Yang model for requesting Path Computation
draft-busibel-teas-yang-path-computation-00
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| Authors | Italo Busi , Sergio Belotti , Victor Lopez , Oscar Gonzalez de Dios , ansharma@infinera.com , Yan Shi , Ricard Vilalta , Karthik Sethuraman | ||
| Last updated | 2016-10-28 | ||
| Replaced by | draft-ietf-teas-yang-path-computation, draft-ietf-teas-yang-path-computation, draft-ietf-teas-yang-path-computation | ||
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draft-busibel-teas-yang-path-computation-00
TEAS Working Group Italo Busi
Internet Draft Huawei
Intended status: Informational Sergio Belotti
Expires: April 2017 Nokia
Victor Lopez
Oscar Gonzalez de Dios
Telefonica
Anurag Sharma
Infinera
Yan Shi
China Unicom
Ricard Vilalta
CTTC
Karthik Sethuraman
NEC
October 28, 2016
Yang model for requesting Path Computation
draft-busibel-teas-yang-path-computation-00.txt
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Abstract
There are scenarios, typically in a hierarchical SDN context, in
which an orchestrator may not have detailed information to be able
to perform an end-to-end path computation and would need to request
lower layer/domain controllers to calculate some (partial) feasible
paths.
Multiple protocol solutions can be used for communication between
different controller hierarchical levels. This document assumes that
the controllers are communicating using YANG-based protocols (e.g.,
NETCONF or RESTCONF).
This document describes some use cases for a YANG model to request
path computation.
Table of Contents
1. Introduction...................................................3
2. Use Cases......................................................4
2.1. IP-Optical integration....................................4
2.1.1. Inter-layer path computation.........................6
2.1.2. Route Diverse IP Services............................8
2.2. Multi-domain TE Networks..................................8
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2.3. Data center interconnections..............................9
3. Interactions with TE Topology.................................11
3.1. TE Topology Aggregation using the "virtual link model"...11
3.2. TE Topology Abstraction..................................14
3.3. Complementary use of TE topology and path computation....15
4. Motivation for a YANG Model...................................17
4.1. Benefits of common data models...........................17
4.2. Benefits of a single interface...........................18
4.3. Extensibility............................................19
5. Path Optimization Request.....................................19
6. YANG Model for requesting Path Computation....................19
7. Security Considerations.......................................20
8. IANA Considerations...........................................20
9. References....................................................20
9.1. Normative References.....................................20
9.2. Informative References...................................20
10. Acknowledgments..............................................21
1. Introduction
There are scenarios, typically in a hierarchical SDN context, in
which an orchestrator may not have detailed information to be able
to perform an end-to-end path computation and would need to request
lower layer/domain controllers to calculate some (partial) feasible
paths.
When we are thinking to this type of scenarios we have in mind
specific level of interfaces on which this request can be applied.
We can reference ABNO Control Interface [RFC7491] in which an
Application Service Coordinator can request ABNO controller to take
in charge path calculation (see Figure 1 in the RFC) and/or ACTN
[ACTN-frame],where controller hierarchy is defined, the need for
path computation arises on both interfaces CMI (interface between
Customer Network Controller(CNC) and Multi Domain Service
Coordinator (MDSC)) and/or MPI (interface between MSDC-PNC).[ACTN-
Info] describes an information model for the Path Computation
request.
Multiple protocol solutions can be used for communication between
different controller hierarchical levels. This document assumes that
the controllers are communicating using YANG-based protocols (e.g.,
NETCONF or RESTCONF).
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Path Computation Elements, Controllers and Orchestrators perform
their operations based on Traffic Engineering Databases (TED). Such
TEDs can be described, in a technology agnostic way, with the YANG
Data Model for TE Topologies [TE-TOPO]. Furthermore, the technology
specific details of the TED are modeled in the augmented TE topology
models (e.g. [L1-TOPO] for Layer-1 ODU technologies).
The availability of such topology models allows providing the TED
using YANG-based protocols (e.g., NETCONF or RESTCONF). Furthermore,
it enables a PCE/Controller performing the necessary abstractions or
modifications and offering this customized topology to another
PCE/Controller or high level orchestrator.
