TEAS Working Group Fabio Peruzzini
Internet Draft TIM
Intended status: Informational Jean-Francois Bouquier
Vodafone
Italo Busi
Huawei
Daniel King
Old Dog Consulting
Daniele Ceccarelli
Ericsson
Expires: December 2020 June 29, 2020
Applicability of Abstraction and Control of Traffic Engineered
Networks (ACTN) to Packet Optical Integration (POI)
draft-peru-teas-actn-poi-applicability-05
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Abstract
This document considers the applicability of the IETF Abstraction
and Control of Traffic Engineered Networks (ACTN) to Packet Optical
Integration (POI), and IP and Optical DWDM domain internetworking.
In this document, we highlight the IETF protocols and YANG data
models that may be used for the ACTN and control of POI networks,
with particular focus on the interfaces between the MDSC (Multi-
Domain Service Coordinator) and the underlying Packet and Optical
Domain Controllers (P-PNC and O-PNC) to support POI use cases.
Table of Contents
1. Introduction...................................................3
2. Reference Scenario.............................................5
2.1. Generic Assumptions.......................................6
3. Multi-Layer Topology Coordination..............................7
3.1. Discovery of existing Och, ODU, IP links, IP tunnels and IP
services.......................................................7
3.1.1. Common YANG Models used at the MPI...................8
3.1.1.1. YANG models used at the Optical MPIs............8
3.1.1.2. Required YANG models at the Packet MPIs.........9
3.1.2. Inter-domain link Discovery..........................9
3.2. Provisioning of an IP Link/LAG over DWDM.................10
3.2.1. YANG models used at the MPIs........................10
3.2.1.1. YANG models used at the Optical MPIs...........10
3.2.1.2. Required YANG models at the Packet MPIs........11
3.2.2. IP Link Setup Procedure.............................12
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3.3. Provisioning of an IP link/LAG over DWDM with path
constraints...................................................12
3.3.1. YANG models used at the MPIs........................13
3.4. Provisioning Link Members to an existing LAG.............13
3.4.1. YANG Models used at the MPIs........................13
4. Multi-Layer Recovery Coordination.............................13
4.1. Ensuring Network Resiliency during Maintenance Events....13
4.2. Router Port Failure......................................13
5. Service Coordination for Multi-Layer network..................14
5.1. L2/L3VPN/VN Service Request by the Customer..............17
5.2. Service and Network Orchestration........................19
5.3. IP/MPLS Domain Controller and NE Functions...............23
5.3.1. Scenario A: Shared Tunnel Selection.................23
5.3.1.1. Domain Tunnel Selection........................24
5.3.1.2. VPN/VRF Provisioning for L3VPN.................25
5.3.1.3. VSI Provisioning for L2VPN.....................26
5.3.1.4. Inter-domain Links Update......................26
5.3.1.5. End-to-end Tunnel Management...................26
5.3.2. Scenario B: Isolated VN/Tunnel Establishment........27
5.4. Optical Domain Controller and NE Functions...............27
5.5. Orchestrator-Controllers-NEs Communication Protocol Flows29
6. Security Considerations.......................................31
7. Operational Considerations....................................31
8. IANA Considerations...........................................31
9. References....................................................31
9.1. Normative References.....................................31
9.2. Informative References...................................32
Acknowledgments..................................................34
Contributors.....................................................34
Authors' Addresses...............................................35
1. Introduction
Packet Optical Integration (POI) is an advanced use case of traffic
engineering. In wide-area networks, a packet network based on the
Internet Protocol (IP) and possibly Multiprotocol Label Switching
(MPLS) is typically deployed on top of an optical transport network
that uses Dense Wavelength Division Multiplexing (DWDM). In many
existing network deployments, the packet and the optical networks
are engineered and operated independently of each other. There are
technical differences between the technologies (e.g., routers versus
optical switches) and the corresponding network engineering and
planning methods (e.g., inter-domain peering optimization in IP vs.
dealing with physical impairments in DWDM, or very different time
scales). In addition, customers and customer needs vary between a
packet and an optical network, and it is not uncommon to use
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different vendors in both domains. Last but not least, state-of-the-
art packet and optical networks use sophisticated but complex
technologies, and for a network engineer, it may not be trivial to
be a full expert in both areas. As a result, packet and optical
networks are often managed by different technical and organizational
silos.
This separation is inefficient for many reasons. Both capital
expenditure (CAPEX) and operational expenditure (OPEX) could be
significantly reduced by better integrating the packet and the
optical network. Multi-layer online topology insight can speed up
troubleshooting (e.g., alarm correlation) and network operation
(e.g., coordination of maintenance events), multi-layer offline
topology inventory can improve service quality (e.g., detection of
diversity constraint violations) and multi-layer traffic engineering
can use the available network capacity more efficiently (e.g.,
coordination of restoration). In addition, provisioning workflows
can be simplified or automated as needed across layers (e.g, to
achieve bandwidth on demand, or to perform maintenance events).
Fully leveraging these benefits requires integration between the
management and control of the packet and the optical network. The
Abstraction and Control of TE Networks (ACTN) framework outlines the
functional components and interfaces between a Multi-Domain Service
Coordinator (MDSC) and Provisioning Network Controllers (PNCs) that
can be used for coordinating the packet and optical layers.
In this document, critical use cases for Packet Optical Integration
(POI) are described. We outline how and what is required for the
packet and the optical layer to interact to set up and operate
services. The IP networks are operated as a client of optical
networks. The use cases are ordered by increasing the level of
integration and complexity. For each multi-layer use case, the
document analyzes how to use the interfaces and data models of the
ACTN architecture.
The document also captures the current issues with ACTN and POI
deployment. By understanding the level of standardization and
potential gaps, it will help to better assess the feasibility of
integration between IP and optical DWDM domain, in an end-to-end
multi-vendor network.
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2. Reference Scenario
This document uses "Reference Scenario 1" with multiple Optical
domains and multiple Packet domains. The following Figure 1 shows
this scenario in case of two Optical domains and two Packet domains:
+----------+
| MDSC |
+-----+----+
|
+-----------+-----+------+-----------+
| | | |
+----+----+ +----+----+ +----+----+ +----+----+
| P-PNC 1 | | O-PNC 1 | | O-PNC 2 | | P-PNC 2 |
+----+----+ +----+----+ +----+----+ +----+----+
| | | |
| \ / |
+-------------------+ \ / +-------------------+
CE / PE ASBR \ | / / ASBR PE \ CE
o--/---o o---\-|-------|--/---o o---\--o
\ : : / | | \ : : /
\ : AS Domain 1 : / | | \ : AS Domain 2 : /
+-:---------------:-+ | | +-:---------------:--+
: : | | : :
: : | | : :
+-:---------------:------+ +-------:---------------:--+
/ : : \ / : : \
/ o...............o \ / o...............o \
\ Optical Domain 1 / \ Optical Domain 2 /
\ / \ /
+------------------------+ +--------------------------+
Figure 1 - Reference Scenario 1
The ACTN architecture, defined in [RFC8453], is used to control this
multi-domain network where each Packet PNC (P-PNC) is responsible
for controlling its IP domain (AS), and each Optical PNC (O-PNC) is
responsible for controlling its Optical Domain.
