Internet DRAFT - draft-zhang-ccamp-transport-yang-gap-analysis
draft-zhang-ccamp-transport-yang-gap-analysis
CCAMP Working Group X. Zhang, Ed.
Internet-Draft Huawei Technologies
Intended status: Informational A. Sharma, Ed.
Expires: May 4, 2017 Infinera
S. Belotti
Nokia
T. Cummings
Ericsson
October 31, 2016
YANG Models for the Northbound Interface of a Transport Network
Controller: Requirements and Gap Analysis
draft-zhang-ccamp-transport-yang-gap-analysis-01
Abstract
A transport network is a lower-layer network designed to provide
connectivity services for a higher-layer network to carry the traffic
opaquely across the lower-layer network resources. A transport
network may be constructed from equipment utilizing any of a number
of different transport technologies such as the optical transport
infrastructure (Synchronous Optical Networking (SONET) / Synchronous
Digital Hierarchy (SDH) and Optical Transport Network (OTN)) or
packet transport as epitomized by the MPLS Transport Profile (MPLS-
TP).
All transport networks have high benchmarks for reliability and
operational simplicity. This suggests a common, technology-
independent management/control paradigm that can be extended to
represent and configure specific technology attributes.
This document describes the high-level requirements facing transport
networks in order to provide open interfaces for resource
programmability and control/management automation. Furtheremore, gap
analysis against existing models are also provided so that it can
used as the guidance to separate efforts/drafts proposing new models
or augmentation models based on existing models.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
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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 May 4, 2017.
Copyright Notice
Copyright (c) 2016 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
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. High-level Modeling Requirements . . . . . . . . . . . . . . 5
3.1. Generic Requirements . . . . . . . . . . . . . . . . . . 5
3.2. Transport Network and TE Topology Requirements . . . . . 6
3.2.1. Topological Link Requirements . . . . . . . . . . . . 6
3.2.2. Topology Node Requirements . . . . . . . . . . . . . 6
3.2.3. Termination Point Requirements . . . . . . . . . . . 6
3.3. Transport Service Requirements . . . . . . . . . . . . . 7
3.4. Tunnel/LSP Requirements . . . . . . . . . . . . . . . . . 7
4. Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1. Single-domain Scenario . . . . . . . . . . . . . . . . . 7
4.2. Multi-domain Scenario . . . . . . . . . . . . . . . . . . 9
4.3. Multi-layer Scenario . . . . . . . . . . . . . . . . . . 11
4.4. Function Summary and Related YANG Models . . . . . . . . 11
5. Function Gap Analysis on YANG Model Level . . . . . . . . . . 12
5.1. Topology Related Functions . . . . . . . . . . . . . . . 12
5.1.1. Obtaining Access Point Info . . . . . . . . . . . . . 13
5.1.2. Obtaining Topology . . . . . . . . . . . . . . . . . 13
5.1.3. Virtual Network Operations . . . . . . . . . . . . . 13
5.2. Tunnel Operations . . . . . . . . . . . . . . . . . . . . 14
5.3. Service Requests . . . . . . . . . . . . . . . . . . . . 14
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
7. Security Considerations . . . . . . . . . . . . . . . . . . . 14
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8. Manageability Considerations . . . . . . . . . . . . . . . . 15
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15
10. Contributing Authors . . . . . . . . . . . . . . . . . . . . 15
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
11.1. Normative References . . . . . . . . . . . . . . . . . . 16
11.2. Informative References . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction
A transport network is a server-layer network designed to provide
connectivity services, or more advanced services like Virtual Private
Networks (VPN) for a client-layer network to carry the client traffic
opaquely across the server-layer network resources. It acts as a
pipe provider for upper-layer networks, such as IP network and mobile
networks.
Transport networks, such as Synchronous Optical Networking (SONET) /
Synchronous Digital Hierarchy (SDH), Optical Transport Network (OTN),
Wavelength Division Multiplexing (WDM), and flexi-grid networks, are
often built using equipments from a single vendor and are managed
using proprietary interfaces to dedicated Element Management Systems
(EMS) / Network Management Systems (NMS). All transport networks
have high benchmarks for reliability and operational simplicity.
This suggests a common, technology-independent management/control
paradigm that is extended to represent and configure specific
technology attributes.