The tunnels that can be provided over the networks described with
the topology models can be also set-up, deleted and modified via
YANG-based protocols (e.g., NETCONF or RESTCONF)using the TE-Tunnel
Yang model [TE-TUNNEL].
This document describes some use cases where a path computation
request, via YANG-based protocols (e.g., NETCONF or RESTCONF), can
be needed.
2. Use Cases
This section presents different use cases, where an orchestrator
needs to request underlying SDN controllers for path computation.
The presented uses cases have been grouped, depending on the
different underlying topologies: a) IP-Optical integration; b)
Multi-domain Traffic Engineered (TE) Networks; and c) Data center
interconnections.
2.1. IP-Optical integration
In these use cases, an Optical domain is used to provide
connectivity between IP routers which are connected with the Optical
domains using access links (see Figure 1).
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Figure 1 - IP+Optical Use Cases
It is assumed that the Optical domain controller provides to the
orchestrator an abstracted view of the Optical network. A possible
abstraction shall be representing the optical domain as one "virtual
node" with "virtual ports" connected to the access links.
The path computation request helps the orchestrator to know which
are the real connections that can be provided at the optical domain.
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Figure 2 - IP+Optical Topology Abstraction
2.1.1. Inter-layer path computation
In this use case, the orchestrator needs to setup an optimal path
between two IP routers R1 and R2.
As depicted in Figure 2, the Orchestrator has only an "abstracted
view" of the physical network, and it does not know the feasibility
or the cost of the possible optical paths (e.g., VP1-VP4 and VP2-
VP5), which depend from the current status of the physical resources
within the optical network and on vendor-specific optical
attributes.
The orchestrator can request the underlying Optical domain
controller to compute a set of potential optimal paths, taking into
account optical constraints. Then, based on its own constraints,
policy and knowledge (e.g. cost of the access links), it can choose
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which one of these potential paths to use to setup the optimal e2e
path crossing optical network.
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Figure 3 - IP+Optical Path Computation Example
For example, in Figure 3, the Orchestrator can request the Optical
domain controller to compute the paths between VP1-VP4 and VP2-VP5
and then decide to setup the optimal end-to-end path using the VP2-
VP5 Optical path even this is not the optimal path from the Optical
domain perspective.
Considering the dynamicity of the connectivity constraints of an
Optical domain, it is possible that a path computed by the Optical
domain controller when requested by the Orchestrator is no longer
valid when the Orchestrator requests it to be setup up.
It is worth noting that with the approach proposed in this document,
the likelihood for this issue to happen can be quite small since the
time window between the path computation request and the path setup
request should be quite short (especially if compared with the time
that would be needed to update the information of a very detailed
abstract connectivity matrix).
If this risk is still not acceptable, the Orchestrator may also
optionally request the Optical domain controller not only to compute
the path but also to keep track of its resources (e.g., these
resources can be reserved to avoid being used by any other
connection). In this case, some mechanism (e.g., a timeout) needs to
be defined to avoid having stranded resources within the Optical
domain.
These issues and solutions can be fine-tuned during the design of
the YANG model for requesting Path Computation.
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2.1.2. Route Diverse IP Services
This is for further study.
2.2. Multi-domain TE Networks
In this use case there are two TE domains which are interconnected
together by multiple inter-domains links.
A possible example could be a multi-domain optical network.
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Figure 4 - Multi-domain multi-link interconnection
In order to setup an end-to-end multi-domain TEpath (e.g., between
nodes A and H), the orchestrator needs to know the feasibility or
the cost of the possible TE paths within the two TE domains, which
depend from the current status of the physical resources within each
TE network. This is more challenging in case of optical networks
because the optimal paths depend also on vendor-specific optical
attributes (which may be different in the two domains if they are
provided by different vendors).