The MDSC is responsible for coordinating the whole multi-domain
multi-layer (Packet and Optical) network. A specific standard
interface (MPI) permits MDSC to interact with the different
Provisioning Network Controller (O/P-PNCs).
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The MPI interface presents an abstracted topology to MDSC hiding
technology-specific aspects of the network and hiding topology
details depending on the policy chosen regarding the level of
abstraction supported. The level of abstraction can be obtained
based on P-PNC and O-PNC configuration parameters (e.g. provide the
potential connectivity between any PE and any ABSR in an MPLS-TE
network).
The MDSC in Figure 1 is responsible for multi-domain and multi-layer
coordination across multiple Packet and Optical domains, as well as
to provide IP services to different CNCs at its CMIs using YANG-
based service models (e.g., using L2SM [RFC8466], L3SM [RFC8299]).
The multi-domain coordination mechanisms for the IP tunnels
supporting these IP services are described in section 5. In some
cases, the MDSC could also rely on the multi-layer POI mechanisms,
described in this draft, to support multi-layer optimizations for
these IP services and tunnels.
In the network scenario of Figure 1, it is assumed that:
o The domain boundaries between the IP and Optical domains are
congruent. In other words, one Optical domain supports
connectivity between Routers in one and only one Packet Domain;
o Inter-domain links exist only between Packet domains (i.e.,
between ASBR routers) and between Packet and Optical domains
(i.e., between routers and ROADMs). In other words, there are no
inter-domain links between Optical domains;
o The interfaces between the routers and the ROADM's are "Ethernet"
physical interfaces;
o The interfaces between the ASBR routers are "Ethernet" physical
interfaces.
2.1. Generic Assumptions
This section describes general assumptions which are applicable at
all the MPI interfaces, between each PNC (optical or packet) and the
MDSC, and also to all the scenarios discussed in this document.
The data models used on these interfaces are assumed to use the YANG
1.1 Data Modeling Language, as defined in [RFC7950].
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The RESTCONF protocol, as defined in [RFC8040], using the JSON
representation, defined in [RFC7951], is assumed to be used at these
interfaces.
As required in [RFC8040], the "ietf-yang-library" YANG module
defined in [RFC8525] is used to allow the MDSC to discover the set
of YANG modules supported by each PNC at its MPI.
3. Multi-Layer Topology Coordination
In this scenario, the MSDC needs to discover the network topology,
at both WDM and IP layers, in terms of nodes (NEs) and links,
including inter-AS domain links as well as cross-layer links.
Each PNC provides to the MDSC an abstract topology view of the WDM
or of the IP topology of the domain it controls. This topology is
abstracted in the sense that some detailed NE information is hidden
at the MPI, and all or some of the NEs and related physical links
are exposed as abstract nodes and logical (virtual) links, depending
on the level of abstraction the user requires. This detailed
information is vital to understand both the inter-AS domain links
(seen by each controller as UNI interfaces but as I-NNI interfaces
by the MDSC) as well as the cross-layer mapping between IP and WDM
layer.
The MDSC also maintains an up-to-date network inventory of both IP
and WDM layers through the use of IETF notifications through MPI
with the PNCs.
For the cross-layer links, the MDSC needs to be capable of
automatically correlating physical ports information from the
routers (single link or bundle links for link aggregation groups -
LAG) to client ports in the ROADM.
3.1. Discovery of existing Och, ODU, IP links, IP tunnels and IP
services
Typically, an MDSC must be able to automatically discover network
topology of both WDM and IP layers (links and NE, links between two
domains), this assumes the following:
o An abstract view of the WDM and IP topology must be available;
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o MDSC must keep an up-to-date network inventory of both IP and WDM
layers, and it should be possible to correlate such information
(e.g., which port, lambda/OTSi, the direction it is used by a
specific IP service on the WDM equipment);
o It should be possible at MDSC level to easily correlate WDM and
IP layers alarms to speed-up troubleshooting.
3.1.1. Common YANG Models used at the MPI
Both optical and packet PNCs use the following common topology YANG
models at the MPI to report their abstract topologies:
o The Base Network Model, defined in the "ietf-network" YANG module
of [RFC8345];
o The Base Network Topology Model, defined in the "ietf-network-
topology" YANG module of [RFC8345], which augments the Base
Network Model;
o The TE Topology Model, defined in the "ietf-te-topology" YANG
module of [TE-TOPO], which augments the Base Network Topology
Model.
These IETF YANG models are generic and augmented by technology-
specific YANG modules as described in the following sections.
3.1.1.1. YANG models used at the Optical MPIs
The optical PNC also uses at least the following technology-specific
topology YANG models, providing WDM and Ethernet technology-specific
augmentations of the generic TE Topology Model:
o The WSON Topology Model, defined in the "ietf-wson-topology" YANG
modules of [WSON-TOPO], or the Flexi-grid Topology Model, defined
in the "ietf-flexi-grid-topology" YANG module of [Flexi-TOPO].
o The Ethernet Topology Model, defined in the "ietf-eth-te-
topology" YANG module of [CLIENT-TOPO]
The WSON Topology Model or, alternatively, the Flexi-grid Topology
model is used to report the fixed-grid or, respectively, the
flexible-grid DWDM network topology (e.g., ROADMs and OMS links).
The Ethernet Topology Model is used to report the Ethernet access
links on the edge ROADMs.
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3.1.1.2. Required YANG models at the Packet MPIs
The Packet PNC also uses at least the following technology-specific
topology YANG models, providing IP and Ethernet technology-specific
augmentations of the generic Topology Models:
o The L3 Topology Model, defined in the "ietf-l3-unicast-topology"
YANG modules of [RFC8346], which augments the Base Network
Topology Model
o The Ethernet Topology Model, defined in the "ietf-eth-te-
topology" YANG module of [CLIENT-TOPO], which augments the TE
Topology Model
o The L3-TE Topology Model, defined in the "ietf-l3-te-topology"
YANG modules of [L3-TE-TOPO], which augments the L3 Topology
Model
The Ethernet Topology Model is used to report the Ethernet links
between the IP routers and the edge ROADMs as well as the
inter-domain links between ASBRs, while the L3 Topology Model is
used to report the IP network topology (e.g., IP routers and IP
links).
The L3-TE Topology Model reports the relationship between the IP
routers and LTPs provided by the L3 Topology Model and the
underlying Ethernet nodes and LTPs provided by the Ethernet Topology
Model.
3.1.2. Inter-domain link Discovery
In the reference network of Figure 1, there are two types of
inter-domain links:
o Links between two IP domains/ASBRs (ASes)
o Links between an IP router and a ROADM
Both types of links are Ethernet physical links.
The inter-domain link information is reported to the MDSC by the two
adjacent PNCs, controlling the two ends of the inter-domain link,
using the Ethernet Topology Model defined in [CLIENT-TOPO].
The MDSC can understand how to merge these inter-domain Ethernet
links together using the plug-id attribute defined in the TE
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Topology Model [TE-TOPO], as described in as described in section
4.3 of [TE-TOPO].
