Use cases, Network Scenarios and gap analysis for Packet Optical Integration (POI) with coherent plugables under ACTN Framework
draft-poidt-ccamp-actn-poi-pluggable-usecases-gaps-00
| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Oscar Gonzalez de Dios , Jean-Francois Bouquier , Julien Meuric , Gyan Mishra , Gabriele Galimberti | ||
| Last updated | 2024-03-04 | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-poidt-ccamp-actn-poi-pluggable-usecases-gaps-00
ccamp O. G. de Dios
Internet-Draft Telefonica
Intended status: Informational J. Bouquier
Expires: 5 September 2024 Vodafone
J. Meuric
Orange
G. Mishra
Verizon
G. Galimberti
Individual
4 March 2024
Use cases, Network Scenarios and gap analysis for Packet Optical
Integration (POI) with coherent plugables under ACTN Framework
draft-poidt-ccamp-actn-poi-pluggable-usecases-gaps-00
Abstract
This document provides general overarching guidelines for control and
management of packet over optical converged networks with coherent
pluggables and focuses on operators' use cases and network scenarios.
It provides a set of use cases which are needed for the control and
management of the packet over optical networks which comprise devices
with mixes of packet and optical functions where the optical
functions may be provided on coherent pluggables. The document
provides a gap analysis to solve the use cases.
Discussion Venues
This note is to be removed before publishing as an RFC.
Discussion of this document takes place on the Common Control and
Measurement Plane Working Group mailing list (ccamp@ietf.org), which
is archived at https://mailarchive.ietf.org/arch/browse/ccamp/.
Source for this draft and an issue tracker can be found at
https://github.com/oscargdd/draft-poidt-ccamp-actn-poi-pluggable-
usecases-gaps.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
de Dios, et al. Expires 5 September 2024 [Page 1]
Internet-Draft POI coherent pluggables March 2024
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 5 September 2024.
Copyright Notice
Copyright (c) 2024 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
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Packet over Optical Converged Network Context . . . . . . . . 5
3.1. Traditional Architecture Deployment Model . . . . . . . . 5
3.2. Deployment Model with Coherent Pluggables . . . . . . . . 6
4. Network Scenarios . . . . . . . . . . . . . . . . . . . . . . 8
4.1. Scenario A - High capacity point to point connection over
dedicated direct fiber . . . . . . . . . . . . . . . . . 8
4.2. Scenario B - High capacity point to point over shared
fiber . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.3. Scenario C - High capacity point to point over
metro-regional shared meshed network . . . . . . . . . . 10
4.4. Sceanrio D - High capacity point to point optical
connection between plug and xPonder . . . . . . . . . . . 11
4.5. Other Network scenarios. . . . . . . . . . . . . . . . . 12
5. Operators' Use cases . . . . . . . . . . . . . . . . . . . . 12
5.1. End-to-end multi-layer visibility and management (valid for
both) . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.1.1. End-to-end multi-layer network and service topology
discovery and inventory . . . . . . . . . . . . . . . 12
de Dios, et al. Expires 5 September 2024 [Page 2]
Internet-Draft POI coherent pluggables March 2024
5.1.2. End-to-end multi-layer event/fault management (valid
for both) . . . . . . . . . . . . . . . . . . . . . . 14
5.1.3. End-to-end multi-layer performance management (valid
for both) . . . . . . . . . . . . . . . . . . . . . . 14
5.2. Inter-domain link validation (valid for coherent
pluggable) . . . . . . . . . . . . . . . . . . . . . . . 15
5.3. End-to-end L3VPN/L2VPN service multi-layer fulfilment with
SLA constraints (TE constraints) (valid for both) . . . . 15
5.4. Pluggable to pluggable service Provisioning . . . . . . . 15
5.5. 4. End-to-end L3VPN/L2VPN service multi-layer provisioning
with SLA constraints (TE constraints) (valid for both) . 16
5.6. End-to-end L3VPN/L2VPN service multi-layer with SLA
constraints (TE constraints) with optical restoration support
(valid for both but here focusing on the coherent
pluggable) . . . . . . . . . . . . . . . . . . . . . . . 17
6. Security Considerations . . . . . . . . . . . . . . . . . . . 17
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
8.1. Normative References . . . . . . . . . . . . . . . . . . 17
8.2. Informative References . . . . . . . . . . . . . . . . . 17
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 18
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19
1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT"
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in the
document are to be interpreted as described in [RFC2119].