Network providers need a common way to manage multi-vendor and multi-
domain transport networks (where each domain is an island of
equipments from a single supplier) and this requirement has been
further stressed by the expansion in network size. At the same time,
applications such as data center interconnection require larger and
more dynamic connectivities. Therefore, transport networks face new
challenges going beyond automatic provisioning of tunnel setup
enabled by GMPLS (Generalized Multi-Protocol Label Switching)
protocols to achieve automatic service provisioning, as well as
address opportunities enabled by partitioning the transport network
through the process of resource slicing. With a reduction in
operational expenditure (OPEX) and capital expenditure (CAPEX) as the
usual objectives, a common interface to transport network controllers
are considered by network providers as a way to meet the
requirements. The concept of Software Defined Networking (SDN)
leverages these ideas.
The YANG language [RFC6020] is currently the data modeling language
of choice within the IETF and has been adopted by a number of
industry-wide open management and control initiatives. YANG may be
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used to model both configuration and operational states; it is
vendor-neutral and supports extensible APIs for control and
management of elements.
This document first specifies the scope and provides high-level
requirements for transport network open interface modelling.
Furthermore, detailed gap analysis of the typical scenarios with the
existing model are provided. Thus, this document can used as a
reference of existing models, and provides information of the missing
ones which suggest further work.
2. Scope
For this draft, we use the domain controller as the reference point,
with South Bound Interface (SBI) to the transport devices and North
Bound Interface (NBI) to the orchestrator.
Transport networks have been evolving and deploying for decades,
making them very heterogeneous. New and legacy transport devices
support many protocols such as Path Computation Element Protocol
(PCEP), TL1, SNMP, CLI, XML, NETCONF, Openflow etc. Domain
controllers interfacing with transport devices need to support these
protocols on its SBI, making the southbound fragmented. Domain
controllers abstract the fragmented southbound view for its
northbound clients by normalizing the NBI across various
technologies, protocols, and vendors. The focus of this document is
not to go into various southbound protocols to interface with the
transport devices. Instead, this document focuses on the models that
can be used by the domain controller and the orchestrator for various
use cases identified in later sections of this document.
There is an ongoing unofficial weekly meeting among a group of
individuals (see the github files [Transport-modeling-github] for
more meeting minutes and materials produced), focusing on the efforts
of analyzing the IETF models against a list of well known use cases
to identify gaps. This document captures this efforts and summarized
the main work and key findings of this group work.
YANG models are currently developed not only in IETF, but also in
other Standard Development Organizations (SDO) such as ONF and MEF,
which can be used on the interfaces of a domain controller and an
orchestrator. Each domain controller and orchestrator can use models
developed by different SDOs. Therefore it is important to ensure
that deployment use cases and related funcionalities are supported by
all models to allow a seamless translation/mediation between systems
using different models.
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If the Abstraction and Control of Traffic-Engineered Networks (ACTN)
defined in [I-D.ceccarelli-teas-actn-framework] is used as a
reference architcture, then the focus is equivalent to MPI (MDSC-PNC
Interface) and CMI (CNC-MDSC Interface). More details about the
relationship of the type of models and the type of ACTN interfaces
can be found in [I-D.zhang-teas-actn-yang].
3. High-level Modeling Requirements
This section covers various high-level modeling requirements for
transport networks.
3.1. Generic Requirements
The following are generic requirements for transport models:
o User Intent: Transport models should maintain separation between
high level user intent and the operational state of the network.
For example, maintaining separation between user service request,
including all constraints, and the actual service and connection
state in the network.
o State Management: Network and service objects should support the
following states: administrative state, operational state, and
lifecycle state. Administrative state and operational states are
well understood. Lifecycle state is defined in the ONF and it is
used to track the planned deployment allocation of the related
entity in the model as well as withdrawal of resources. Here the
lifecylce state includes planned state, potential state, installed
state, and pending removal state.
o Identifiers: Network and service objects should support the
following identifier:
* ID: A unique entity ID provided by the controller. The
identifier SHOULD be chosen such that the same entity in a real
network topology will always be identified through the same ID,
even if the model is instantiated in separate datastores.
Controller may choose to capture semantics in the identifier,
for example to indicate the type of entity and/or the type of
the parent identity.
* Name: A unique name provided by the client for the entity. The
name can be modified, if required, by the client.
* User Labels: A list of freeform strings that can be used as
alias for the entity by the client. Multiple user labels are
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permitted for the entity, and client can edit these user
labels. User labels do not need to be unique.