A more detailed description of how the plug-id can be used to
discover inter-domain link is also provided in section 5.1.4 of
[TNBI].
Both types of inter-domain Ethernet links are discovered using the
plug-id attributes reported in the Ethernet Topologies exposed by
the two adjacent PNCs.
The MDSC, when discovering an Ethernet inter-domain link between two
Ethernet LTPs which are associated with two IP LTPs, reported in the
IP Topologies exposed by the two adjacent P-PNCs, can also discover
an inter-domain IP link/adjacency between these two IP LTPs.
Two options are possible to discover these inter-domain Ethernet
links:
1. Static configuration
2. LLDP [IEEE 802.1AB] automatic discovery
Since the static configuration requires an administrative burden to
configure network-wide unique identifiers, the automatic discovery
solution based on LLDP is preferable when LLDP is supported.
As outlined in [TNBI], the encoding of the plug-id namespace as well
as of the LLDP information within the plug-id value is
implementation specific and needs to be consistent across all the
PNCs.
3.2. Provisioning of an IP Link/LAG over DWDM
In this scenario, the MSDC needs to coordinate the creation of an IP
link, or a LAG, between two routers through a DWDM network.
It is assumed that the MDSC has already discovered the whole network
topology as described in section 3.1.
3.2.1. YANG models used at the MPIs
3.2.1.1. YANG models used at the Optical MPIs
The optical PNC uses at least the following YANG models:
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o The TE Tunnel Model, defined in the "ietf-te" YANG module of
[TE-TUNNEL]
o The WSON Tunnel Model, defined in the "ietf-wson-tunnel" YANG
modules of [WSON-TUNNEL], or the Flexi-grid Media Channel Model,
defined in the "ietf-flexi-grid-media-channel" YANG module of
[Flexi-MC]
o The Ethernet Client Signal Model, defined in the "ietf-eth-tran-
service" YANG module of [CLIENT-SIGNAL]
The TE Tunnel model is generic and augmented by technology-specific
models such as the WSON Tunnel Model and the Flexi-grid Media
Channel Model.
The WSON Tunnel Model or, alternatively, the Flexi-grid Media
Channel Model are used to setup connectivity within the DWDM network
depending on whether the DWDM optical network is based on fixed grid
or flexible-grid.
The Ethernet Client Signal Model is used to configure the steering
of the Ethernet client traffic between Ethernet access links and TE
Tunnels, which in this case could be either WSON Tunnels or
Flexi-Grid Media Channels. This model is generic and applies to any
technology-specific TE Tunnel: technology-specific attributes are
provided by the technology-specific models which augment the generic
TE-Tunnel Model.
3.2.1.2. Required YANG models at the Packet MPIs
The Packet PNC uses at least the following topology YANG models:
o The Base Network Model, defined in the "ietf-network" YANG module
of [RFC8345] (see section 3.1.1)
o The Base Network Topology Model, defined in the "ietf-network-
topology" YANG module of [RFC8345] (see section 3.1.1)
o The L3 Topology Model, defined in the "ietf-l3-unicast-topology"
YANG modules of [RFC8346] (see section 3.1.1.1)
If, as discussed in section 3.2.2, IP Links created over DWDM can be
automatically discovered by the P-PNC, the IP Topology is needed
only to report these IP Links after being discovered by the P-PNC.
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The IP Topology can also be used to configure the IP Links created
over DWDM.
3.2.2. IP Link Setup Procedure
The MDSC requires the O-PNC to setup a WDM Tunnel (either a WSON
Tunnel or a Flexi-grid Tunnel) within the DWDM network between the
two Optical Transponders (OTs) associated with the two access links.
The Optical Transponders are reported by the O-PNC as Trail
Termination Points (TTPs), defined in [TE-TOPO], within the WDM
Topology. The association between the Ethernet access link and the
WDM TTP is reported by the Inter-Layer Lock (ILL) identifiers,
defined in [TE-TOPO], reported by the O-PNC within the Ethernet
Topology and WDM Topology.
The MDSC also requires the O-PNC to steer the Ethernet client
traffic between the two access Ethernet Links over the WDM Tunnel.
After the WDM Tunnel has been setup and the client traffic steering
configured, the two IP routers can exchange Ethernet packets between
themselves, including LLDP messages.
If LLDP [IEEE 802.1AB] is used between the two routers, the P-PNC
can automatically discover the IP Link being set up by the MDSC. The
IP LTPs terminating this IP Link are supported by the ETH LTPs
terminating the two access links.
Otherwise, the MDSC needs to require the P-PNC to configure an IP
Link between the two routers: the MDSC also configures the two ETH
LTPs which support the two IP LTPs terminating this IP Link.
3.3. Provisioning of an IP link/LAG over DWDM with path constraints
MDSC must be able to provision an IP link with a fixed maximum
latency constraint, or with the minimum latency available constraint
within each domain but as well inter-domain when required (e.g. by
monitoring traffic KPIs trends for this IP link). Through the O-PNC
fixed latency path/minimum latency path is chosen between PE and
ASBR in each optical domain. Then MDSC needs to select the inter-AS
domain with less latency (in case we have several interconnection
links) to have the right low latency constraint fulfilled end-to-end
across domains.
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MDSC must be able to automatically create two IP links between two
routers, over DWDM network, with physical path diversity (avoiding
SRLGs communicated by O-PNCs to the MDSC).
MDSC must be responsible for routing each of this IP links through
different inter-AS domain links so that end-to-end IP links are
fully disjoint.
Optical connectivity must be set up accordingly by MDSC through O-
PNCs.
3.3.1. YANG models used at the MPIs
This section is for further study
3.4. Provisioning Link Members to an existing LAG
When adding a new link member to a LAG between two routers with or
without path latency/diversity constraint, the MDSC must be able to
force the additional optical connection to use the same physical
path in the optical domain where the LAG capacity increase is
required.
3.4.1. YANG Models used at the MPIs
This is for further study
4. Multi-Layer Recovery Coordination
4.1. Ensuring Network Resiliency during Maintenance Events
Before planned maintenance operation on DWDM network takes place, IP
traffic should be moved hitless to another link.
MDSC must reroute IP traffic before the events takes place. It
should be possible to lock IP traffic to the protection route until
the maintenance event is finished, unless a fault occurs on such
path.
4.2. Router Port Failure
The focus is on client-side protection scheme between IP router and
reconfigurable ROADM. Scenario here is to define only one port in
the routers and in the ROADM muxponder board at both ends as back-up
ports to recover any other port failure on client-side of the ROADM
(either on router port side or on muxponder side or on the link
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between them). When client-side port failure occurs, alarms are
raised to MDSC by IP-PNC and O-PNC (port status down, LOS etc.).
MDSC checks with OP-PNC(s) that there is no optical failure in the
optical layer.
There can be two cases here:
a) LAG was defined between the two end routers. MDSC, after checking
that optical layer is fine between the two end ROADMs, triggers
the ROADM configuration so that the router back-up port with its
associated muxponder port can reuse the OCh that was already in
use previously by the failed router port and adds the new link to
the LAG on the failure side.
