
value from the extended range if no path can be found for values in
the implicitly defined range. Path computation policy is outside the
scope of this topology YANG model.
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In summary, the optical power and carrier frequency related
attributes shall either be described implicitly by the operational
mode following the definition provided by that organization or shall
be described explicitly when the optical power and carrier frequency
related properties are not included in the operational mode
definition.
2.5.3. Explicit Modes
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.
2.5.4. Transponder Capabilities and Current Configuration
The YANG model described in Section 3 defines the optical transceiver
properties. They are divided between:
a. Optical transceiver capabilities, describing how it can be
configured
b. Current transceiver setting, indicating how it is currently
configured
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:
* Supported transmitter tuning range with min/max nominal carrier
frequency [f_tx_min, f_tx_max]
* Supported transmitter tunability describing the transmitter's
frequency fine tuning steps (the minimum distance between two
adjacent carrier frequencies in GHz)
* Supported transmitter power range [p_tx-min, p_tx_max]
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* Supported receiver channel power range [p_rx-min, p_rx_max]
* Supported maximum total power, rx power for all channels fed into
the receiver
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:
* Pointer to the transponder instance containing the transceiver
terminating the OTSi
* Pointer to the transceiver instance terminating the OTSi
* Pointer to the currently configured transceiver mode
Additionally, the OTSi is described by the following frequency and
optical power related attributes:
* current carrier-frequency
* currently transmitted channel power
* currently received channel power
* currently received total power
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2.6. 3R Regenerators
Optical transponders are usually used to terminate a layer 0 tunnel
(layer 0 service) in the WDM layer. If, however, no optical path can
be found from the source transponder to the destination transponder
that is optically feasible due to the optical impairments, one or
more 3R regenerators are needed for regenerating the optical signal
in intermediate nodes. The term "3R" regenerator means:
reamplification, reshaping, retiming. As described in [G.807],
Appendix IV, a 3R regenerator terminates the OTSi and generates a new
OTSi. Depending on the 3R regenerator capabilities, it can provide
functions such as carrier frequency translation (carrier-frequency),
changes in the modulation scheme (modulation-type) and FEC (FEC-type)
while passing through the digital signal except the FEC (the FEC is
processed and errors are corrected).
The 3R regeneartion compound function is illustrated in section 10.1
of [G.798.1], and sections 10.3 and 10.4 provide examples of a ROADM
architecture and a photonic cross-connect architecture including 3R
regenerators. Based on the provided functionality, 3R regenerators
are considered as topological layer 0 entities because they are
needed for layer 0 path computation in case the optical impairments
make it impossible to find an optically feasible end-to-end path from
the source transponder to the destination transponder without 3R
regeneration. When an end-to-end path includes one or more 3R
regenerators, the corresponding layer 0 tunnel is subdivided into 2
or more segments between the source transponder and the destination
transponder terminating the layer 0 tunnel.
3R regenerators are usually realized by a pair of optical
transponders, which are described in Section 2.5 above. If a pair of
optical transponders is used to perform a 3R regeneratator function,
two different configurations are possible involving the pair of
optical transceivers of the two optical transponders:
* The two transponders can be operated in a back-to-back
configuration where the transceiver of each optical transponder
receives and transmits the optical signal from/to the same segment
of the end-to-end tunnel. This means that each transceiver is
operated in a bi-directional mode.
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Optical Transponder 1 Optical Transponder 2
+-----------------------+ +-----------------------+
| Transceiver | | Transceiver |
|-------------+ +-----| |-----+ +-------------|
--->| Receiver |---|Sig. |--->|Sig. |---| Transmitter |--->
|-------------+ | | | | +-------------|
<---| Transmitter |---|Proc.|<---|Proc.|---| Receiver |<---
|-------------+ +-----| |-----+ +-------------|
| | | |
+-----------------------+ +-----------------------+
Sig. Proc. = Signal Processing
Figure 6: Back-to-back 3R Regenerator Example
* The two transponders can be operated in a configuration where each
transponder performs the 3R regeneration function in one
direction, one in forward direction (from source to destination)
and the other in the reverse direction. In this configuration,
the transceiver of each optical transponder receives the signal
from one segment and transmits the regenerated optical signal into
the adjacent segment. This configuration is also called cross-
regeneration and each transceiver is operated in an uni-
directional mode.
Implemantations may support the change of the carrier frequency
where the receiver may operate at a different optical frequency as
the transmitter. The transceiver mode is a property of the
transceiver and is applied to the transmitter and the receiver.
Therefore, the transceiver mode is the same for the two segments
on the two sides of the 3R regenaretor realised by two
transceivers operated in the uni-directional mode.
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Optical Transponder 1
+-----------------------------+
| Transceiver |
|-------------+ +---------+ |
--->| Receiver |---|Sig. --+ | |
|-------------+ | | | |
<---| Transmitter |---|Proc.<-+ | |
|-------------+ +---------+ |
| |
+-----------------------------+
3R in forward direction
Optical Transponder 2
+-----------------------------+
| Transceiver |
|-------------+ +---------+ |
--->| Receiver |---|Sig. --+ | |
|-------------+ | | | |
<---| Transmitter |---|Proc.<-+ | |
|-------------+ +---------+ |
| |
+-----------------------------+
3R in reverse direction
Sig. Proc. = Signal Processing
Figure 7: Cross-3R Regenerator Example
Due to the fact that 3R regenerators are composed of an optical
transponder pair, the capabilitiy whether an optical transponder can
be used as a 3R regenerator is is added to the transponder
capabilities. Hence, no additional entity is required for describing
3R regenerators in the TE-topology YANG model. The optical
transonder capabilities regarding the 3R regenerator function are
described by the following two YANG model attributes:
* supported-termination-type
* supported-3r-mode
The supported-termination-type attribute describes whether the
optical transponder can be used as tunnel terminating transponder
only, as 3R regenerator only, or whether it can support both
functions. The supported-3r-mode attrbute describes the
configuration of the transponder pair forming the 3R regeneartor as
described above.