3.2. Transport Network and TE Topology Requirements
3.2.1. Topological Link Requirements
The model should support the following Topological Links:
o Physical Links
o Abstract Links [RFC7926]
o Compound Link which are are internally aggregated lower level
links
o Access Links which connect the router port to the client port of
the transport system
o Transitional Links which provide adaptation capability between
layers within a network element
The Link should support various link related attributes like cost,
latency, capacity, risk characteristics (including shared risk). The
model should provide clear association between Link and its topology
(including virtual topology), nodes and termination points.
The model should provide association between the link and any
underlay circuit / service supporting the Link.
3.2.2. Topology Node Requirements
The model should support the following Topology Node:
o Physical Node
o Abstract Node
o Chassis / Forwarding Domain
[Editors' note: more details will be added later, which can be found
in [Transport-requirements-github].]
3.2.3. Termination Point Requirements
[Editors' note: this will be added later, which can be found in
[Transport-requirements-github].]
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3.3. Transport Service Requirements
[Editors' note: this will be added later, which can be found in
[Transport-requirements-github].]
3.4. Tunnel/LSP Requirements
[Editors' note: this will be added later which can be found in
[Transport-requirements-github].]
4. Scenarios
There are several scenarios (a.k.a., use cases) where an open
interface via domain controller to access server-layer (transport)
network resources would be useful. Three scenarios are provided and
can be used for model instantiation exercise to identify missing
pieces of existing models. Note the models provided in this draft is
for explanation purpose, the group effort actually uses slight
different network examples for gap analysis exercise (see
[Transport-usecases-github] for more details).
4.1. Single-domain Scenario
The first scenario is depicted as below (Figure 1 ):
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/--\ +------+ +------+ /--\
| 1 ~~~| A +------------------| B |~~~~~ 3 |
\--/ +-----++ +--+---+ \--/
| |
| |
| |
++-----+ +---+--+
| F +------------+ C |
++-----+ +--+---+
| |
| |
| |
| |
| |
+---+-+ +---+-+ /---\
| E +---------------+ D |~~~~ 4 |
/--\~~~~~+-----+ +-----+ \---/
| 2 |
\--/
+----+ /--\
| | Transport NE | | DC
+----+ \--/
----- Transport Link ~~~ Transport-DC link
(a) Data Centers interconnected via a transport network
+---------------------+
| Data Center Network |
| Controller |
+---------+-----------+
|
|
|
| Open Interface
|
|
+---------+-----------+
| Transport Network |
| Controller |
+---------------------+
(b) The controller architecture for data center interconnection
Figure 1: Scenario 1: Data centers interconnected via a transport
network and the controller architecture
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For the data center operator, as a client of the transport network,
assuming the objective is to trigger the transport network to provide
connectivity on demand, the following capabilities, at a minimum,
would be required on the common interface between the two controllers
illustrated in Figure 1:
o The ability to obtain information about a set of access points of
the transport network, including information such as access point
identifiers, capabilities, etc.; for instance, transport-network-
side end point identifiers related to the access link between DC1
and Transport NE A.
o The capability to send a request for a service using the
aforementioned access point information, as well as the ability to
retrieve a list of service requests and their status. In this
request, it should at least be possible to include source node,
destination node, and requested bandwidth to request the transport
network to set up tunnels/paths so as to provide the requested
connectivity for the service request.
o Note that in this case, the acquisition of the topology, be it
physical or logical, of the transport network is not a compulsory
requirement, but it may indeed be able to give data center
providers more control over the transport resource usage.
Furthermore, the client controller can impose a virtual network of
its own choice by requesting a slice of network resource with its
choice of network parameters (such as network topology type,
bandwidth etc.).
4.2. Multi-domain Scenario
The second scenario, more complicated than the first, is depicted as
below (Figure 2). In this example, we focus on the management and
control via common interfaces for multi-domain networks with
homogeneous technologies (such as OTN), but it can be extended
further to multi-domain networks with heterogeneous technologies with
higher complexity.
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+-------------------------------------------------+
| Orchestrator/Coordinator |
+---------+--------------+-------------------+----+
| | |
| | |
+------------+--+ | +----------+----------+
| Controller 1 | | | Controller 2 |
+---------+-----+ | +-------+-------------+
# +----------------+ #
#Qx | Controller 3 | #
# +----------------+ #TL1
# # #
----+----- # ----+-----
____/ \____ # ____/ \____
| | # | |
| | # | |
| Network Domain +***********+ Network Domain |
| 1 | # | 2 |
|____ ___| # |____ ___|
\ / #PCEP \ /
----------- # *----------
* * # * *
* * # * *
* * # * *
* * # * *
* * # * *
* * # * *
* *----+-----* *
* ____/ \____ *
*| |*
| |
| Network Domain |
| 3 |
|____ ___|
\ /
----------
***** inter-domain links
----- Open Interfaces
##### Controller-device interfaces
Figure 2: Scenario 2: Multi-domain network control and management
For the second scenario, the orchestrator controls and manages three
distinct network domains, each controlled/managed by their domain
controller. This scenario is of interest not only to transport-only
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networks, but also to heretegenous network orchestration such as
coordinating the transport, the radio (5G) and packet core domains.