While the ROADM reconfiguration takes place, IP/MPLS traffic is
using the reduced bandwidth of the IP link bundle, discarding
lower priority traffic if required. Once backup port has been
reconfigured to reuse the existing OCh and new link has been
added to the LAG then original Bandwidth is recovered between the
end routers.
Note: in this LAG scenario let assume that BFD is running at LAG
level so that there is nothing triggered at MPLS level when one
of the link member of the LAG fails.
b) If there is no LAG then the scenario is not clear since a router
port failure would automatically trigger (through BFD failure)
first a sub-50ms protection at MPLS level :FRR (MPLS RSVP-TE
case) or TI-LFA (MPLS based SR-TE case) through a protection
port. At the same time MDSC, after checking that optical network
connection is still fine, would trigger the reconfiguration of
the back-up port of the router and of the ROADM muxponder to re-
use the same OCh as the one used originally for the failed router
port. Once everything has been correctly configured, MDSC Global
PCE could suggest to the operator to trigger a possible re-
optimisation of the back-up MPLS path to go back to the MPLS
primary path through the back-up port of the router and the
original OCh if overall cost, latency etc. is improved. However,
in this scenario, there is a need for protection port PLUS back-
up port in the router which does not lead to clear port savings.
5. Service Coordination for Multi-Layer network
[Editors' Note] This text has been taken from section 2 of draft-
lee-teas-actn-poi-applicability-00 and need to be reconciled with
the other sections (the introduction in particular) of this document
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This section provides a number of deployment scenarios for packet
and optical integration (POI). Specifically, this section provides a
deployment scenario in which ACTN hierarchy is deployed to control a
multi-layer and multi-domain network via two IP/MPLS PNCs and two
Optical PNCs with coordination with L-MDSC. This scenario is in the
context of an upper layer service configuration (e.g. L3VPN) across
two AS domains which are transported by two transport underlay
domains (e.g. OTN).
The provisioning of the L3VPN service is outside ACTN scope but it
is worth showing how the L3VPN service provisioning is integrated
for the end-to-end service fulfilment in ACTN context. An example of
service configuration function in the Service/Network Orchestrator
is discussed in [BGP-L3VPN].
Figure 2 shows an ACTN POI Reference Architecture where it shows
ACTN components as well as non-ACTN components that are necessary
for the end-to-end service fulfilment. Both IP/MPLS and Optical
Networks are multi-domain. Each IP/MPLS domain network is controlled
by its' domain controller and all the optical domains are controlled
by a hierarchy of optical domain controllers. The L-MDSC function of
the optical domain controllers provides an abstract view of the
whole optical network to the Service/Network Orchestrator. It is
assumed that all these components of the network belong to one
single network operator domain under the control of the
service/network orchestrator.
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Customer
+-------------------------------+
| +-----+ +------------+ |
| | CNC |----| Service Op.| |
| +-----+ +------------+ |
+-------|------------------|----+
| ACTN interface | Non-ACTN interface
| CMI | (Customer Service model)
Service/Network| +-----------------+
Orchestrator | |
+-----|------------------------------------|-----------+
| +----------------------------------+ | |
| |MDSC TE & Service Mapping Function| | |
| +----------------------------------+ | |
| | | | |
| +------------------+ +---------------------+ |
| | MDSC NP Function |-------|Service Config. Func.| |
| +------------------+ +---------------------+ |
+------|---------------------------|-------------------+
MPI | +---------------------+--+
| / Non-ACTN interface \
+-------+---/-------+------------+ \
IP/MPLS | / |Optical | \ IP/MPLS
Domain 1 | / |Domain | \ Domain 2
Controller| / |Controller | \ Controller
+------|-------/--+ +---|-----+ +--|-----------\----+
| +-----+ +-----+| | +-----+ | |+------+ +------+|
| |PNC1 | |Serv.|| | |PNC | | || PNC2 | | Serv.||
| +-----+ +----- | | +-----+ | |+------+ +------+|
+-----------------+ +---------+ +-------------------+
SBI | | | SBI
v | V
+------------------+ | +------------------+
/ IP/MPLS Network \ | / IP/MPLS Network \
+----------------------+ | SBI +----------------------+
v
+-------------------------------+
/ Optical Network \
+-----------------------------------+
Figure 2 ACTN POI Reference Architecture
Figure 2 shows ACTN POI Reference Architecture where it depicts:
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o CMI (CNC-MDSC Interface) interfacing CNC with MDSC function in
the Service/Network Orchestrator. This is where TE & Service
Mapping [TSM] and either ACTN VN [ACTN-VN] or TE-topology [TE-
TOPO] model is exchanged over CMI.
o Customer Service Model Interface: Non-ACTN interface in the
Customer Portal interfacing Service/Network Orchestrator's
Service Configuration Function. This is the interface where L3SM
information is exchanged.
o MPI (MDSC-PNC Interface) interfacing IP/MPLS Domain Controllers
and Optical Domain Controllers.
o Service Configuration Interface: Non-ACTN interface in
Service/Network Orchestrator interfacing with the IP/MPLS Domain
Controllers to coordinate L2/L3VPN multi-domain service
configuration. This is where service specific information such as
VPN, VPN binding policy (e.g., new underlay tunnel creation for
isolation), etc. are conveyed.
o SBI (South Bound Interface): Non-ACTN interface in the domain
controller interfacing network elements in the domain.
Please note that MPI and Service Configuration Interface can be
implemented as the same interface with the two different
capabilities. The split is just functional but doesn't have to be
also logical.
The following sections are provided to describe key functions that
are necessary for the vertical as well as horizontal end-to-end
service fulfilment of POI.
5.1. L2/L3VPN/VN Service Request by the Customer
A customer can request L3VPN services with TE requirements using
ACTN CMI models (i.e., ACTN VN YANG, TE & Service Mapping YANG) and
non-ACTN customer service models such as L2SM/L3SM YANG together.
Figure 3 shows detailed control flow between customer and
service/network orchestrator to instantiate L2/L3VPN/VN service
request.
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Customer
+-------------------------------------------+
| +-----+ +------------+ |
| | CNC |--------------| Service Op.| |
| +-----+ +------------+ |
+-------|------------------------|----------+
2. VN & TE/Svc | | 1.L2/3SM
Mapping | | |
| | ^ | |
| | | | |
v | | 3. Update VN | v
| & TE/Svc |
Service/Network | mapping |
Orchestrator | |
+------------------|------------------------|-----------+
| +----------------------------------+ | |
| |MDSC TE & Service Mapping Function| | |
| +----------------------------------+ | |
| | | | |
| +------------------+ +---------------------+ |
| | MDSC NP Function |-------|Service Config. Func.| |
| +------------------+ +---------------------+ |
+-------|-----------------------------------|-----------+
NP: Network Provisioning
Figure 3 Service Request Process
o ACTN VN YANG provides VN Service configuration, as specified in
[ACTN-VN].
o It provides the profile of VN in terms of VN members, each of
which corresponds to an edge-to-edge link between customer
end-points (VNAPs). It also provides the mappings between the
VNAPs with the LTPs and between the connectivity matrix with
the VN member from which the associated traffic matrix (e.g.,
bandwidth, latency, protection level, etc.) of VN member is
expressed (i.e., via the TE-topology's connectivity matrix).
o The model also provides VN-level preference information
(e.g., VN member diversity) and VN-level admin-status and
operational-status.