The following terms abbreviations are used in this document:
* Coherent plug/pluggable: A small form factor coherent optical
module
* O-PNC: The control functions specializing in management/control of
optical and photonic functions (virtual or physical). See
[actn-rfc]
* P-PNC: The control functions specializing in management/control of
packet functions (virtual or physical). See [actn-rfc]
* xPonder: Short for Transponder and/or Muxponder
de Dios, et al. Expires 5 September 2024 [Page 3]
Internet-Draft POI coherent pluggables March 2024
2. Introduction
Packet traffic has been transferred over optical networks for many
years blending the benefits of optical transmission and switching
with packet switching. Optical systems have been separated from
packet systems, both of which have had specific dedicated devices.
In many existing network deployments, the packet and the optical
networks are engineered, operated and controlled independently. The
operation of these packet and optical networks is often siloed which
results in non-optimal and inefficient networking. Both packet and
optical systems have had relatively independent evolution. Optical
systems have been developed with increasing capacity especially with
the emergence of coherent optical techniques.
Optical component design has continued to improve density to the
point where a whole coherent optical terminal system that use to
require many circuit packs can now fit onto a single small form
factor "coherent plug". Placing coherent plugs in a device with
packet functions can reduce network cost, power consumption and
footprint as well as improve data transfer rates, reduce latency and
expand capacity (note that in some cases, other engineering and
deployment considerations still lead to separate packet and optical
solutions).
Optical transmission/switching is analogue and requires complex and
holistic control. Consequently, coordination of control of the
coherent plugs (in a device with packet functions) with the control
of the rest of the optical network is highly desirable as this best
enables robust network functionality and simplifies network
operations.
The combination of these above trends along with the desire to select
best in breed components has led to the emergence of open optical
plugs that offer a standard bus for traffic and that use CMIS
[OIF-CMIS], extended with Coherent CMIS, between coherent pluggables
and host device. These plugs are such that a plug from vendor X can
be installed in vendor Y's device with packet functions etc.
An architecture analysis has been carried out by the MANTRA sub-group
in the OOPT / TIP group (Open Optical & Packet Transport / Telecom
Infra Project)
[MANTRA-whitepaper-IPoWDM-convergent-SDN-architecture].
This document provides guidellines for control and management of
packet over optical converged networks and it is divided into
following sections:
* Section 3 Packet over optical converged network context
de Dios, et al. Expires 5 September 2024 [Page 4]
Internet-Draft POI coherent pluggables March 2024
* Section 4 Network Scenarios
* Section 5 Use cases for the control and management of Packet over
Optical Converged Networks
* Section 5 Gap analysis
3. Packet over Optical Converged Network Context
A packet over optical network represents an efficient paradigm that
harnesses the power of both packet-switching and optical
technologies. In this approach, the overlay IP or MPLS packets are
transmitted through an underlying optical network. The fusion of
packet and optical networks offer a host of advantages, including
accelerated data transfer rates, diminished latency, and expanded
network capacity.
In general, two deployment models can be used to deploy the packet
over optical networks:
* Traditional architecture deployment model
* Deployment model with coherent pluggables
3.1. Traditional Architecture Deployment Model
The traditional architecture involves separation of the packet
network from the optical network as shown in Figure 1. In
traditional approach, the packet layer responsible for routing and
forwarding is decoupled from the underlying optical transport layer.
This approach offers several benefits, including the ability to scale
each layer independently, optimize resource utilization, and simplify
network management through centralized software control.