But to keep the functions explanation later accurate, only transport-
only multi-domain networks are considered.
In order to orchestrate across domains/layers, besides the
capabilities mentioned for the first scenario, the orchestrator needs
its interface between domain controllers to be equipped with the
following additional functions:
o Access to the topologies reported by each domain controller,
including cross-domain links for the purpose of planning and
requesting the paths of end-to-end tunnels. Depending on the
abstraction level of the reported topology, the orchestrator has
different control granularities.
o Alterntively, the capability for the orchestrator to request "path
computation" to a domain controller in order to create an end-to-
end tunnel stitched together by different connection contribution
obtained by consulting to each domain controller.
o The ability to set up, delete and modify tunnels, be it within one
domain or across multiple domains. Furthermore, it should have
the abilty to view the tunnels created within each domain as well
as those that cross domains as reported by each domain controller.
4.3. Multi-layer Scenario
In the first use case, if there are multiple technologies invovled,
then it can be considered as a multi-layer case. [Editors' note:
more details to be added later, some can be found in
[Transport-usecases-github].]
4.4. Function Summary and Related YANG Models
For the common interface of a transport controller towards a
northbound client, six main functions are derived from the scenarios
explained in the last section. They are summarized in the table
below and we also match these functions with YANG models that are
being developed in existing drafts.
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+-------------+-----------------------+---------------------------+
| Functions | Description | Related Existing |
| | | YANG Models |
|-------------+-----------------------+---------------------------+
| Obtaining |Getting the necessary | ietf-network.yang |
| Access |access points info | ietf-network-topology.yang|
| Point Info | | ietf-te-topology.yang |
+-------------+-----------------------+---------------------------+
| Obtaining |Getting the topology | ietf-te-topology.yang |
| Topology |info | ietf-otn-topology.yang |
| | | ietf-wson-topology.yang |
+-------------+-----------------------+---------------------------+
| Tunnel |Tunnel Setup, Deletion | |
| Operations |Modification and Info | ietf-te.yang |
| |Retrieval | ietf-otn-tunnel.yang |
+-------------+-----------------------+---------------------------+
| Service |Requesting connectivity| |
| Request |service and retrieval |ietf-transport-service.yang|
| |the list of service | ietf-actn-vn.yang |
| |request | |
+-------------+-----------------------+---------------------------+
|Path Comp. | Path Computation pre | |
| | service provisioning | ietf-te.yang |
+-------------+-----------------------+---------------------------+
| Virtual |Requesting a virtual | |
| Network |network and related | ietf-te-topology.yang |
| Operations |control operations, | ietf-actn-vn.yang |
| |(e.g.,update, deletion)| |
+-------------+-----------------------+---------------------------+
Analysis and descriptions of whether and how these functions are
supported by the YANG models are provided in more detail in
Section 5.
5. Function Gap Analysis on YANG Model Level
5.1. Topology Related Functions
As shown in the previous section, the functions of obtaining access
point information, obtaining topology, and imposing virtual network
operations can take advantages of the same set of topology YANG
models. These functions are briefly explained further in the
following sub-sections.
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5.1.1. Obtaining Access Point Info
For cases such as scenario 1, a client may have no interest in
directly controlling network resources, but might want an automated
common control interface for initiating service requests. In this
case, a transport domain controller may provide the access point
information. This information can then be used in service request
sent over the common interface.
The TE Topology YANG model provided in [TE-topo]
[I-D.ietf-teas-yang-te-topo] can be used to provide a list of links.
If the remote node and termination point information is unknown, it
is omitted from the reported information. If the client-side node
and termination point information is obtained via configuration or a
distributed discovery mechanism, then it can also be added into the
reported information. Technology-specific details might also be
needed to further express the constraints/attributes associated with
the access points. Note that all of this information is usually read
only.
5.1.2. Obtaining Topology
Refer to [I-D.ietf-teas-yang-te-topo] for explanations and examples
on how to obtain the topology. For technology specific topology
information, other models such as those provided in [WDM-Topo]
[I-D.ietf-ccamp-wson-yang] and [ODU-Topo]
[I-D.zhang-ccamp-l1-topo-yang] may be used.