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o L2SM YANG [RFC8466] provides all L2VPN service configuration and
site information from a customer/service point of view.
o L3SM YANG [RFC8299] provides all L3VPN service configuration and
site information from a customer/service point of view.
o The TE & Service Mapping YANG model [TSM] provides TE-service
mapping as well as site mapping.
o TE-service mapping provides the mapping of L3VPN instance
from [RFC8299] with the corresponding ACTN VN instance.
o The TE-service mapping also provides the service mapping
requirement type as to how each L2/L3VPN/VN instance is
created with respect to the underlay TE tunnels (e.g.,
whether the L3VPN requires a new and isolated set of TE
underlay tunnels or not, etc.). See Section 5.2 for detailed
discussion on the mapping requirement types.
o Site mapping provides the site reference information across
L2/L3VPN Site ID, ACTN VN Access Point ID, and the LTP of the
access link.
5.2. Service and Network Orchestration
The Service/Network orchestrator shown in Figure 2 interfaces the
customer and decouples the ACTN MDSC functions from the customer
service configuration functions.
An implementation can choose to split the Service/Network
orchestration functions, as described in [RFC8309] and in section
4.2 of [RFC8453], between a top-level Service Orchestrator
interfacing the customer and two low-level Network Orchestrators,
one controlling a multi-domain IP/MPLS network and the other
controlling the Optical networks.
Another implementation can choose to combine the L-MDSC functions of
the Optical hierarchical controller, providing multi-domain
coordination of the Optical network together with the MDSC functions
in the Service/Network orchestrator.
Without loss of generality, this assumes that the service/network
orchestrator as depicted in Figure 2 would include all the required
functionalities as in a hierarchical orchestration case.
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One of the important service functions the Service/Network
orchestrator performs is to identify which TE Tunnels should carry
the L3VPN traffic (from TE & Service Mapping Model) and to relay
this information to the IP/MPLS domain controllers, via non-ACTN
interface, to ensure proper IP/VRF forwarding table be populated
according to the TE binding requirement for the L3VPN.
[Editor's Note] What mechanism would convey on the interface to the
IP/MPLS domain controllers as well as on the SBI (between IP/MPLS
domain controllers and IP/MPLS PE routers) the TE binding policy
dynamically for the L3VPN? Typically, VRF is the function of the
device that participate MP-BGP in MPLS VPN. With current MP-BGP
implementation in MPLS VPN, the VRF's BGP next hop is the
destination PE and the mapping to a tunnel (either an LDP or a BGP
tunnel) toward the destination PE is done by automatically without
any configuration. It is to be determined the impact on the PE VRF
operation when the tunnel is an optical bypass tunnel which does not
participate either LDP or BGP.
Figure 4 shows service/network orchestrator interactions with
various domain controllers to instantiate tunnel provisioning as
well as service configuration.
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+-------|----------------------------------|-----------+
| +----------------------------------+ | |
| |MDSC TE & Service Mapping Function| | |
| +----------------------------------+ | |
| | | | |
| +------------------+ +---------------------+ |
| | MDSC NP Function |-------|Service Config. Func.| |
| +------------------+ +---------------------+ |
+-------|------------------------------|---------------+
| |
| +-------------------+------+ 3.
2. Inter-layer | / \ VPN
Serv.
tunnel +-----+--------/-------+-----------------+
\provision
binding| / | 1. Optical | \
| / | tunnel creation | \
+----|-----------/-+ +---|------+ +-----|-------\---+
| +-----+ +-----+ | | +------+ | | +-----+ +-----+|
| |PNC1 | |Serv.| | | | PNC | | | |PNC2 | |Serv.||
| +-----+ +-----+ | | +------+ | | +-----+ +-----+|
+------------------+ +----------+ +-----------------+
Figure 4 Service and Network Orchestration Process
TE binding requirement types [TSM] are:
1. Hard Isolation with deterministic latency: Customer would request
an L3VPN service [RFC8299] using a set of TE Tunnels with a
deterministic latency requirement and that cannot be not shared
with other L3VPN services nor compete for bandwidth with other
Tunnels.
2. Hard Isolation: This is similar to the above case without
deterministic latency requirements.
3. Soft Isolation: Customer would request an L3VPN service using a
set of MPLS-TE tunnel which cannot be shared with other L3VPN
services.
4. Sharing: Customer would accept sharing the MPLS-TE Tunnels
supporting its L3VPN service with other services.
For the first three types, there could be additional TE binding
requirements with respect to different VN members of the same VN
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associated with an L3VPN service. For the first two cases, VN
members can be hard-isolated, soft-isolated, or shared. For the
third case, VN members can be soft-isolated or shared.
o When "Hard Isolation with or w/o deterministic latency" (i.e.,
the first and the second type) TE binding requirement is applied
for a L3VPN, a new optical layer tunnel has to be created (Step 1
in Figure 4). This operation requires the following control level
mechanisms as follows:
o The MDSC function of the Service/Network Orchestrator
identifies only the domains in the IP/MPLS layer in which the
VPN needs to be forwarded.
o Once the IP/MPLS layer domains are determined, the MDSC
function of the Service/Network Orchestrator needs to
identify the set of optical ingress and egress points of the
underlay optical tunnels providing connectivity between the
IP/MPLS layer domains.
o Once both IP/MPLS layers and optical layer are determined,
the MDSC needs to identify the inter-layer peering points in
both IP/MPLS domains as well as the optical domain(s). This
implies that the L3VPN traffic will be forwarded to an MPLS-
TE tunnel that starts at the ingress PE (in one IP/MPLS
domain) and terminates at the egress PE (in another IP/MPLS
domain) via a dedicated underlay optical tunnel.
o The MDSC function of the Service/Network Orchestrator needs to
first request the optical L-MDSC to instantiate an optical tunnel
for the optical ingress and egress. This is referred to as
optical tunnel creation (Step 1 in Figure 4). Note that it is L-
MDSC responsibility to perform multi-domain optical coordination
with its underlying optical PNCs, for setting up a multi-domain
optical tunnel.
o Once the optical tunnel is established, then the MDSC function of
the Service/Network Orchestrator needs to coordinate with the PNC
functions of the IP/MPLS Domain Controllers (under which the
ingress and egress PEs belong) the setup of a multi-domain MPLS-
TE Tunnel, between the ingress and egress PEs. This setup is
carried by the created underlay optical tunnel (Step 2 in Figure
4).
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o It is the responsibility of the Service Configuration Function of
the Service/Network Orchestrator to identify interfaces/labels on
both ingress and egress PEs and to convey this information to
both the IP/MPLS Domain Controllers (under which the ingress and
egress PEs belong) for proper configuration of the L3VPN (BGP and
VRF function of the PEs) in their domain networks (Step 3 in
Figure 4).