Disaggregation enables network operators to choose best-of-breed
components for each layer, fostering innovation and competition in
the networking industry. However, implementing and managing a
disaggregated network also comes with challenges related to
interoperability, integration, and maintaining end-to-end performance
across the various layers.
de Dios, et al. Expires 5 September 2024 [Page 5]
Internet-Draft POI coherent pluggables March 2024
|----------| |----------|
| Packet | IP Link | Packet |
| Device |===================================| Device |
| 1 |\ /| 2 |
|----------| \ Grey / |----------|
\ Optics /
| |
............ | ......................... | ............
. | | .
. |---------| |-----------| |---------| .
. | xPonder |-----| Photonics |-----| xPonder | .
. |---------| |-----------| |---------| .
.......................................................
Optical Network = Photonics + xPonder
Legend:
==== IP Link
---- Optical fibers
++++ Coherent pluggables
xPonder: Muxponder or transponder
Photonics: ROADM + Amp + Regen
Figure 1: Packet over Optics Traditional Architecture Deployment
Model
3.2. Deployment Model with Coherent Pluggables
The second approach is to take advantage of the small implementation
footprint of the xPonder functions and to deploy these functions on a
single small form factor plug (aka Coherent pluggables) and then
place plugs directly into the packet devices as shown in Figure 2(A).
Placing this small form factor pluggable in a device with packet
functions can reduce network cost, power consumption and footprint
(when these benefits are not outweighed by other engineering
considerations). Depending on the application, distance between
packet devices, quality of fibers and so on it might be that there is
no need for a ROADM network, i.e., direct connectivity between packet
devices via plugs is possible.
By incorporating coherent plugs into routers, network operators can
achieve higher data rates, greater spectral efficiency, and improved
tolerance to optical impairments. This is especially valuable in
scenarios where traditional electronic signaling might encounter
limitations. Coherent plugs enable routers to leverage advanced
modulation schemes, digital signal processing, and error correction
techniques, enhancing their ability to handle complex optical
signals.
de Dios, et al. Expires 5 September 2024 [Page 6]
Internet-Draft POI coherent pluggables March 2024
One of the key advantages of using coherent plugs in routers is the
potential to bridge the gap between long-haul and metro networks,
providing a seamless and efficient transition of data across various
network segments. This technology can contribute to the evolution of
high-speed data centers, interconnection between data centers, and
the overall growth of data-intensive applications.
as noted above, for some use-cases when the distance between packet
devices is short and optical power of pluggables are enough, the
photonics devices might not be needed as shown in Figure 2(B).
|-----------| |-----------|
| Packet | IP Link | Packet |
| Device +++++ ======================= +++++ Device |
| 1 |\ /| 2 |
|-----------| \ / |-----------|
\ DWDM Optics /
| |
| |-----------| |
|-----| Photonics |-----|
|-----------|
(A)
|-----------| |-----------|
| Packet | IP Link | Packet |
| Device +++++ ======================= +++++ Device |
| 1 |\ /| 2 |
|-----------| \ / |-----------|
| |
|-------------------------|
(B)
Legend:
==== IP Link
---- Optical fibers
++++ Coherent pluggables
xPonder: Muxponder or transponder
Photonics: ROADM + Amp + Regen
Optical Network: Photonics + pluggables
Figure 2: Packet over Optics Deployment Model with Coherent Plugs
In reality, the operators' packet over optical networks will most
likely be a combination of networks shown in Figure 1 and Figure 2
where the optical network contains both coherent pluggables and
xPonders as shown in Figure 3.
de Dios, et al. Expires 5 September 2024 [Page 7]
Internet-Draft POI coherent pluggables March 2024
|-----------| |-----------|
| Packet | IP Link | Packet |
| Device +++++ =========================== +++++ Device |
| 1 |\ /| 2 |
|-----------| \ / |-----------|
\----------| |------------/
| |
|---------| |-----------| |---------|
| | | | | |
| xPonder |-----| Photonics |------| xPonder |
| | | | | |
|---------| |-----------| |---------|
| |
| |
|----------| / \ |----------|
| Packet |/ IP Link \| Packet |
| Device |====================================| Device |
| 3 | | 4 |
|----------| |----------|
Optical Network: Photonics + pluggables + xPonder
Legend:
==== IP Link
---- Optical fibers
++++ Coherent pluggables
xPonder: Muxponder or transponder
Photonics: ROADM + Amp + Regen
Figure 3: Packet over Optics Deployment Model with Coherent Plugs
and xPonders
4. Network Scenarios
This section provides a set of packet over optical network scenarios,
starting with the most common ones.