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More text to be added here!
2.7. WSS/Filter
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.
2.8. Optical Fiber
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.
2.9. WDM-Node Architectures
The WDM-node architectures in today's dense wavelength division
multiplexing (DWDM) networks can be categorized as follows:
* Integrated WDM-node architecture with local optical transponders
* Integrated WDM-node architecture with local optical transponders
and single channel add/drop ports for remote optical transponders
* Disaggregated WDM-node architecture where the WDM-TE-node is
composed of degree, add/drop, and optical transponder subsystems
handled as separate WDM-nodes
The TE topology YANG model augmentations including optical
impairments for DWDM networks defined below intend to cover all the 3
categories of WDM-node architectures listed above. In the case of a
disaggregated WDM-node architecture, it is assumed that the optical
domain controller already performs some form of abstraction and
presents the WDM-TE-node representing the disaggregated WDM-node in
the same way as an integrated WDM-TE-node with local optical
transponders if the optical transponder subsystems and the add/drop
subsystems are collocated (short fiber links not imposing any
significant optical impairments).
The different WDM-node architectures are briefly described and
illustrated in the following subsections.
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[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 WDM-TE-node requires further
investigations and will be addressed in a future revision of this
document.]
2.9.1. Integrated WDM-node Architecture with Local Optical Transponders
Figure 2 and Figure 8 below show the typical architecture of an
integrated WDM-node, which contains the optical transponders as an
integral part of the WDM-node. Such an integrated WDM-node provides
DWDM interfaces as external interfaces for interconnecting the device
with its neighboring WDM-node (see OMS MCG above). The number of
these interfaces denote also the degree of the WDM-node. A degree 3
WDM-node for example has 3 DWDM links that interconnect the WDM-node
with 3 neighboring WDM-nodes. Additionally, the WDM-node provides
client interfaces for interconnecting the WDM-node with client
devices such as IP routers or Ethernet switches. These client
interfaces are the client interfaces of the integrated optical
transponders.
. . . . . . . . . . . . . . . . . .
. WDM-TE-Node .
+-----.-------------------------------- .-----+
| . WDM-Node . |
| . /| +-----------------+ |\ . |
Line | . / |--| |--| \ . | Line
WEST | /| . | |--| |--| | . |\ | EAST
------+-/ |-.-| |--| photonic |--| |-.-| \-+-----
------+-\ |-.-| |--| cross-connect |--| |-.-| /-+-----
| \| . | |--| |--| | . |/ |
| . \ |--| |--| / . |
| . \| +-----------------+ |/ . |
| . . |
| . +---+ +---+ +---+ +---+ . |
| . | O | | O | | O | | O | . |
| . | T | | T | | T | | T | . |
| . +---+ +---+ +---+ +---+ . |
| . | | | | | | | | . |
+-----.------+-+---+-+---+-+---+-+------.-----+
. . . .|.| . |.| . |.| . |.|. . . .
| | | | | | | |
Client Interfaces
Figure 8: Integrated WDM-node Architectiure with Local Transponders
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2.9.2. Integrated WDM-node with Integrated Optical Transponders and
Single Channel Add/Drop Interfaces for Remote Optical
Transponders
Figure 9 below shows the extreme case where all optical transponders
are not integral parts of the WDM-node but are separate devices that
are connected to the add/drop ports of the WDM-node. If the optical
transponders and the WDM-node are collocated and if short single
channel fiber links are used to interconnect the optical transponders
with an add/drop port of the WDM-node, the optical domain controller
may present these optical transponders in the same way as local
optical transponders. If, however, the optical impairments of the
single channel fiber link between the optical transponder and the
add/drop port of the WDM-node 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].
. . . . . . . . . . . . . . . . . .
. WDM-TE-Node .
+-----.-------------------------------- .-----+
| . WDM-Node . |
| . /| +-----------------+ |\ . |
Line | . / |--| |--| \ . | Line
WEST | /| . | |--| |--| | . |\ | EAST
------+-/ |-.-| |--| photonic |--| |-.-| \-+-----
------+-\ |-.-| |--| cross-connect |--| |-.-| /-+-----
| \| . | |--| |--| | . |/ |
| . \ |--| |--| / . |
| . \| +-----------------+ |/ . |
+-----.---------|----|---|----|---------.-----|
Colored OT . +-+ ++ ++ +-+ .
line I/F . | | | | .
. +---+ +---+ +---+ +---+ .
. | O | | O | | O | | O | .
. | T | | T | | T | | T | .
. +---+ +---+ +---+ +---+ .
. . . .|.| . |.| . |.| . |.|. . . .
| | | | | | | |
Client Interfaces
Figure 9: Integrated WDM-node Architectiure with Remote Transponders
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2.9.3. Disaggregated WDM-TE-node Subdivided into Degree, Add/Drop, and
Optical Transponder Subsystems
Recently, some DWDM network operators started demanding WDM
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 WDM-TE-node are:
* Single degree subsystems
* Add/drop subsystems
* Optical transponder subsystems
These subsystems are 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 WDM-TE-node. This
disaggregated WDM-TE-node architecture is depicted in Figure 10
below.
As this document defines TE topology YANG model augmentations
[RFC8795] 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 WDM-TE-node and presents the disaggregated WDM-TE-node
in the same way as an integrated WDM-node hiding all the
interconnects that are not relevant from an external TE topology
view.
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. . . . . . . . . . . . . . . . . .
. WDM-TE-Node .
+-----.----------+ +----------.-----+
| 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 | .
. +---+ +---+ +---+ +---+ .