There are two ways provided in [I-D.ietf-teas-yang-te-topo] in terms
of how to present a multi-layer topology, discussions have been
carried out among the unofficial group in terms of how the
transitional link approach can work and the discussion material will
be available soon in the github [Transport-modeling-github].
5.1.3. Virtual Network Operations
There are two ways to request the creation of a virtual network. One
is to define the topology explicitly using the model provided in the
topology YANG drafts listed in previous section. The other way is to
provide an estimated traffic information (a traffic matrix) and ask
for a domain controller of the provider network to provide a virtual
network that can fulfill the demand. This second approach is
supported by the YANG model in [I-D.lee-teas-actn-vn-yang].
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5.2. Tunnel Operations
The current [TE-Tunnel] [I-D.ietf-teas-yang-te] provides a technology
agnostic Traffic-Engineered (TE) to manage and configure tunnel. The
model included in that draft is currently being developed to make it
generic for both controller and device usage. In the latest version,
it already provides such a generic TE tunnel model that can cater to
the base requirementss for tunnel operations but it may need to be
augmented to support controller-specific operations.
Furthermore, technology-specific augmentations of the base generic TE
tunnel models are needed. For example, for Optical Channel (OCh)
(note: ITU is updating this term as OTSi.) tunnels in WDM networks,
information such as the lambda resource usage is needed. Similarly,
for ODU tunnels, information such as ODU-specific client signal,
tributary slot information etc. is needed.
For path computation, [I-D.busibel-teas-yang-path-computation]
presents now only use cases but YANG model work is also under
consideration to provide statelss path computation RPC. There is
currently ongoing discussions on how to provide such a function using
the TE tunnel model defined in [I-D.ietf-teas-yang-te] as a base.
5.3. Service Requests
Service model is an important type of models, such as the one
provided in [I-D.zhang-teas-transport-service-model], that enables
automated operations between a client controller or an orchestrator
and a domain controller. This transport connectivity service model
is different from the model of a tunnel since the transport
connectivity service model are enforced over the client-server
interfaces, and it hides unnecessary provider network details from a
client.
6. IANA Considerations
This document requests no IANA actions.
7. Security Considerations
Clearly modifying server-layer resources will have a significant
impact on network infrastructure. More specifically they will
provide the services and applications running across client-layers,
which the server-layer is supporting. Therefore, security must be an
important consideration when implementing the architecture, models
and protocol mechanisms discussed in this document.
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Communicating service and network information (including access point
identifiers, capabilities, topologies, etc.) across external
interfaces represents a security risk. Thus, mechanisms to encrypt
or preserve the domain topology confidentiality should be used.
A key consideration are the external protocols (those shown as
entering or leaving the orchestrator and controllers shown in
Figure 2 (Scenario 2: Multi-domain network control and management))
which must be appropriately secured. This security should include
authentication and authorization to control access to different
functions that the orchestrator may perform to modify or create state
in the server-layer, and the establishment and management of the
orchestrator to controller relationship.
The orchestrator will contain significant data about the network
domains, the services carried by each domain, and customer type
information. Therefore, access to information held in the
orchestrator must be secured. Since such access will be largely
through external mechanisms, it may be pertinent to apply policy-
based controls to restrict access and functions.
8. Manageability Considerations
The core objectives of this document are to assist in the deployment
and operation of transport services across server-layer network
infrastructure. The model-driven management/control principles,
which are vendor-neutral and supported by extensible APIs, should be
utilized.
The open models described in this document are based on YANG
[RFC6020] and the RESTCONF [RESTCONF] messaging protocol, a REST-like
protocol running over HTTP for accessing data defined in YANG, may
also be used.
9. Acknowledgements
We would like to thank Young Lee, Igor Bryskin and Aihua Guo for
their comments and discussions.
10. Contributing Authors
The following people all contributed to this document and are listed
below:
Ruiquan Jing
China Telecom
Email: jingrq@ctbri.com.cn
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Yan Shi
China Unicom
Email: shiyan49@chinaunicom.cn
Jeong-dong Ryoo
ETRI
Email: ryoo@etri.re.kr
Yunbin Xu
CAICT
Email: xuyunbin@ritt.cn
Daniel King
Lancaster University
Email: d.king@lancaster.ac.uk
11. References
11.1. Normative References
[I-D.ietf-netconf-restconf]
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", draft-ietf-netconf-restconf-13 (work in
progress), April 2016.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<http://www.rfc-editor.org/info/rfc6020>.