4.1. Scenario A - High capacity point to point connection over
dedicated direct fiber
As depicted in Figure 4, this scenario considers a point-to-point
optical service over a short distance (e.g., up to 100 km) using
dedicated fiber.
Note that there is no amplification and no protection in this
scenario.
de Dios, et al. Expires 5 September 2024 [Page 8]
Internet-Draft POI coherent pluggables March 2024
Packet Packet
Device A Device B
+----+ IP Link (between Router Ports) +----+
| |.............................................................| |
| | | |
| | Optical Service (Plug-to-Plug) | |
| | ..................................................... | |
| |------| |------| |
| | | | | |
| |Plug A|===================================================|Plug B| |
| | | | | |
| |------| |------| |
| | | |
+----+ +----+
Figure 4: Network topology with dedicated direct fiber
4.2. Scenario B - High capacity point to point over shared fiber
This scenario extends Figure 4 by making more efficient use of the
deployed fiber infrastructure.
As shown in Figure 5, this scenario considers a point-to-point
optical service over a short distance (e.g., up to 100 km) using a
physical optical network with DWDM filters and amplifiers. Several
point-to-point connections can be multiplexed from the same packet
devices.
Note that there is no protection in this scenario.
de Dios, et al. Expires 5 September 2024 [Page 9]
Internet-Draft POI coherent pluggables March 2024
Packet Packet
Device A Device B
+----+ IP Link (between Router Ports) +----+
| |.............................................................| |
| | | |
| | Optical Service (Plug-to-Plug) | |
| | ..................................................... | |
| |------| |------| |
| | | |-------| |-------| |-------| | | |
| |Plug A|======| Filter|======| AMP |======| Filter|======|Plug B| |
| | | ||==| | | | | |==|| | | |
| |------| || |-------| |-------| |-------| || |------| |
| | || || | |
+----+ || || +----+
|| ||
|------| || || |------|
| |==|| ||==| |
|Plug C| |Plug D|
| | | |
|------| |------|
Figure 5: Network topology with shared direct fiber network
4.3. Scenario C - High capacity point to point over metro-regional
shared meshed network
This scenario extends Figure 5 by making more flexible use of the
fiber network infrastructure.
As shown in Figure 6, this scenario considers a point-to-point
optical service over a metro/regional network (e.g., up to 500 km).
The metro/regional network contains DWDM filters, amplifiers and
optical switching.
Note that there is no resilience in this scenario. (CHECK AS
RESTORATION COULD BE A CHOICE)
de Dios, et al. Expires 5 September 2024 [Page 10]
Internet-Draft POI coherent pluggables March 2024
Packet Packet
Device A Device B
+----+ IP Link (between Router Ports) +----+
| |.............................................................| |
| | | |
| | Optical Service (Plug-to-Plug) | |
| | ..................................................... | |
| |------| |------| |
| | | |-------| |-------| |-------| | | |
| |Plug A|======| ROADM |======| ROADM |======| ROADM |======|Plug B| |
| | | | + Amp | | | | + Amp | | | |
| |------| |-------| |-------| |-------| |------| |
| | | |
+----+ +----+
Figure 6: Network topology with shared switched fiber network
4.4. Sceanrio D - High capacity point to point optical connection
between plug and xPonder
This scenario, shown in Figure 7 and extends network topologies
Figure 4 to Figure 6 and covers a corner case, where one end of an
optical service is terminated on a plug and the other end is
terminated on a traditional xPonder (transponder or muxponder) with
grey optics to a packet device. This scenario is encountered when
one of the packet device does not support coherent plugables.