. . .|.| . |.| . |.| . |.|. . .
| | | | | | | |
Client Interfaces
Figure 10: Disaggregated WDM-TE-node Architecture with Remote
Transponders
2.9.4. Optical Impairments Imposed by WDM-TE-Nodes
[Editor's note: the following text still needs to be updated based on
the agreed terminology]
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:
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* Chromatic dispersion (CD)
* Polarization mode dispersion (PMD)
* Polarization dependent loss (PDL)
* Optical amplifier noise due to amplified spontaneous emission
(ASE)
* In-band cross-talk
* Filtering effects (for further study)
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:
* Express path: MC path between two line ports of the ROADM
(unidirectional)
* Add Path: MC path from an Add port to a line port of the ROADM
* Drop path: MC path from a line port to a Drop port of the ROADM
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 [RFC8795]. 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
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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).
[RFC8795] 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]
2.10. Protection Architectures
The YANG model defined in this document supports the following
protection architectures:
* Individual OTSi protection
* OMS MCG protection = TE-link protection between adjacent WDM-TE-
nodes
[Editor's note: this section is still work in progress]
2.10.1. Individual OTSi Protection
Individual OTSi protection is a protection architecture where an
individual OTSi signal is protected as defined in Appendix III of
ITU-T Recommendation G.873.1 [G.873.1]. This protection architecture
requires dedicated photonic protection functions that are typically
provided by dedicated protection hardware. These photonic protection
functions are a photonic splitter function splitting the OTSi signal
in transmit direction and a photonic selector function selecting the
OTSi signal in receive direction from one of the two protection legs
between the protection functions terminating the individual OTSi
protection. This individual OTSi protection scheme can be considered
as a photonic 1+1 protection scheme (1+1 sub-network connection
protection (SNCP) in ITU-T terminology).
In case of individual OTSi protection, there are two network media
channel paths associated with the OTSi signal. In the YANG model,
this is modeled as a leaf list of the otsi providing the nmc-path-id
for the two network media channel paths associated with the
individually protected otsi.
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[Editor's note: this section is still work in progress]
2.10.2. OMS MCG protection
OMS MCG protection is a protection architecture where a TE-link
between two adjacent WDM-TE-nodes is protected. This is a local
protection scheme, which can be modeled as a TE-link property.
[Editor's note: this section is still work in progress]
3. YANG Model (Tree Structure)
[Editor's note: tree view below always has to be updated before
submitting a new revision!]
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:
+--ro otsi-group* [otsi-group-id]
+--ro otsi-group-id string
+--ro otsi* [otsi-carrier-id]
+--ro otsi-carrier-id uint16
+--ro otsi-carrier-frequency? union
+--ro nmc-path-id* uint16
augment /nw:networks/nw:network/nw:node:
+--ro transponder* [transponder-id]
| +--ro transponder-id uint32
| +--ro termination-type-capabilities? enumeration
| +--ro supported-3r-mode? enumeration
| +--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?
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| | | | frequency-thz
| | | +--ro transceiver-tunability?
| | | | 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 bitrate?
| | | uint16
| | +--ro max-polarization-mode-dispersion?
| | | decimal64
| | +--ro max-chromatic-dispersion?
| | | decimal64
| | +--ro chromatic-dispersion-penalty* []
| | | +--ro chromatic-dispersion union
| | | +--ro penalty-value union
| | +--ro polarization-dispersion-penalty* []
| | | +--ro polarization-mode-dispersion
| | | | union
| | | +--ro penalty-value
| | | union
| | +--ro max-diff-group-delay?
| | | int32
| | +--ro max-polarization-dependent-loss-penalty* []
| | | +--ro max-polarization-dependent-loss
| | | | power-in-db-or-null
| | | +--ro penalty-value
| | | union
| | +--ro available-modulation-type?
| | | identityref
| | +--ro min-OSNR?
| | | snr
| | +--ro min-Q-factor?
| | | int32
| | +--ro available-baud-rate?
| | | uint32
| | +--ro roll-off?
| | | decimal64
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| | +--ro min-carrier-spacing?
| | | frequency-ghz
| | +--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 transceiver-tunability?
| | | 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
| +--ro configured-mode?
| | -> ../supported-modes/supported-mode/mode-id
| +--ro tx-channel-power? union
| +--ro rx-channel-power? union
| +--ro rx-total-power? union
| +--ro outgoing-otsi
| | +--ro otsi-group-ref?
| | | -> ../../../../../otsi-group/otsi-group-id
| | +--ro otsi-ref? leafref
| +--ro incoming-otsi
| | +--ro otsi-group-ref?
| | | -> ../../../../../otsi-group/otsi-group-id
| | +--ro otsi-ref? leafref
| +--ro configured-termination-type? enumeration
+--ro regen-group* [group-id]
+--ro group-id uint32
+--ro regen-metric? uint32
+--ro transponder-ref* -> ../../transponder/transponder-id
augment /nw:networks/nw:network/nt:link/tet:te
/tet:te-link-attributes:
+--ro OMS-attributes
+--ro generalized-snr? l0-types:snr
+--ro equalization-mode identityref
+--ro (power-param)?