11.2. Informative References
[I-D.busibel-teas-yang-path-computation]
Busi, I., Belotti, S., Lopezalvarez, V., Dios, O.,
ansharma@infinera.com, a., Shi, Y., Vilata, R., and K.
Sethuraman, "Yang model for requesting Path Computation",
draft-busibel-teas-yang-path-computation-00 (work in
progress), October 2016.
[I-D.ceccarelli-teas-actn-framework]
Ceccarelli, D. and Y. Lee, "Framework for Abstraction and
Control of Traffic Engineered Networks", draft-ceccarelli-
teas-actn-framework-02 (work in progress), April 2016.
Zhang, et al. Expires May 4, 2017 [Page 16]
Internet-Draft Transport NBI Gap Analysis October 2016
[I-D.ietf-ccamp-wson-yang]
Lee, Y., Dhody, D., Zhang, X., Guo, A., Lopezalvarez, V.,
King, D., and B. Yoon, "A Yang Data Model for WSON Optical
Networks", draft-ietf-ccamp-wson-yang-01 (work in
progress), April 2016.
[I-D.ietf-teas-yang-te]
Saad, T., Gandhi, R., Liu, X., Beeram, V., Shah, H., Chen,
X., Jones, R., and B. Wen, "A YANG Data Model for Traffic
Engineering Tunnels and Interfaces", draft-ietf-teas-yang-
te-02 (work in progress), October 2015.
[I-D.ietf-teas-yang-te-topo]
Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
O. Dios, "YANG Data Model for TE Topologies", draft-ietf-
teas-yang-te-topo-04 (work in progress), March 2016.
[I-D.lee-teas-actn-vn-yang]
Lee, Y., Ceccarelli, D., Miyasaka, T., Park, P., and B.
Yoon, "A Yang Data Model for ACTN VN Operation", draft-
lee-teas-actn-vn-yang-01 (work in progress), July 2016.
[I-D.zhang-ccamp-l1-topo-yang]
Zhang, X., Rao, B., and X. Liu, "A YANG Data Model for
Layer 1 Network Topology", draft-zhang-ccamp-l1-topo-
yang-01 (work in progress), December 2015.
[I-D.zhang-teas-actn-yang]
Lee, Y., Zhang, X., Yoon, B., and O. Dios, "Applicability
of YANG models for Abstraction and Control of Traffic
Engineered Networks", draft-zhang-teas-actn-yang-01 (work
in progress), October 2016.
[I-D.zhang-teas-transport-service-model]
Zhang, X. and J. Ryoo, "A Service YANG Model for
Connection-oriented Transport Networks", draft-zhang-teas-
transport-service-model-00 (work in progress), July 2016.
[RFC7926] Farrel, A., Ed., Drake, J., Bitar, N., Swallow, G.,
Ceccarelli, D., and X. Zhang, "Problem Statement and
Architecture for Information Exchange between
Interconnected Traffic-Engineered Networks", BCP 206,
RFC 7926, DOI 10.17487/RFC7926, July 2016,
<http://www.rfc-editor.org/info/rfc7926>.
[Transport-modeling-github]
"https://github.com/TransportModels/IETF-Transport-
Modeling", IETF-Transport-Modeling-GITHUB , October 2016.
Zhang, et al. Expires May 4, 2017 [Page 17]
Internet-Draft Transport NBI Gap Analysis October 2016
[Transport-requirements-github]
"https://github.com/TransportModels/IETF-Transport-
Modeling/tree/master/Transport-Requirements", IETF-
Transport-Modeling-GITHUB , October 2016.
[Transport-usecases-github]
"https://github.com/TransportModels/IETF-Transport-
Modeling/tree/master/Transport-UseCases", IETF-Transport-
Modeling-GITHUB , October 2016.
Authors' Addresses
Xian Zhang (editor)
Huawei Technologies
F3-5-B R&D Center, Huawei Industrial Base, Bantian, Longgang District
Shenzhen, Guangdong 518129
P.R.China
Email: zhang.xian@huawei.com
Anurag Sharma (editor)
Infinera
US
Email: ansharma@infinera.com
Sergio Belotti
Nokia
Italy
Email: sergio.belotti@nokia.com
Tara Cummings
Ericsson
Email: tara.cummings@ericsson.com
Zhang, et al. Expires May 4, 2017 [Page 18]