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In order to setup a multi-domain TE path (e.g., between nodes A and
H), Orchestrator can request the TE domain controllers to compute a
set of intra-domain optimal paths and take decisions based on the
information received. For example:
o The Orchestrator asks TE domain controllers to provide set of
paths between A-C, A-D, E-H and F-H
o TE domain controllers return a set of feasible paths with the
associated costs: the path A-C is not part of this set(in optical
networks, it is typical to have some paths not being feasible due
to optical constraints that are known only by the optical domain
controller)
o The Orchestrator will select the path A- D-F- H since it is the
only feasible multi-domain path and then request the TE domain
controllers to setup the A-D and F-H intra-domain paths
o If there are multiple feasible paths, the Orchestrator can select
the optimal path knowing the cost of the intra-domain paths
(provided by the TE domain controllers) and the cost of the
inter-domain links (known by the Orchestrator)
This approach may have some scalability issues when the number of TE
domains is quite big (e.g. 20).
In this case, it would be worthwhile using the abstract TE topology
information provided by the domain controllers to limit the number of
potential optimal end-to-end paths and then request path computation
to fewer domain controllers in order to decide what the optimal path
within this limited set is.
For more details, see section 3.3.
2.3. Data center interconnections
In these use case, there is an TE domain which is used to provide
connectivity between data centers which are connected with the TE
domain using access links.
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Figure 5 - Data Center Interconnection Use Case
In this use case, a virtual machine within Data Center 1 (DC1) needs
to transfer data to another virtual machine that can reside either
in DC2 or in DC3.
The optimal decision depends both on the cost of the TE path (DC1-
DC2 or DC1-DC3) and of the computing power (data center resources)
within DC2 or DC3.
The Cloud Orchestrator may not be able to make this decision because
it has only an abstract view of the TE network (as in use case in
2.1).
The cloud orchestrator can request to the TE domain controller to
compute the cost of the possible TE paths (e.g., DC1-DC2 and DC1-
DC3) and to the DC controller to compute the cost of the computing
power (DC resources) within DC2 and DC3 and then it can take the
decision about the optimal solution based on this information and
its policy.
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3. Interactions with TE Topology
The use cases described in section 2 have been described assuming
that the topology view exported by each underlying SDN controller to
the orchestrator is aggregated using the "virtual node model",
defined in [RFC7926].
TE Topology information, e.g., as provided by [TE-TOPO], could in
theory be used by an underlying SDN controllers to provide TE
information to the orchestrator thus allowing the Path Computation
Element (PCE) within the Orchestrator to perform multi-domain path
computation by its own, without requesting path computations to the
underlying SDN controllers.
This section analyzes the need for an orchestrator to request
underlying SDN controllers for path computation even in these
scenarios as well as how the TE Topology information and the path
computation can be complementary.
In nutshell, there is a scalability trade-off between providing all
the TE information needed by the Orchestrator's PCE to take optimal
path computation decisions by its own versus requesting the
Orchestrator to ask to too many underlying SDN Domain Controllers a
set of feasible optimal intra-domain TE paths.
3.1. TE Topology Aggregation using the "virtual link model"
Using the TE Topology model, as defined in [TE-TOPO], the underlying
SDN controller can export the whole TE domain as a single abstract
TE node with a "detailed connectivity matrix", which extends the
"connectivity matrix", defined in [RFC7446], with specific TE
attributes (e.g., delay, SRLGs and summary TE metrics).
The information provided by the "detailed abstract connectivity
matrix" would be equivalent to the information that should be
provided by "virtual link model" as defined in [RFC 7926].
For example, in the IP-Optical integration use case, described in
section 2.1, the Optical domain controller can make the information
shown in Figure 3 available to the Orchestrator as part of the TE
Topology information and the Orchestrator could use this information
to calculate by its own the optimal path between routers R1 and R2,
without requesting any additional information to the Optical Domain
Controller.
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However, there is a tradeoff between the accuracy (i.e., providing
"all" the information that might be needed by the Orchestrator's
PCE) and scalability to be considered when designing the amount of
information to provide within the "detailed abstract connectivity
matrix".
Figure 6 below shows another example, similar to Figure 3, where
there are two possible Optical paths between VP1 and VP4 with
different properties (e.g., available bandwidth and cost).
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Figure 6 - IP+Optical Path Computation Example with multiple choices
Reporting all the information, as in Figure 6, using the "detailed
abstract connectivity matrix", is quite challenging from a
scalability perspective. The amount of this information is not just
based on number of end points (which would scale as N-square), but
also on many other parameters, including client rate, user
constraints / policies for the service, e.g. max latency < N ms, max
cost, etc., exclusion policies to route around busy links, min OSNR
margin, max preFEC BER etc. All these constraints could be different
based on connectivity requirements.