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| +--:(channel-power)
| | +--ro nominal-carrier-power?
| | l0-types:power-in-dbm-or-null
| +--:(power-spectral-density)
| +--ro nominal-power-spectral-density? union
+--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 otsi-group-ref?
| | -> /nw:networks/network/otsi-group/otsi-group-id
| +--ro otsi-ref* []
| | +--ro otsi-carrier-ref? leafref
| | +--ro nmc-path-ref* leafref
| +--ro delta-power? l0-types:power-in-dbm-or-null
+--ro OMS-elements* [elt-index]
+--ro elt-index uint16
+--ro oms-element-uid? union
+--ro reverse-element-ref
| +--ro link-ref?
| | -> ../../../../../../../nt:link/link-id
| +--ro oms-element-ref* leafref
+--ro (element)
+--:(amplifier)
| +--ro geolocation
| | +--ro altitude? int64
| | +--ro latitude? geographic-coordinate-degree
| | +--ro longitude? geographic-coordinate-degree
| +--ro amplifier
| +--ro type-variety string
| +--ro operational
| +--ro amplifier-element* []
| +--ro name?
| | string
| +--ro frequency-range
| | +--ro lower-frequency frequency-thz
| | +--ro upper-frequency frequency-thz
| +--ro actual-gain
| | l0-types:power-in-db-or-null
| +--ro tilt-target
| | l0-types:decimal-2-digits-or-null
| +--ro out-voa
| | l0-types:power-in-db-or-null
| +--ro in-voa
| | l0-types:power-in-db-or-null
| +--ro total-output-power
| | l0-types:power-in-db-or-null
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| +--ro (power-param)?
| | +--:(channel-power)
| | | +--ro nominal-carrier-power?
| | | l0-types:power-in-dbm-or-null
| | +--:(power-spectral-density)
| | +--ro nominal-power-spectral-density?
| | union
| +--ro raman-direction?
| | enumeration
| +--ro raman-pump* []
| +--ro frequency? l0-types:frequency-thz
| +--ro power?
| l0-types:decimal-2-digits-or-null
+--:(fiber)
| +--ro fiber
| +--ro type-variety string
| +--ro length
| | l0-types:decimal-2-digits-or-null
| +--ro loss-coef
| | l0-types:decimal-2-digits-or-null
| +--ro total-loss l0-types:power-in-db-or-null
| +--ro pmd?
| | l0-types:decimal-2-digits-or-null
| +--ro conn-in? l0-types:power-in-db-or-null
| +--ro conn-out? l0-types:power-in-db-or-null
+--:(concentratedloss)
+--ro concentratedloss
+--ro loss l0-types:power-in-db-or-null
augment /nw:networks/nw:network/nw:node/tet:te
/tet:tunnel-termination-point:
+--ro ttp-transceiver* [transponder-ref transceiver-ref]
+--ro transponder-ref
| -> ../../../../transponder/transponder-id
+--ro transceiver-ref leafref
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 frequency-range
| | +--ro lower-frequency frequency-thz
| | +--ro upper-frequency frequency-thz
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| +--ro roadm-pmd? union
| +--ro roadm-cd? union
| +--ro roadm-pdl?
| | l0-types:power-in-db-or-null
| +--ro roadm-inband-crosstalk?
| | l0-types:power-in-db-or-null
| +--ro roadm-maxloss?
| l0-types:power-in-db-or-null
+--:(roadm-add-path)
| +--ro roadm-add-path* []
| +--ro frequency-range
| | +--ro lower-frequency frequency-thz
| | +--ro upper-frequency frequency-thz
| +--ro roadm-pmd? union
| +--ro roadm-cd? union
| +--ro roadm-pdl?
| | l0-types:power-in-db-or-null
| +--ro roadm-inband-crosstalk?
| | l0-types:power-in-db-or-null
| +--ro roadm-maxloss?
| | l0-types:power-in-db-or-null
| +--ro roadm-pmax?
| | l0-types:power-in-dbm-or-null
| +--ro roadm-osnr? l0-types:snr-or-null
| +--ro roadm-noise-figure? union
+--:(roadm-drop-path)
+--ro roadm-drop-path* []
+--ro frequency-range
| +--ro lower-frequency frequency-thz
| +--ro upper-frequency frequency-thz
+--ro roadm-pmd? union
+--ro roadm-cd? union
+--ro roadm-pdl?
| l0-types:power-in-db-or-null
+--ro roadm-inband-crosstalk?
| l0-types:power-in-db-or-null
+--ro roadm-maxloss?
| l0-types:power-in-db-or-null
+--ro roadm-minloss?
| l0-types:power-in-db-or-null
+--ro roadm-typloss?
| l0-types:power-in-db-or-null
+--ro roadm-pmin?
| l0-types:power-in-dbm-or-null
+--ro roadm-pmax?
| l0-types:power-in-dbm-or-null
+--ro roadm-ptyp?
| l0-types:power-in-dbm-or-null
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+--ro roadm-osnr? l0-types:snr-or-null
+--ro roadm-noise-figure? union
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
+--ro llc-transceiver* [ttp-transponder-ref ttp-transceiver-ref]
+--ro ttp-transponder-ref
| -> ../../../../ttp-transceiver/transponder-ref
+--ro ttp-transceiver-ref
| -> ../../../../ttp-transceiver/transceiver-ref
+--ro is-allowed? boolean
+--ro add-path-impairments? leafref
+--ro drop-path-impairments? leafref
4. Optical Impairment Topology YANG Model
[Editor's note: YANG code below always has to be updated before
submitting a new revision!]
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<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";
}
organization
"IETF CCAMP Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/ccamp/>
WG List: <mailto:ccamp@ietf.org>
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
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"This module contains a collection of YANG definitions for
impairment-aware optical networks.
Within this module, if the value of a mandatory attribute is
unknown, it MUST be reported using the empty type.
If an optional attribute is applicable but its value is unknown,
it MUST be reported using the empty type.
If an optional attribute is not applicable to an entity, it MUST
be omitted (not be present in the datastore).
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED',
'MAY', and 'OPTIONAL' in this document are to be interpreted as
described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
they appear in all capitals, as shown here.