Packet Packet
Device A Device B
+----+ IP Link (between Router Ports) +----+
| |.............................................................| |
| | | |
| | Optical Service (Plug-to-xPonder) |-------| | |
| | ...................................| | | |
| |------| | | | |
| | | |-----------------------| | | Grey Optics | |
| |Plug A|====| Photonics |=====|xPonder|=============| |
| | | |-----------------------| | | | |
| |------| |-------| | |
| | | |
+----+ +----+
Figure 7: Network topology with symmetric plug and transponder
de Dios, et al. Expires 5 September 2024 [Page 11]
Internet-Draft POI coherent pluggables March 2024
4.5. Other Network scenarios.
* Network topology with shared switched fiber network with
regenerators: This is extension of scenario C Figure 6 when the
photonic network has regenerators.
* Asymmetric interconnect Network topology where the protection open
at one end but both protection legs are terminated on separate
xPonder or coherent pluggables.
* IP Lag Network topology where the IP link between two packet
devices are provided by multiple coherent plugs.
* Practical network deployments which includes the mix of many
network topologies explained above.
5. Operators' Use cases
This section provides a set of packet over optical general use cases
which are applicable to any network topologies in Section 4 and both
for multi-layer networks using or not coherent pluggables in the
routers. These use cases are presented following current operators’
priorities order.
The use cases a generally applicable for both the traditional packet
over optical integration based on grey interfaces in the IP routers
and use of transponders/muxponders in the optical domain and for the
packet over optical integration considering coherent DWDM pluggables
in the IP routers over a media channel/Network Media channel in the
optical domain. For clarification purposes, the mention ‘valid for
both’ has been added in the name of each use case else ‘valid for
coherent pluggable’ when the use case is specific to the coherent
pluggable approach.
5.1. End-to-end multi-layer visibility and management (valid for both)
5.1.1. End-to-end multi-layer network and service topology discovery
and inventory
The objective of the use case is to have a full end-to-end multi-
layer view from all the layers and their inter-dependencies: service
layer (e.g. L3VPN/L2VPN), transport layer (RSVP-TE, SR-TE), IP layer
(IGP), Ethernet layer, OTN L1 layer (optional), photonic L0 layer
(OCh, OMS, OTS and fibre). The discovery process, in addition to the
layered logical view, includes the inventory discovery by each
controller and exposure to the MDSC of the required information for a
complete end-to-end multi-layer view of the network.
de Dios, et al. Expires 5 September 2024 [Page 12]
Internet-Draft POI coherent pluggables March 2024
5.1.1.1. Coherent DWDM pluggable insertion in the router linecard port
('valid for coherent pluggable')
Once a pluggable module is inserted in the proper linecard port, the
host device must recognise the hardware component (ZR+ pluggable
module) and expose its attributes and capabilities to the controller.
For example, ZR+ modules can share the operational-mode that
summarize the most important pluggable characteristics (such as FEC
type, modulation format, baud rate, bit rate, etc.). If the hardware
component has been successfully recognised, the host device is then
ready to create and expose the necessary logical arrangements.
5.1.1.2. Inventory of Coherent DWDM pluggable ('valid for coherent
pluggable').
The domain controller exposes to the MDSC hardware inventory
information of the devices under its supervision. For full router
inventory (linecards, ports, etc.) see draft-ietf-ivy-network-
inventory-yang. In addition, it has to include the coherent
pluggable transceiver capabilities. These include, for instance,
operational-modes supported (ITU-T application codes, organizational
modes), min/max central-frequency range supported, min/max output
power supported, min/max received power supported etc. In case of
discovery of any HW mismatch between coherent DWDM pluggable and
router linecard port capabilities the controller shall report HW
mismatch alarm to MDSC. An example is a linecard multi-rate port vs
coherent DWDM pluggable with only one client/line rate (e.g.
1x400GE).
5.1.1.3. Coherent pluggable OTSi service discovery information ('valid
for coherent pluggable').