It is also worth noting that the "connectivity matrix" has been
originally defined in WSON, [RFC7446] to report the connectivity
constrains of a physical node within the WDM network: the
information it contains is pretty "static" and therefore, once taken
and stored in the TE data base, it can be always being considered
valid and up-to-date in path computation request.
Using the "connectivity matrix" with an abstract node to abstract
the information regarding the connectivity constraints of an Optical
domain, would make this information more "dynamic" since the
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connectivity constraints of an Optical domain can change over time
because some optical paths that are feasible at a given time may
become unfeasible at a later time when e.g., another optical path is
established. The information in the "detailed abstract connectivity
matrix" is even more dynamic since the establishment of another
optical path may change some of the parameters (e.g., delay or
available bandwidth) in the "detailed abstract connectivity matrix"
while not changing the feasibility of the path.
"Connectivity matrix" is sometimes confused with optical reach table
that contain multiple (e.g. k-shortest) regen-free reachable paths
for every A-Z node combination in the network. Optical reach tables
can be calculated offline, utilizing vendor optical design and
planning tools,and periodically uploaded to the Controller: these
optical path reach tables are fairly static. However, to get the
connectivity matrix, between any two sites, either a regen free path
can be used, if one is available, or multiple regen free paths are
concatenated to get from src to dest, which can be a very large
combination. Additionally, when the optical path within optical
domain needs to be computed, it can result in different paths based
on input objective, constraints, and network conditions. In summary,
even though "optical reachability table" is fairly static, which
regen free paths to build the connectivity matrix between any source
and destination is very dynamic, and is done using very
sophisticated routing algorithms.
There is therefore the need to keep the information in the
"connectivity matrix" updated which means that there another
tradeoff between the accuracy (i.e., providing "all" the information
that might be needed by the Orchestrator's PCE) and having up-to-
date information. The more the information is provided and the
longer it takes to keep it up-to-date which increases the likelihood
that the Orchestrator's PCE computes paths using not updated
information.
It seems therefore quite challenging to have a "detailed abstract
connectivity matrix" that provides accurate, scalable and updated
information to allow the Orchestrator's PCE to take optimal
decisions by its own.
If the information in the "detailed abstract connectivity matrix" is
not complete/accurate, we can have the following drawbacks
considering for example the case in Figure 6:
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o If only the VP1-VP4 path with available bandwidth of 2 Gb/s and
cost 50 is reported, the Orchestrator's PCE will fail to compute
a 5 Gb/s path between routers R1 and R2, although this would be
feasible;
o If only the VP1-VP4 path with available bandwidth of 10 Gb/s and
cost 60 is reported, the Orchestrator's PCE will compute, as
optimal, the 1 Gb/s path between R1 and R2 going through the VP2-
VP5 path within the Optical domain while the optimal path would
actually be the one going thought the VP1-VP4 sub-path (with cost
50) within the Optical domain.
Instead, using the approach proposed in this document, the
Orchestrator, when it needs to setup an end-to-end path, it can
request the Optical domain controller to compute a set of optimal
paths (e.g., for VP1-VP4 and VP2-VP5) and take decisions based on
the information received:
o When setting up a 5 Gb/s path between routers R1 and R2, the
Optical domain controller may report only the VP1-VP4 path as the
only feasible path: the Orchestrator can successfully setup the
end-to-end path passing though this Optical path;
o When setting up a 1 Gb/s path between routers R1 and R2, the
Optical domain controller (knowing that the path requires only 1
Gb/s) can report both the VP1-VP4 path, with cost 50, and the
VP2-VP5 path, with cost 65. The Orchestrator can then compute the
optimal path which is passing thought the VP1-VP4 sub-path (with
cost 50) within the Optical domain.
3.2. TE Topology Abstraction
Using the TE Topology model, as defined in [TE-TOPO], the underlying
SDN controller can export an abstract TE Topology, composed by a set
of TE nodes and TE links, which are abstracting the topology
controlled by each domain controller.