Copyright (c) 2022 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 Revised BSD
License set forth in Section 4.c of the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://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 2022-07-06 {
description
"Initial Version";
reference
"RFC XXXX: A Yang Data Model for Impairment-aware
Optical Networks";
}
// grouping
grouping sliceable-transponder-attributes {
description
"Configuration of a sliceable transponder.";
list sliceable-transponder-list {
key "carrier-id";
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config false;
description "List of carriers";
leaf carrier-id {
type uint32;
config false;
description "Identifier of the carrier";
}
}
}
/*
* 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 operational parameters";
list amplifier-element {
description
"The list of parallel amplifier elements within an
amplifier used to amplify different frequency ranges.";
leaf name {
type string;
description
"The name of the amplifier element as specified in
the vendor's specification associated with the
type-variety.";
}
container frequency-range {
description
"The frequency range amplified by the amplifier
element.";
uses l0-types:frequency-range;
}
leaf actual-gain {
type l0-types:power-in-db-or-null;
mandatory true ;
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description "..";
}
leaf tilt-target {
type l0-types:decimal-2-digits-or-null;
mandatory true ;
description
"The tilt target defined between lower and upper
frequency of the amplifier frequency range.";
}
leaf out-voa {
type l0-types:power-in-db-or-null;
units dB;
mandatory true;
description "..";
}
leaf in-voa {
type l0-types:power-in-db-or-null;
mandatory true;
description "..";
}
leaf total-output-power {
type l0-types:power-in-db-or-null;
mandatory true;
description
"It represent total output power measured in the range
specified by the frequency-range.
Optical power is especially needed to re-compute/check
consistency of span (fiber+ concentrated loss) loss
value, with respect to loss/gain information on
elements.";
}
uses power-param;
leaf raman-direction {
type enumeration {
enum co-propagating {
description
"Co-propagating indicates that optical pump light
is injected in the same direction to the optical
signal that is amplified (forward pump).";
}
enum counter-propagating {
description
"Counter-propagating indicates that optical pump
light is injected in opposite direction to the
optical signal that is amplified (backward pump).";
}
}
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description
"The direction of injection of the raman pump.";
}
list raman-pump {
description
"The list of pumps for the Raman amplifier.";
leaf frequency {
type l0-types:frequency-thz;
description
"The raman pump central frequency.";
}
leaf power {
type l0-types:decimal-2-digits-or-null;
units "Watts";
description
"The total pump power considering a depolarized pump
at the raman pump central frequency.";
}
}
} // list amplifier-element
} // container operational
} // container amplifier
} // grouping amplifier-params
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 l0-types:decimal-2-digits-or-null;
units km;
mandatory true ;
description "length of fiber";
}
leaf loss-coef {
type l0-types:decimal-2-digits-or-null;
units dB/km;
mandatory true ;
description "loss coefficient of the fiber";
}
leaf total-loss {
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type l0-types:power-in-db-or-null;
mandatory true ;
description
"includes all losses: fiber loss and conn-in and
conn-out losses";
}
leaf pmd{
type l0-types:decimal-2-digits-or-null;
units sqrt(ps);
description "pmd of the fiber";
}
leaf conn-in{
type l0-types:power-in-db-or-null;
description "connector-in";
}
leaf conn-out{
type l0-types:power-in-db-or-null;
description "connector-out";
}
}
}
grouping roadm-express-path {
description
"The optical impairments of a ROADM express path.";
leaf roadm-pmd {
type union {
type decimal64 {
fraction-digits 8;
range "0..max";
}
type empty;
}
units "ps/(km)^0.5";
description
"Polarization Mode Dispersion";
}
leaf roadm-cd {
type union {
type decimal64 {
fraction-digits 5;
}
type empty;
}
units "ps/nm";
description "Chromatic Dispersion";
}
leaf roadm-pdl {
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type l0-types:power-in-db-or-null;
description "Polarization dependent loss";
}
leaf roadm-inband-crosstalk {
type l0-types:power-in-db-or-null;
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 l0-types:power-in-db-or-null;
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 "The optical impairments of a ROADM add path.";
leaf roadm-pmd {
type union {
type decimal64 {
fraction-digits 8;
range "0..max";
}
type empty;
}
units "ps";
description
"Polarization Mode Dispersion";
}
leaf roadm-cd {
type union {
type decimal64 {
fraction-digits 5;
}
type empty;
}
units "ps/nm";
description "Cromatic Dispersion";
}
leaf roadm-pdl {
type l0-types:power-in-db-or-null;
description "Polarization dependent loss";
}
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leaf roadm-inband-crosstalk {
type l0-types:power-in-db-or-null;
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 l0-types:power-in-db-or-null;
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 l0-types:power-in-dbm-or-null;
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:snr-or-null;
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
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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 union {
type decimal64 {
fraction-digits 5;
}
type empty;
}
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";
leaf roadm-pmd {
type union {
type decimal64 {
fraction-digits 8;
range "0..max";
}
type empty;
}
units "ps/(km)^0.5";
description
"Polarization Mode Dispersion";
}
leaf roadm-cd {
type union {
type decimal64 {
fraction-digits 5;
}
type empty;
}
units "ps/nm";
description "Chromatic Dispersion";
}
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leaf roadm-pdl {
type l0-types:power-in-db-or-null;
description "Polarization dependent loss";
}
leaf roadm-inband-crosstalk {
type l0-types:power-in-db-or-null;
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 l0-types:power-in-db-or-null;
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 l0-types:power-in-db-or-null;
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 l0-types:power-in-db-or-null;
description
"The net loss from the ROADM input,
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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 l0-types:power-in-dbm-or-null;
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 l0-types:power-in-dbm-or-null;
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 l0-types:power-in-dbm-or-null;
description
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"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:snr-or-null;
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 union {
type decimal64 {
fraction-digits 5;
}
type empty;
}
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
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of the carriers to a target value";
}
}
grouping concentratedloss-params{
description "concentrated loss";
container concentratedloss{
description "concentrated loss";
leaf loss {
type l0-types:power-in-db-or-null;
mandatory true;
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 "/nw:networks/nw:network/nt:link/tet:te
/tet:te-link-attributes/OMS-attributes
/equalization-mode='carrier-power'";
leaf nominal-carrier-power{
type l0-types:power-in-dbm-or-null;
description
" Reference channel power. Same grouping is used for the
OMS power after the ROADM (input of the OMS) or after the
out-voa of each amplifier. ";
}
}
case power-spectral-density{
when "/nw:networks/nw:network/nt:link/tet:te
/tet:te-link-attributes/OMS-attributes
/equalization-mode='power-spectral-density'";
leaf nominal-power-spectral-density{
type union {
type decimal64 {
fraction-digits 16;
}
type empty;
}
units W/Hz ;
description
" Reference power spectral density after
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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:snr;
description "generalized snr";
}
leaf equalization-mode{
type identityref {
base l0-types:type-power-mode;
}
mandatory true;
description "equalization mode";
}
uses power-param;
}
grouping otsi-group {
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 uint16;
description "OTSi carrier-id";
}
leaf otsi-carrier-frequency {
type union {
type l0-types:frequency-thz;
type empty;
}
description
"OTSi carrier frequency, equivalent to the
actual configured transmitter frequency";
}
leaf-list nmc-path-id {
type uint16;
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description
"The list of the possible Network Media Channel (NMC) paths
associated with the OTSi which have different optical
impairments.