5.3. IP/MPLS Domain Controller and NE Functions
IP/MPLS networks are assumed to have multiple domains and each
domain is controlled by IP/MPLS domain controller in which the ACTN
PNC functions and non-ACTN service functions are performed by the
IP/MPLS domain controller.
Among the functions of the IP/MPLS domain controller are VPN service
aspect provisioning such as VRF control and management for VPN
services, etc. It is assumed that BGP is running in the inter-domain
IP/MPLS networks for L2/L3VPN and that the IP/MPLS domain controller
is also responsible for configuring the BGP speakers within its
control domain if necessary.
Depending on the TE binding requirement types discussed in Section
5.2, there are two possible deployment scenarios.
5.3.1. Scenario A: Shared Tunnel Selection
When the L2/L3VPN does not require isolation (either hard or soft),
it can select an existing MPLS-TE and Optical tunnel between ingress
and egress PE, without creating any new TE tunnels. Figure 5 shows
this scenario.
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IP/MPLS Domain 1 IP/MPLS Domain 2
Controller Controller
+------------------+ +------------------+
| +-----+ +-----+ | | +-----+ +-----+ |
| |PNC1 | |Serv.| | | |PNC2 | |Serv.| |
| +-----+ +-----+ | | +-----+ +-----+ |
+--|-----------|---+ +--|-----------|---+
| 1.Tunnel | 2.VPN/VRF | 1.Tunnel | 2.VPN/VRF
| Selection | Provisioning | Selection |
Provisioning
V V V V
+---------------------+ +---------------------+
CE / PE tunnel 1 ASBR\ /ASBR tunnel 2 PE \
CE
o--/---o..................o--\--------/--o..................o---
\--o
\ / \ /
\ AS Domain 1 / \ AS Domain 2 /
+---------------------+ +---------------------+
End-to-end tunnel
<----------------------------------------------------->
Figure 5 IP/MPLS Domain Controller & NE Functions
How VPN is disseminated across the network is out of the scope of
this document. We assume that MP-BGP is running in IP/MPLS networks
and VPN is made known to ABSRs and PEs by each IP/MPLS domain
controllers. See [RFC4364] for detailed descriptions on how MP-BGP
works.
There are several functions IP/MPLS domain controllers need to
provide in order to facilitate tunnel selection for the VPN in both
domain level and end-to-end level.
5.3.1.1. Domain Tunnel Selection
Each domain IP/MPLS controller is responsible for selecting its
domain level tunnel for the L3VPN. First it needs to determine which
existing tunnels would fit for the L2/L3VPN requirements allotted to
the domain by the Service/Network Orchestrator (e.g., tunnel
binding, bandwidth, latency, etc.). If there are existing tunnels
that are feasible to satisfy the L3VPN requirements, the IP/MPLS
domain controller selects the optimal tunnel from the candidate
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pool. Otherwise, an MPLS tunnel with modified bandwidth or a new
MPLS Tunnel needs to be setup. Note that with no isolation
requirement for the L3VPN, existing MPLS tunnel can be selected.
With soft isolation requirement for the L3VPN, an optical tunnel can
be shared with other L2/L3VPN services while with hard isolation
requirement for the L2/L3VPN, a dedicated MPLS-TE and a dedicated
optical tunnel MUST be provisioned for the L2/L3VPN.
5.3.1.2. VPN/VRF Provisioning for L3VPN
Once the domain level tunnel is selected for a domain, the Service
Function of the IP/MPLS domain controller maps the L3VPN to the
selected MPLS-TE tunnel and assigns a label (e.g., MPLS label) with
the PE. Then the PE creates a new entry for the VPN in the VRF
forwarding table so that when the VPN packet arrives to the PE, it
will be able to direct to the right interface and PUSH the label
assigned for the VPN. When the PE forwards a VPN packet, it will
push the VPN label signaled by BGP and, in case of option A and B
[RFC4364], it will also push the LSP label assigned to the
configured MPLS-TE Tunnel to reach the ASBR next hop and forwards
the packet to the MPLS next-hop of this MPLS-TE Tunnel.
In case of option C [RFC4364], the PE will push one MPLS LSP label
signaled by BGP to reach the destination PE and a second MPLS LSP
label assigned to the configured MPLS-TE Tunnel to reach the ASBR
next-hop and forward the packet to the MPLS next-hop of this MPLS-TE
Tunnel.
With Option C, the ASBR of the first domain interfacing the next
domain should keep the VPN label intact to the ASBR of the next
domain so that the ASBR in the next domain sees the VPN packets as
if they are coming from a CE. With Option B, the VPN label is
swapped. With option A, the VPN label is removed.
With Option A and B, the ASBR of the second domain does the same
procedure that includes VPN/VRF tunnel mapping and interface/label
assignment with the IP/MPLS domain controller. With option A, the
ASBR operations are the same as of the PEs. With option B, the ASBR
operates with VPN labels so it can see the VPN the traffic belongs
to. With option C, the ASBR operates with the end-to-end tunnel
labels so it may be not aware of the VPN the traffic belongs to.
This process is repeated in each domain. The PE of the last domain
interfacing the destination CE should recognize the VPN label when
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the VPN packets arrive and thus POP the VPN label and forward the
packets to the CE.
5.3.1.3. VSI Provisioning for L2VPN
The VSI provisioning for L2VPN is similar to the VPN/VRF provision
for L3VPN. L2VPN service types include:
o Point-to-point Virtual Private Wire Services (VPWSs) that use
LDP-signaled Pseudowires or L2TP-signaled Pseudowires [RFC6074];
o Multipoint Virtual Private LAN Services (VPLSs) that use LDP-
signaled Pseudowires or L2TP-signaled Pseudowires [RFC6074];
o Multipoint Virtual Private LAN Services (VPLSs) that use a Border
Gateway Protocol (BGP) control plane as described in [RFC4761]and
[RFC6624];
o IP-Only LAN-Like Services (IPLSs) that are a functional subset of
VPLS services [RFC7436];
o BGP MPLS-based Ethernet VPN Services as described in [RFC7432]
and [RFC7209];
o Ethernet VPN VPWS specified in [RFC8214] and [RFC7432].
5.3.1.4. Inter-domain Links Update
In order to facilitate inter-domain links for the VPN, we assume
that the service/network orchestrator would know the inter-domain
link status and its resource information (e.g., bandwidth available,
protection/restoration policy, etc.) via some mechanisms (which are
beyond the scope of this document). We also assume that the inter-
domain links are pre-configured prior to service instantiation.
5.3.1.5. End-to-end Tunnel Management
It is foreseen that the Service/Network orchestrator should control
and manage end-to-end tunnels for VPNs per VPN policy.
As discussed in [ACTN-PM], the Orchestrator is responsible to
collect domain LSP-level performance monitoring data from domain
controllers and to derive and report end-to-end tunnel performance
monitoring information to the customer.