Considering the example in Figure 4, the TE domain controller 1 can
export a TE Topology encompassing the TE nodes A, B, C and D and the
TE Link interconnecting them. In a similar way, TE domain controller
2 can export a TE Topology encompassing the TE nodes E, F, G and H
and the TE Link interconnecting them.
In this example, for simplicity reasons, each abstract TE node maps
with each physical node, but this is not necessary.
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In order to setup a multi-domain TE path (e.g., between nodes A and
H), the Orchestrator can compute by its own an optimal end-to-end
path based on the abstract TE topology information provided by the
domain controllers. For example:
o Orchestrator's PCE, based on its own information, can compute the
optimal multi-domain path being A-B-C-E-G-H, and then request the
TE domain controllers to setup the A-B-C and E-G-H intra-domain
paths
o But, during path setup, the domain controller may find out that
A-B-C intra-domain path is not feasible (as discussed in section
2.2, in optical networks it is typical to have some paths not
being feasible due to optical constraints that are known only by
the optical domain controller), while only the path A-B-D is
feasible
o So what the hierarchical controller computed is not good and need
to re-start the path computation from scratch
As discussed in section 3.1, providing more extensive abstract
information from the TE domain controllers to the multi-domain
Orchestator may lead to scalability problems.
In a sense this is similar to the problem of routing and wavelength
assignment within an Optical domain. It is possible to do first
routing (step 1) and then wavelength assignment (step 2), but the
chances of ending up with a good path is low. Alternatively, it is
possible to do combined routing and wavelength assignment, which is
known to be a more optimal and effective way for Optical path setup.
Similarly, it is possible to first compute an abstract end-to-end
path within the multi-domain Orchestrator (step 1) and then compute
an intra-domain path within each Optical domain (step 2), but there
are more chances not to find a path or to get a suboptimal path that
performing per-domain path computation and then stitch them.
3.3. Complementary use of TE topology and path computation
As discussed in section 2.2, there are some scalability issues with
path computation requests in a multi-domain TE network with many TE
domains, in terms of the number of requests to send to the TE domain
controllers. It would therefore be worthwhile using the TE topology
information provided by the domain controllers to limit the number
of requests.
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An example can be described considering the multi-domain abstract
topology shown in Figure 7. In this example, an end-to-end TE path
between domains A and F needs to be setup. The transit domain should
be selected between domains B, C, D and E.
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Figure 7 - Multi-domain with many domains (Topology information)
The actual cost of each intra-domain path is not known a priori from
the abstract topology information. The Orchestrator only knows, from
the TE topology provided by the underlying domain controllers, the
feasibility of some intra-domain paths and some upper-bound and/or
lower-bound cost information. With this information, together with
the cost of inter-domain links, the Orchestrator can understand by
its own that:
o Domain B cannot be selected as the path connecting domains A and
E is not feasible;
o Domain E cannot be selected as a transit domain since it is know
from the abstract topology information provided by domain
controllers that the cost of the multi-domain path A-E-F (which
is 100, in the best case) will be always be higher than the cost
of the multi-domain paths A-D-F (which is 90, in the worst case)
and A-E-F (which is 80, in the worst case)
Therefore, the Orchestrator can understand by its own that the
optimal multi-domain path could be either A-D-F or A-E-F but it
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cannot known which one of the two possible option actually provides
the optimal end-to-end path.
The Orchestrator can therefore request path computation only to the
TE domain controllers A, D, E and F (and not to all the possible TE
domain controllers).
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Figure 8 - Multi-domain with many domains (Path Computation
information)
Based on these requests, the Orchestrator can know the actual cost
of each intra-domain paths which belongs to potential optimal end-
to-end paths, as shown in Figure 8, and then compute the optimal
end-to-end path (e.g., A-D-F, having total cost of 50, instead of A-
C-F having a total cost of 70).
4. Motivation for a YANG Model
4.1. Benefits of common data models
Path computation requests should be closely aligned with the YANG
data models that provide (abstract) TE topology information, i.e.,
[TE-TOPO] as well as that are used to configure and manage TE
Tunnels, i.e., [TE-TUNNEL]. Otherwise, an error-prone mapping or
correlation of information would be required. For instance, there is
benefit in using the same endpoint identifiers in path computation
requests and in the topology modeling. Also, the attributes used in
path computation constraints could use the same or similar data
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models. As a result, there are many benefits in aligning path
computation requests with YANG models for TE topology information
and TE Tunnels configuration and management.