This list is meaningful in case the OTSi can be associated
with multiple NMC paths
(e.g., when OPS protection is configured).
The list can be empty when the OTSi has only one
NMC path.";
}
} // 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 otsi-group-ref {
type leafref {
path "/nw:networks/nw:network/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";
}
list otsi-ref {
description
"The list of references to the OTSis and their NMC paths
within the OTSiG carried by this media channel.";
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leaf otsi-carrier-ref {
type leafref {
path "/nw:networks/nw:network/"
+ "otsi-group[otsi-group-id=current()"
+ "/../../otsi-group-ref]/"
+ "otsi/otsi-carrier-id" ;
}
description
"Reference to the OTSi within the OTSiG carried
by this media channel.";
}
leaf-list nmc-path-ref {
type leafref {
path "/nw:networks/nw:network/"
+ "otsi-group[otsi-group-id=current()"
+ "/../../otsi-group-ref]/"
+ "otsi[otsi-carrier-id=current()"
+ "/../otsi-carrier-ref]/nmc-path-id" ;
}
description
"References to the NMC paths of this OTSi which are
routed through this media channel.";
}
}
leaf delta-power {
type l0-types:power-in-dbm-or-null;
description
" Deviation from the reference carrier power defined for
the OMS.";
}
} // 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)";
}
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leaf oms-element-uid {
type union {
type string;
type empty;
}
description
"unique id of the element if it exists";
}
container reverse-element-ref {
description
"It contains references to the elements which are
associated with this element in the reverse
direction.";
leaf link-ref {
type leafref {
path "../../../../../../../nt:link/nt:link-id";
}
description
"The reference to the OMS link which the OMS elements
belongs to.";
}
leaf-list oms-element-ref {
type leafref {
path "../../../../../../../nt:link[nt:link-id="
+ "current()/../link-ref]/tet:te/"
+ "tet:te-link-attributes/OMS-attributes/"
+ "OMS-elements/elt-index";
}
description
"The references to the OMS elements.";
}
}
choice element {
mandatory true;
description "OMS element type";
case amplifier {
uses tet:geolocation-container;
uses amplifier-params;
}
case fiber {
uses fiber-params;
}
case concentratedloss {
uses concentratedloss-params ;
}
}
}
}
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grouping otsi-ref {
description
"References to an OTSi.
This grouping is intended to be reused within the
transceiver's list only.";
leaf otsi-group-ref {
type leafref {
path "../../../../../otsi-group/otsi-group-id";
}
description
"The OTSi generated by the transceiver's transmitter.";
}
leaf otsi-ref {
type leafref {
path "../../../../../otsi-group[otsi-group-id=" +
"current()/../otsi-group-ref]/otsi/otsi-carrier-id";
}
description
"The OTSi generated by the transceiver's transmitter.";
}
}
/* 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" {
when "nw:network-types/tet:te-topology" +
"/optical-imp-topo:optical-impairment-topology" {
description
"This augment is only valid for Optical Impairment.";
}
description
"Network augmentation for optical impairments data.";
list otsi-group {
key "otsi-group-id";
config false;
description
"the list of possible OTSiG representing client digital
stream";
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leaf otsi-group-id {
type string;
description
"A network-wide unique identifier of otsi-group element.
It could be structured e.g., as an URI or as an UUID.";
}
uses otsi-group;
} // list of OTSiG
}
augment "/nw:networks/nw:network/nw:node" {
when "../nw:network-types/tet:te-topology" +
"/optical-imp-topo:optical-impairment-topology" {
description
"This augment is only valid for Optical Impairment.";
}
description
"Node augmentation for optical impairments data.";
list transponder {
key "transponder-id";
config false;
description "list of transponder";
leaf transponder-id {
type uint32;
description "transponder identifier";
}
leaf termination-type-capabilities {
type enumeration {
enum tunnel-only {
description
"The transponder can only be used in an Optical
Tunnel termination configuration.";
}
enum 3r-only {
description
"The transponder can only be used in a 3R
configuration.";
}
enum 3r-or-tunnel {
description
"The transponder can be configure to be used either
in an Optical Tunnel termination configuration or in
a 3R configuration.";
}
}
description
"Describes whether the transponder can be used in an
Optical Tunnel termination configuration or in a 3R
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configuration (or both).";
}
leaf supported-3r-mode {
when '(../termination-type-capabilities = "3r-only") or
(../termination-type-capabilities = "3r-or-tunnel")'
{
description
"Applies only when the transponder supports 3R
configuration.";
}
type enumeration {
enum unidir {
description
"Unidirectional 3R configuration.";
}
enum bidir {
description
"Bidirectional 3R configuration.";
}
}
description
"Describes the supported 3R configuration type.";
}
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:transceiver-capabilities;
leaf configured-mode {
type leafref {
path "../supported-modes/supported-mode/mode-id";
}
description
"Reference to the configured mode for transceiver
compatibility approach.";
}
uses l0-types:common-transceiver-configured-param;
container outgoing-otsi {
description
"The OTSi generated by the transceiver's transmitter.";
uses otsi-ref;
}
container incoming-otsi {
description
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"The OTSi received by the transceiver's received.";
uses otsi-ref;
}
leaf configured-termination-type {
type enumeration {
enum tunnel-termination {
description
"The transceiver is currently used in an Optical
Tunnel termination configuration.";
}
enum 3r-regeneration {
description
"The transceiver is currently used in a 3R
configuration.";
}
}
description
"Describes whether the current configuration of the
transceiver is used in an Optical Tunnel termination
configuration or in a 3R configuration.