Once a router-to-router connection with coherent pluggables has been
created over a Network Media Channel in the optical Line system, then
it is required to expose the OTSi service. The relevant OTSi
information could be nominal-central-frequency, tx-output-power,
operational-mode-ID, operational-status, admin-status etc.
5.1.1.4. Discovery of layer relationships
In case the operational mode has already been configured, the host
device and the controlller need to create the nececessary
arrangements to navigate from the interface where the router traffic
is injected up the port connecting to the fiber. That is, the layer
hierarchy from L0 to L3 needs to be completed and exposed.
de Dios, et al. Expires 5 September 2024 [Page 13]
Internet-Draft POI coherent pluggables March 2024
5.1.2. End-to-end multi-layer event/fault management (valid for both)
The Target is this use case is to have a full end-to-end multi-layer
correlation of events at different layers and domains (e.g.
operational-status changes reported at OTS/OMS/OCh/ODUk (optional),
IP link level, LSP level, L3VPN/L2VPN level etc.) so that final root
cause can be quickly identified and fixed (e.g. fibre cut vs coherent
DWDM pluggable failure). This use case is divided in two: *
Correlation of ZR+ connection (OTSi service) operational-status with
MC/NMC operational-status (‘valid for coherent pluggable) In this
case, the target is to expose to the MDSC both the events/faults from
the ZR+ connection (OTSi service) and ZR+ pluggables as well as for
the MC/NMC associated to this ZR+ connection (OTSi service) in the
DWDM Line system so that proper correlation can be performed at MDSC
level * Correlation of coherent pluggable operational status, port
status, Ethernet link operational status, IP link status
5.1.3. End-to-end multi-layer performance management (valid for both)
In this use case, the goal is to have the possibility to analyse
through performance monitoring of the different layers mentioned
above and be able, in case of end-to-end L2VPN/L3VPN service
degradation, to identify the root cause of the degradation. For
scaling purposes, the target should be, upon service fulfilment
phase, to set up the right TCAs associated to each layer that can
allow to meet the L2VPN/L3VPN service SLA (e.g. in terms of latency,
jitter, BW, etc.). This use case is divided in two:
5.1.3.1. Performance management of the ZR+ connection (OTSi service)
(‘valid for coherent pluggable)
Target is to have the basic performance parameters of each OTSi
service running between two pluggables exposed towards the MDSC.
Best for operators could be to defined TCA (Threshold crossing
alerts) from MDSC for each OTSI service and be notified only when the
Thresholds defined are not met? Operator shall be able to decide
which parameters and for which OTSi service. But all the parameters
shall be visible if needed by operators.
Note: Router shall provide also all the possible performance counters
not only for OTSi service/Ethernet service etc. but also for the
pluggable itself
As an example operators should have the ability to get visibility on
pre-FEC-BER for a given OTSi service and see the trend before post-
FEC-BER is affected
de Dios, et al. Expires 5 September 2024 [Page 14]
Internet-Draft POI coherent pluggables March 2024
5.1.3.2. Performance management of the Ethernet link running over the
OTSi service and also of the IP link running over this
Ethernet link.
TBC
5.2. Inter-domain link validation (valid for coherent pluggable)
Documenting the patch cord that connects the port of the coherent
DWDM pluggable in the routers to the optical node (e.g. to the right
Add/Drop port of the ROADM) is performed. This manual operation is
prone to human mistakes. It would be highly beneficial for operators
to have a mean to check/discover that the right pluggable has been
connected to the desired ROADM port. This use case requires the
ability to expose to the MDSC the power levels at coherent DWDM
pluggable side and at ROADM port side to perform the right
correlation and validation.
5.3. End-to-end L3VPN/L2VPN service multi-layer fulfilment with SLA
constraints (TE constraints) (valid for both)
This use case is described in [draft-ietf-teas-actn-poi-
applicability] for the SR-TE case which is relevant as target use
case for operators. If new connectivity is required between the
routers and at optical level then full automation could be achieved.
However considering PMO (Present Mode of Operation) in most
operators, before an optical path is setup either between two native
transponders or between two coherent pluggables in routers, a
detailed optical planning and validation is always required. So, the
automation of this use case is considered more for future mode of
operations (FMO) and has not the same priority as the previous two
use cases.