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5.3.2. Scenario B: Isolated VN/Tunnel Establishment
When the L3VPN requires hard-isolated Tunnel establishment, optical
layer tunnel binding with IP/MPLS layer is necessary. As such, the
following functions are necessary.
o The IP/MPLS Domain Controller of Domain 1 needs to send the VRF
instruction to the PE:
o To the Ingress PE of AS Domain 1: Configuration for each
L3VPN destination IP address (in this case the remote CE's IP
address for the VPN or any customer's IP addresses reachable
through a remote CE) of the associated VPN label assigned by
the Egress PE and of the MPLS-TE Tunnel to be used to reach
the Egress PE: so that the proper VRF table is populated to
forward the VPN traffic to the inter-layer optical interface
with the VPN label.
o The Egress PE, upon the discovery of a new IP address, needs to
send the mapping information (i.e., VPN to IP address) to its'
IP/MPLS Domain Controller of Domain 2 which sends, in turn, to
the service orchestrator. The service orchestrator would then
propagate this mapping information to the IP/MPLS Domain
Controller of Domain 1 which sends it, in turn, to the ingress PE
so that it may override the VPN/VRF forwarding or VSI forwarding,
respectively for L3VPN and L2VPN. As a result, when packets
arriving at the ingress PE with that IP destination address, the
ingress PE would then forward this packet to the inter-layer
optical interface.
[Editor's Note] in case of hard isolated tunnel required for the
VPN, we need to create a separate MPLS TE tunnel and encapsulate the
MPLS packets of the MPLS Tunnel into the ODU so that the optical NE
would route this MPLS Tunnel to a separate optical tunnel from other
tunnels.]
5.4. Optical Domain Controller and NE Functions
Optical network provides the underlay connectivity services to
IP/MPLS networks. The multi-domain optical network coordination is
performed by the L-MDSC function shown in Figure 2 so that the whole
multi-domain optical network appears to the service/network
orchestrator as one optical network. The coordination of
Packet/Optical multi-layer and IP/MPLS multi-domain is done by the
service/network orchestrator where it interfaces two IP/MPLS domain
controllers and one optical L-MDSC.
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Figure 6 shows how the Optical Domain Controllers create a new
optical tunnel and the related interaction with IP/MPLS domain
controllers and the NEs to bind the optical tunnel with proper
forwarding instruction so that the VPN requiring hard isolation can
be fulfilled.
IP/MPLS Domain 1 Optical Domain IP/MPLS Domain 2
Controller Controller Controller
+------------------+ +---------+ +------------------+
| +-----+ +-----+ | | +-----+ | | +-----+ +-----+ |
| |PNC1 | |Serv.| | | |PNC | | | |PNC2 | |Serv.| |
| +-----+ +-----+ | | +-----+ | | +-----+ +-----+ |
+--|-----------|---+ +----|----+ +--|----------|----+
| 2.Tunnel | 3.VPN/VRF | |2.Tunnel | 3.VPN/VRF
| Binding | Provisioning| |Binding |
Provisioning
V V | V V
+-------------------+ | +-------------------+
CE / PE ASBR\ | /ASBR PE \ CE
o--/---o o--\----|--/--o o---\--o
\ : / | \ : /
\ : AS Domain 1 / | \ AS Domain 2 : /
+-:-----------------+ | +-----------------:-+
: | :
: | 1. Optical :
: | Tunnel Creation :
: v :
+-:--------------------------------------------------:-+
/ : : \
/ o..................................................o \
| Optical Tunnel |
\ /
\ Optical Domain /
+------------------------------------------------------+
Figure 6 Domain Controller & NE Functions (Isolated Optical Tunnel)
As discussed in 5.2, in case that VPN has requirement for hard-
isolated tunnel establishment, the service/network orchestrator will
coordinate across IP/MPLS domain controllers and Optical L-MDSC to
ensure the creation of a new optical tunnel for the VPN in proper
sequence. Figure 6 shows this scenario.
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o The MDSC of the service/network orchestrator requests the L-MDSC
to setup and Optical tunnel providing connectivity between the
inter-layer interfaces at the ingress and egress PEs and requests
the two IP/MPLS domain controllers to setup an inter-domain IP
link between these interfaces
o The MDSC of the service/network orchestrator then should provide
the ingress IP/MPLS domain controller with the routing
instruction for the VPN so that the ingress IP/MPLS domain
controller would help its ingress PE to populate forwarding
table. The packet with the VPN label should be forwarded to the
optical interface the MDSC provided.
o The Ingress Optical Domain PE needs to recognize MPLS-TE label on
its ingress interface from IP/MPLS domain PE and encapsulate the
MPLS packets of this MPLS-TE Tunnel into the ODU.
[Editor's Note] We assumed that the Optical PE is LSR.]
o The Egress Optical Domain PE needs to POP the ODU label before
sending the packet (with MPLS-TE label kept intact at the top
level) to the Egress PE in the IP/MPLS Domain to which the packet
is destined.
[Editor's Note] If there are two VPNs having the same destination CE
requiring non-shared optical tunnels from each other, we need to
explain this case with a need for additional Label to differentiate
the VPNs]
5.5. Orchestrator-Controllers-NEs Communication Protocol Flows
This section provides generic communication protocol flows across
orchestrator, controllers and NEs in order to facilitate the POI
scenarios discussed in Section 5.3.2 for dynamic optical Tunnel
establishment. Figure 7 shows the communication flows.
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+---------+ +-------+ +------+ +------+ +------+ +------+
|Orchestr.| |Optical| |Packet| |Packet| |Ing.PE| |Egr.PE|
| | | Ctr. | |Ctr-D1| |Ctr-D2| | D1 | | D2 |
+---------+ +-------+ +------+ +------+ +------+ +------+
| | | | | |
| | | | |<--BGP--->|
| | | |VPN Update | |
| | | VPN Update|<---------------------|
|<--------------------------------------|(Dest, VPN)| |
| | |(Dest, VPN)| | |
| Tunnel Create | | | | |
|---------------->| | | | |
|(VPN,Ingr/Egr if)| | | | |
| | | | | |
| Tunnel Confirm | | | | |
|<----------------| | | | |
| (Tunnel ID) | | | | |
| | | | | |
| Tunnel Bind | | | | |
|-------------------------->| | | |
| (Tunnel ID, VPN, Ingr if) | Forward. Mapping | |
| | |---------------------->| (1) |
| Tunnel Bind Confirm | (Dest, VPN, Ingr if | |
|<--------------------------| | | |
| | | | | |
| Tunnel Bind | | | | |
|-------------------------------------->| | |
| (Tunnel ID, VPN, Egr if) | | | |
| | | | Forward. Mapping |
| | | |---------------------
>|(2)
| | | | (Dest, VPN , Egr if) |
| | Tunnel Bind Confirm | | |
|<--------------------------------------| | |
| | | | | |
Figure 7 Communication Flows for Optical Tunnel Establishment and
binding.
When Domain Packet Controller 1 sends the forwarding mapping
information as indicated in (1) in Figure 7, the Ingress PE in
Domain 1 will need to provision the VRF forwarding table based on
the information it receives. Please see the detailed procedure in
section 5.3.1.2. A similar procedure is to be done at the Egress PE
in Domain 2.
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6. Security Considerations
Several security considerations have been identified and will be
discussed in future versions of this document.
7. Operational Considerations
Telemetry data, such as the collection of lower-layer networking
health and consideration of network and service performance from POI
domain controllers, may be required. These requirements and
capabilities will be discussed in future versions of this document.