If empty, it means that the transcevier is not used.";
}
} // end of list of transceiver
} // end list of transponder
list regen-group {
key "group-id";
config false;
description
"List of 3R groups.
Any 3R group represent a group of transponder in which an a
an electrical connectivity is either in place or could be
dynamically provided, to associated transponders used for 3R
regeneration.";
leaf group-id {
type uint32;
description
"Group identifier used an index to access elements in the
list of 3R groups.";
}
leaf regen-metric {
type uint32;
description
"The cost permits choice among different group of
transponders during path computation";
}
leaf-list transponder-ref {
type leafref {
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path "../../transponder/transponder-id";
}
description
"The list of transponder belonging to this 3R group.";
}
} // end 3R-group
}
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 ttp-transceiver {
key "transponder-ref transceiver-ref";
config false;
description
"The list of the transceivers used by the TTP.";
leaf transponder-ref {
type leafref {
path "../../../../transponder/transponder-id";
}
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description
"The reference to the transponder hosting the transceiver
of the TTP.";
}
leaf transceiver-ref {
type leafref {
path "../../../../transponder[transponder-id=current()" +
"/../transponder-ref]/transceiver/transceiver-id";
}
description
"The reference to the transceiver of the TTP.";
}
} // list of transceivers
} // 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
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"The set of optical impairments related to a ROADM path.";
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 {
list roadm-express-path {
description
"The list of optical impairments on a ROADM express
path for different frequency ranges.
Two elements in the list must not have the same range
or overlapping ranges.";
container frequency-range {
description
"The frequency range for which these optical
impairments apply.";
uses l0-types:frequency-range;
}
uses roadm-express-path;
}
}
case roadm-add-path {
list roadm-add-path {
description
"The list of optical impairments on a ROADM add
path for different frequency ranges.
Two elements in the list must not have the same range
or overlapping ranges.";
container frequency-range {
description
"The frequency range for which these optical
impairments apply.";
uses l0-types:frequency-range;
}
uses roadm-add-path;
}
}
case roadm-drop-path {
list roadm-drop-path {
description
"The list of optical impairments on a ROADM add
path for different frequency ranges.
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Two elements in the list must not have the same range
or overlapping ranges.";
container frequency-range {
description
"The frequency range for which these optical
impairments apply.";
uses l0-types:frequency-range;
}
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 ";
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}
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
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"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";
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}
} // 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";
}
list llc-transceiver {
key "ttp-transponder-ref ttp-transceiver-ref";
config false;
description
"The list of transceivers having a LLC different from the
default LLC.";
leaf ttp-transponder-ref {
type leafref {
path "../../../../ttp-transceiver/transponder-ref";
}
description
"The reference to the transponder hosting the transceiver
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of this LLCL entry.";
}
leaf ttp-transceiver-ref {
type leafref {
path "../../../../ttp-transceiver/transceiver-ref";
}
description
"The reference to the the transceiver of this LLCL entry.";
}
leaf is-allowed {
type boolean;
description
"'true' - connectivity from this transceiver is allowed;
'false' - connectivity from this transceiver is
disallowed.";
}
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>
5. Security Considerations
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.
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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).
6. IANA Considerations
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)
--------------------------------------------------------------------
7. Acknowledgments
We thank Daniele Ceccarelli and Oscar G. De Dios for useful
discussions and motivation for this work.
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
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[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/info/rfc8341>.
[RFC8795] Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
O. Gonzalez de Dios, "YANG Data Model for Traffic
Engineering (TE) Topologies", RFC 8795,
DOI 10.17487/RFC8795, August 2020,
<https://www.rfc-editor.org/info/rfc8795>.
8.2. Informative References
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC6566] Lee, Y., Ed., Bernstein, G., Ed., Li, D., and G.
Martinelli, "A Framework for the Control of Wavelength
Switched Optical Networks (WSONs) with Impairments",
RFC 6566, DOI 10.17487/RFC6566, March 2012,
<https://www.rfc-editor.org/info/rfc6566>.
[RFC7446] Lee, Y., Ed., Bernstein, G., Ed., Li, D., and W. Imajuku,
"Routing and Wavelength Assignment Information Model for
Wavelength Switched Optical Networks", RFC 7446,
DOI 10.17487/RFC7446, February 2015,
<https://www.rfc-editor.org/info/rfc7446>.
[RFC7579] Bernstein, G., Ed., Lee, Y., Ed., Li, D., Imajuku, W., and
J. Han, "General Network Element Constraint Encoding for
GMPLS-Controlled Networks", RFC 7579,
DOI 10.17487/RFC7579, June 2015,
<https://www.rfc-editor.org/info/rfc7579>.