5.4. Pluggable to pluggable service Provisioning
The following specific coherent DWDM pluggable provisioning sub-cases
are identified: ### Manual Day 1 configuration (‘valid for coherent
pluggable) Knowing the coherent pluggable characteristics
(performance and optical impairments for a specific operational-mode-
ID), the optical planning and validation process is performed and the
following parameters are communicated by optical team to IP team:
nominal-central-frequency, tx-output-power, operational-mode-ID so
that the coherent pluggables at both ends in the routers can be
correctly configured in a manual way (e.g. through P-PNC or any other
mean). As prerequisite before the coherent pluggable configuration,
the optical team has properly configured the Media Channel in the
line system DWDM network through the O-PNC. ### Semi-manual Day 1
configuration (‘valid for coherent pluggable’) Same optical planning
de Dios, et al. Expires 5 September 2024 [Page 15]
Internet-Draft POI coherent pluggables March 2024
and validation is performed first by optical team and then parameters
are provided to MDSC operations engineer so that they can be set-up
at Hierarchical SDN controller level and provisioned by P-PNC in the
corresponding router’s pluggables. ### Semi-Automated Day 1
configuration with Path Computation API request from MDSC towards PNC
(‘valid for coherent pluggable’) In this use case the start of the
pluggable to pluggable connectivity is triggered by the connectivity
needs of a packet service (slice, vpn, etc...). In the context of
ACTC, the process would start with MDSC receiving the service request
(e.g. L3VPN) (or service provisioning from a GUI) but a new optical
connectivity is needed between two ZR/ZR+ pluggables which are
already physically connected (patch cord) to ROADM nodes ports. MDSC
sends a path computation request to the O-PNC asking for a specific
MC/NMC between source Mux/Dmux and destination Mux/Dmux for a target
bitrate (e.g. 400G) and O-PNC in coordination with planning tool
calculates the optical path (after successful PCE computation) for
this given bitrate (e.g. 400G) with a specific operational-mode-ID
supported by these coherent pluggables. It validates the optical
path defining the central-frequency, output-power, operational-mode-
ID to be configured in the coherent pluggables. O-PNC updates the
MDSC of successful optical path creation exposing this new optical
path to the MDSC along with the nominal-central-frequency, the
target-output-power, the operational-mode-ID for which this MC/NMC
was created, etc. The optical path is provisioned but operational-
status is disabled. The MDSC requests the relevant PNC to configure
both source and target pluggables with the calculated parameters.
MDSC uses the coherent pluggable CRUD data model to be used on MPI to
configure the corresponding ZR+ connection (OTSi service) in the
source and destination coherent pluggables. This operation is
supported by the PNC which will be in charge also to turn-on the
laser and complete the optical path set-up. At this point the
optical path will be moved to operational state and the Packet
traffic starts to flow. ### Fully automated Day 1 configuration (For
future discussions)
5.5. 4. End-to-end L3VPN/L2VPN service multi-layer provisioning with
SLA constraints (TE constraints) (valid for both)
This use case is described in
[I-D.draft-ietf-teas-actn-poi-applicability] for the SR-TE case which
is relevant as target use case for operators. If new connectivity is
required between the routers and at optical level then full
automation could be achieved. However considering PMO (Present Mode
of Operation) in most operators, before an optical path is setup
either between two native transponders or between two coherent
pluggables in routers, a detailed optical planning and validation is
always required. So, the automation of this use case is considered
more for future mode of operations (FMO) and has not the same
de Dios, et al. Expires 5 September 2024 [Page 16]
Internet-Draft POI coherent pluggables March 2024
priority as the previous two use cases.