8. IANA Considerations
This document requires no IANA actions.
9. References
9.1. Normative References
[RFC7950] Bjorklund, M. et al., "The YANG 1.1 Data Modeling
Language", RFC 7950, August 2016.
[RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG", RFC
7951, August 2016.
[RFC8040] Bierman, A. et al., "RESTCONF Protocol", RFC 8040, January
2017.
[RFC8345] Clemm, A., Medved, J. et al., "A Yang Data Model for
Network Topologies", RFC8345, March 2018.
[RFC8346] Clemm, A. et al., "A YANG Data Model for Layer 3
Topologies", RFC8346, March 2018.
[RFC8453] Ceccarelli, D., Lee, Y. et al., "Framework for Abstraction
and Control of TE Networks (ACTN)", RFC8453, August 2018.
[RFC8525] Bierman, A. et al., "YANG Library", RFC 8525, March 2019.
[IEEE 802.1AB] IEEE 802.1AB-2016, "IEEE Standard for Local and
metropolitan area networks - Station and Media Access
Control Connectivity Discovery", March 2016.
[TE-TOPO] Liu, X. et al., "YANG Data Model for TE Topologies",
draft-ietf-teas-yang-te-topo, work in progress.
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[WSON-TOPO] Lee, Y. et al., " A YANG Data Model for WSON (Wavelength
Switched Optical Networks)", draft-ietf-ccamp-wson-yang,
work in progress.
[Flexi-TOPO] Lopez de Vergara, J. E. et al., "YANG data model for
Flexi-Grid Optical Networks", draft-ietf-ccamp-flexigrid-
yang, work in progress.
[CLIENT-TOPO] Zheng, H. et al., "A YANG Data Model for Client-layer
Topology", draft-zheng-ccamp-client-topo-yang, work in
progress.
[L3-TE-TOPO] Liu, X. et al., "YANG Data Model for Layer 3 TE
Topologies", draft-ietf-teas-yang-l3-te-topo, work in
progress.
[TE-TUNNEL] Saad, T. et al., "A YANG Data Model for Traffic
Engineering Tunnels and Interfaces", draft-ietf-teas-yang-
te, work in progress.
[WSON-TUNNEL] Lee, Y. et al., "A Yang Data Model for WSON Tunnel",
draft-ietf-ccamp-wson-tunnel-model, work in progress.
[Flexi-MC] Lopez de Vergara, J. E. et al., "YANG data model for
Flexi-Grid media-channels", draft-ietf-ccamp-flexigrid-
media-channel-yang, work in progress.
[CLIENT-SIGNAL] Zheng, H. et al., "A YANG Data Model for Transport
Network Client Signals", draft-ietf-ccamp-client-signal-
yang, work in progress.
9.2. Informative References
[RFC4364] E. Rosen and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, February 2006.
[RFC4761] K. Kompella, Ed., Y. Rekhter, Ed., "Virtual Private LAN
Service (VPLS) Using BGP for Auto-Discovery and
Signaling", RFC 4761, January 2007.
[RFC6074] E. Rosen, B. Davie, V. Radoaca, and W. Luo, "Provisioning,
Auto-Discovery, and Signaling in Layer 2 Virtual Private
Networks (L2VPNs)", RFC 6074, January 2011.
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[RFC6624] K. Kompella, B. Kothari, and R. Cherukuri, "Layer 2
Virtual Private Networks Using BGP for Auto-Discovery and
Signaling", RFC 6624, May 2012.
[RFC7209] A. Sajassi, R. Aggarwal, J. Uttaro, N. Bitar, W.
Henderickx, and A. Isaac, "Requirements for Ethernet VPN
(EVPN)", RFC 7209, May 2014.
[RFC7432] A. Sajassi, Ed., et al., "BGP MPLS-Based Ethernet VPN",
RFC 7432, February 2015.
[RFC7436] H. Shah, E. Rosen, F. Le Faucheur, and G. Heron, "IP-Only
LAN Service (IPLS)", RFC 7436, January 2015.
[RFC8214] S. Boutros, A. Sajassi, S. Salam, J. Drake, and J.
Rabadan, "Virtual Private Wire Service Support in Ethernet
VPN", RFC 8214, August 2017.
[RFC8299] Q. Wu, S. Litkowski, L. Tomotaki, and K. Ogaki, "YANG Data
Model for L3VPN Service Delivery", RFC 8299, January 2018.
[RFC8309] Q. Wu, W. Liu, and A. Farrel, "Service Model Explained",
RFC 8309, January 2018.
[RFC8466] G. Fioccola, ed., "A YANG Data Model for Layer 2 Virtual
Private Network (L2VPN) Service Delivery", RFC8466,
October 2018.
[TNBI] Busi, I., Daniel, K. et al., "Transport Northbound
Interface Applicability Statement", draft-ietf-ccamp-
transport-nbi-app-statement, work in progress.
[ACTN-VN] Y. Lee, et al., "A Yang Data Model for ACTN VN Operation",
draft-ietf-teas-actn-vn-yang, work in progress.
[TSM] Y. Lee, et al., "Traffic Engineering and Service Mapping Yang
Model", draft-ietf-teas-te-service-mapping-yang, work in
progress.
[ACTN-PM] Y. Lee, et al., "YANG models for VN & TE Performance
Monitoring Telemetry and Scaling Intent Autonomics",
draft-lee-teas-actn-pm-telemetry-autonomics, work in
progress.
[BGP-L3VPN] D. Jain, et al. "Yang Data Model for BGP/MPLS L3 VPNs",
draft-ietf-bess-l3vpn-yang, work in progress.
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Acknowledgments
This document was prepared using 2-Word-v2.0.template.dot.
Some of this analysis work was supported in part by the European
Commission funded H2020-ICT-2016-2 METRO-HAUL project (G.A. 761727).
Contributors
Sergio Belotti
Nokia
Email: sergio.belotti@nokia.com
Gabriele Galimberti
Cisco
Email: ggalimbe@cisco.com
Zheng Yanlei
China Unicom
Email: zhengyanlei@chinaunicom.cn
Anton Snitser
Sedona
Email: antons@sedonasys.com
Washington Costa Pereira Correia
TIM Brasil
Email: wcorreia@timbrasil.com.br
Peruzzini et al. Expires December 29, 2020 [Page 34]
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Michael Scharf
Hochschule Esslingen - University of Applied Sciences
Email: michael.scharf@hs-esslingen.de
Young Lee
Sung Kyun Kwan University
Email: younglee.tx@gmail.com
Jeff Tantsura
Apstra
Email: jefftant.ietf@gmail.com
Authors' Addresses
Fabio Peruzzini
TIM
Email: fabio.peruzzini@telecomitalia.it
Jean-Francois Bouquier
Vodafone
Email: jeff.bouquier@vodafone.com
Italo Busi
Huawei
Email: Italo.busi@huawei.com
Daniel King
Old Dog Consulting
Email: daniel@olddog.co.uk
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Daniele Ceccarelli
Ericsson
Email: daniele.ceccarelli@ericsson.com
Peruzzini et al. Expires December 29, 2020 [Page 36]