[RFC7581] Bernstein, G., Ed., Lee, Y., Ed., Li, D., Imajuku, W., and
J. Han, "Routing and Wavelength Assignment Information
Encoding for Wavelength Switched Optical Networks",
RFC 7581, DOI 10.17487/RFC7581, June 2015,
<https://www.rfc-editor.org/info/rfc7581>.
[RFC7698] Gonzalez de Dios, O., Ed., Casellas, R., Ed., Zhang, F.,
Fu, X., Ceccarelli, D., and I. Hussain, "Framework and
Requirements for GMPLS-Based Control of Flexi-Grid Dense
Wavelength Division Multiplexing (DWDM) Networks",
RFC 7698, DOI 10.17487/RFC7698, November 2015,
<https://www.rfc-editor.org/info/rfc7698>.
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[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/info/rfc8342>.
[RFC8345] Clemm, A., Medved, J., Varga, R., Bahadur, N.,
Ananthakrishnan, H., and X. Liu, "A YANG Data Model for
Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March
2018, <https://www.rfc-editor.org/info/rfc8345>.
[RFC8453] Ceccarelli, D., Ed. and Y. Lee, Ed., "Framework for
Abstraction and Control of TE Networks (ACTN)", RFC 8453,
DOI 10.17487/RFC8453, August 2018,
<https://www.rfc-editor.org/info/rfc8453>.
[RFC9093] Zheng, H., Lee, Y., Guo, A., Lopez, V., and D. King, "A
YANG Data Model for Layer 0 Types", RFC 9093,
DOI 10.17487/RFC9093, August 2021,
<https://www.rfc-editor.org/info/rfc9093>.
[RFC9094] Zheng, H., Lee, Y., Guo, A., Lopez, V., and D. King, "A
YANG Data Model for Wavelength Switched Optical Networks
(WSONs)", RFC 9094, DOI 10.17487/RFC9094, August 2021,
<https://www.rfc-editor.org/info/rfc9094>.
[I-D.ietf-ccamp-layer0-types-ext]
Beller, D., Belotti, S., Zheng, H., Busi, I., and E. L.
Rouzic, "A YANG Data Model for Layer 0 Types - Revision
2", Work in Progress, Internet-Draft, draft-ietf-ccamp-
layer0-types-ext-00, 10 August 2021,
<https://www.ietf.org/archive/id/draft-ietf-ccamp-layer0-
types-ext-00.txt>.
[I-D.ietf-ccamp-dwdm-if-param-yang]
Galimberti, G., Kunze, R., Burk, A., Hiremagalur, D., and
G. Grammel, "A YANG model to manage the optical interface
parameters for an external transponder in a WDM network",
Work in Progress, Internet-Draft, draft-ietf-ccamp-dwdm-
if-param-yang-06, 12 July 2021,
<https://www.ietf.org/archive/id/draft-ietf-ccamp-dwdm-if-
param-yang-06.txt>.
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[I-D.ietf-teas-te-topo-and-tunnel-modeling]
Bryskin, I., Beeram, V. P., Saad, T., and X. Liu, "TE
Topology and Tunnel Modeling for Transport Networks", Work
in Progress, Internet-Draft, draft-ietf-teas-te-topo-and-
tunnel-modeling-06, 12 July 2020,
<https://www.ietf.org/archive/id/draft-ietf-teas-te-topo-
and-tunnel-modeling-06.txt>.
[G.672] "Characteristics of multi-degree reconfigurable optical
add/drop multiplexers", ITU-T Recommendation G.672,
October 2020.
[G.807] "Generic functional architecture of the optical media
network", ITU-T Recommendation G.807, February 2020.
[G.709] "Interfaces for the Optical Transport Network (OTN)",
ITU-T Recommendation G.709, June 2016.
[G.694.1] "Spectral grids for WDM applications: DWDM frequency
grid", ITU-T Recommendation G.694.1, February 2012.
[G.959.1] "Optical transport network physical layer interfaces",
ITU-T Recommendation G.959.1, February 2012.
[G.872] "Architecture of optical transport networks",
ITU-T Recommendation G.872, December 2019.
[G.698.2] "Amplified multichannel dense wavelength division
multiplexing applications with single channel optical
interfaces", ITU-T Recommendation G.698.2, November 2018.
[G.798.1] "Types and characteristics of optical transport network
equipment", ITU-T Recommendation G.798.1, January 2013.
[G.873.1] "Optical transport network: Linear protection",
ITU-T Recommendation G.873.1, October 2017.
Appendix A. Contributors
Aihua GuoHuawei Technologies
Email: aguo@futurewei.com
Jonas MartenssonRISE
Email: jonas.martensson@ri.se
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Appendix B. Additional Authors
Young LeeSamsung Electronics
Email: younglee.tx@gmail.com
Haomian ZhengHuawei Technologies
Email: zhenghaomian@huawei.com
Nicola SamboScuola Superiore Sant'Anna
Email: nicosambo@gmail.com
Giovanni MartinelliCisco
Email: giomarti@cisco.com
Jean-Luc AugeOrange
Email: jeanluc.auge@orange.com
Julien MeuricOrange
Email: julien.meuric@orange.com
Victor LopezNokia
Email: Victor.Lopez@nokia.com
Griseri EnricoNokia
Email: Enrico.Griseri@nokia.com
Gert GrammelJuniper
Email: ggrammel@juniper.net
Authors' Addresses
Dieter Beller (editor)
Nokia
Email: Dieter.Beller@nokia.com
Esther Le Rouzic
Orange
Email: esther.lerouzic@orange.com
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Sergio Belotti
Nokia
Email: Sergio.Belotti@nokia.com
G. Galimberti
Cisco
Email: ggalimbe@cisco.com
Italo Busi
Huawei Technologies
Email: Italo.Busi@huawei.com
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