5.6. End-to-end L3VPN/L2VPN service multi-layer with SLA constraints
(TE constraints) with optical restoration support (valid for both
but here focusing on the coherent pluggable)
This use case has not the same priority as the previous ones as
protection in multi-layer Core/Backhaul networks is usually
implemented at IP layer (e.g. FRR with RSVP-TE, TI-LFA with SR and
SR policies in SR-TE) to avoid proven protection races. a. ZR+ links
over DWDM network can be considered out of the L0 control plane so
that no restoration is applied to those links b. ZR+ links over DWDM
network can be considered part of the L0 control plane but no
restoration is enabled for those links c. ZR+ links over DWDM
network can be considered as part of the L0 control plane with
restoration enabled for those links but nominal-central-frequeny is
maintained unchanged after L0 restoration. Only output-power could
be tuned for the new restored path determined by the L0 control plane
d. ZR+ links over DWDM network can be considered as part of the L0
control plane with restoration enabled for those links and nominal-
central-frequency and output power need to be tuned for the new
restored path determined by the L0 control plane.
6. Security Considerations
TBD
7. IANA Considerations
This document has no IANA actions.
8. References
8.1. Normative References
[OIF-CMIS] "OIF Implementation Agreement (IA) Common Management
Interface Specification (CMIS))", 27 April 2022,
<https://www.oiforum.com/wp-content/uploads/OIF-CMIS-
05.2.pdf>.
[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/rfc/rfc2119>.
8.2. Informative References
de Dios, et al. Expires 5 September 2024 [Page 17]
Internet-Draft POI coherent pluggables March 2024
[actn-rfc] "Framework for Abstraction and Control of TE Networks
ACTN", 19 December 2018,
<https://datatracker.ietf.org/doc/rfc8453/>.
[MANTRA-whitepaper-IPoWDM-convergent-SDN-architecture]
"IPoWDM convergent SDN architecture - Motivation,
technical definition & challenges", 31 August 2022,
<https://telecominfraproject.com/wp-content/uploads/
TIP_OOPT_MANTRA_IP_over_DWDM_Whitepaper-Final-
Version3.pdf>.
[I-D.draft-ietf-teas-actn-poi-applicability]
Peruzzini, F., Bouquier, J., Busi, I., King, D., and D.
Ceccarelli, "Applicability of Abstraction and Control of
Traffic Engineered Networks (ACTN) to Packet Optical
Integration (POI)", Work in Progress, Internet-Draft,
draft-ietf-teas-actn-poi-applicability-11, 22 February
2024, <https://datatracker.ietf.org/doc/html/draft-ietf-
teas-actn-poi-applicability-11>.
Appendix A. Acknowledgments
This document has been made with consensus and contributions coming
from multiple drafts with different visions. We would like to thank
all the participants in the IETF meeting discussions.
Contributors
Nigel Davis
Ciena
Email: ndavis@ciena.com
Reza Rokui
Ciena
Email: rrokui@ciena.com
Edward Echeverry
Telefonica
Email: edward.echeverry@telefonica.com
Aihua Guo
Futurewei Technologies
Email: aihuaguo.ietf@gmail.com
de Dios, et al. Expires 5 September 2024 [Page 18]
Internet-Draft POI coherent pluggables March 2024
Brent Foster
Cisco
Research Triangle Park
North Carolina,
United States
Email: brfoster@cisco.com
Daniele Ceccarelli
Cisco
Email: daniele.ietf@gmail.com
Italo Busi
Huawei Technologies
Email: italo.busi@huawei.com
Ori Gerstel
Cisco
AMOT ATRIUM Tower 19th floor
TEL AVIV-YAFO, TA
Israel
Email: ogerstel@cisco.com
Authors' Addresses
Oscar Gonzalez de Dios
Telefonica
Email: oscar.gonzalezdedios@telefonica.com
Jean-Francois Bouquier
Vodafone
Email: jeff.bouquier@vodafone.com
Julien Meuric
Orange
Email: julien.meuric@orange.com
Gyan Mishra
Verizon
Email: gyan.s.mishra@verizon.com
de Dios, et al. Expires 5 September 2024 [Page 19]
Internet-Draft POI coherent pluggables March 2024
Gabriele Galimberti
Individual
Email: ggalimbe56@gmail.com
de Dios, et al. Expires 5 September 2024 [Page 20]