4.2. Benefits of a single interface
A typical use case for path computation requests is the interface
between an orchestrator and a domain controller. The system
integration effort is typically lower if a single, consistent
interface is used between such systems, i.e., one data modeling
language (i.e., YANG) and a common protocol (e.g., NETCONF or
RESTCONF).
Practical benefits of using a single, consistent interface include:
1. Simple authentication and authorization: The interface between
different components has to be secured. If different protocols
have different security mechanisms, ensuring a common access
control model may result in overhead. For instance, there may
be a need to deal with different security mechanisms, e.g.,
different credentials or keys. This can result in increased
integration effort.
2. Consistency: Keeping data consistent over multiple different
interfaces or protocols is not trivial. For instance, the
sequence of actions can matter in certain use cases, or
transaction semantics could be desired. While ensuring
consistency within one protocol can already be challenging, it
is typically cumbersome to achieve that across different
protocols.
3. Testing: System integration requires comprehensive testing,
including corner cases. The more different technologies are
involved, the more difficult it is to run comprehensive test
cases and ensure proper integration.
4. Middle-box friendliness: Provider and consumer of path
computation requests may be located in different networks, and
middle-boxes such as firewalls, NATs, or load balancers may be
deployed. In such environments it is simpler to deploy a single
protocol. Also, it may be easier to debug connectivity
problems.
5. Tooling reuse: Implementers may want to implement path
computation requests with tools and libraries that already
exist in controllers and/or orchestrators, e.g., leveraging the
rapidly growing eco-system for YANG tooling.
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4.3. Extensibility
Path computation is only a subset of the typical functionality of a
controller. In many use cases, issuing path computation requests
comes along with the need to access other functionality on the same
system. In addition to obtaining TE topology, for instance also
configuration of services (setup/modification/deletion) may be
required, as well as:
1. Receiving notifications for topology changes as well as
integration with fault management
2. Performance management such as retrieving monitoring and
telemetry data
3. Service assurance, e.g., by triggering OAM functionality
4. Other fulfilment and provisioning actions beyond tunnels and
services, such as changing QoS configurations
YANG is a very extensible and flexible data modeling language that
can be used for all these use cases.
Adding support for path computation requests to YANG models would
seamlessly complement with [TE-TOPO] and [TE-TUNNEL] in the use
cases where YANG-based protocols (e.g., NETCONF or RESTCONF) are
used.
5. Path Optimization Request
This is for further study
6. YANG Model for requesting Path Computation
Work on extending the TE Tunnel YANG model to support the need to
request path computation has recently started also in the context of
the [TE-TUNNEL] draft.
It is possible to request path computation by configuring a
"compute-only" TE tunnel and retrieving the computed path(s) in the
LSP(s) Record-Route Object (RRO) list as described in [TE-TUNNEL].
This is a stateful solution since the state of each created
"compute-only" TE tunnel needs to be maintained and updated, when
underlying network conditions change.
The need also for a stateless solution, based on an RPC, has been
recognized.
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The YANG model to support stateless RPC is for further study.
7. Security Considerations
This is for further study
8. IANA Considerations
This document requires no IANA actions.
9. References
9.1. Normative References
[RFC7926] Farrel, A. et al., "Problem Statement and Architecture for
Information Exchange Between Interconnected Traffic
Engineered Networks", RFC 7926, July 2016.
[TE-TOPO] Liu, X. et al., "YANG Data Model for TE Topologies",
draft-ietf-teas-yang-te-topo, work in progress.
[TE-TUNNEL] Xhang, X. et al., "A YANG Data Model for Traffic
Engineering Tunnels and Interfaces", draft-ietf-teas-yang-
te, work in progress.
9.2. Informative References
[RFC7446] Lee, Y. et al., "Routing and Wavelength Assignment
Information Model for Wavelength Switched Optical
Networks", RFC 7446, February 2015.
[L1-TOPO] Zhang, X. et al., "A YANG Data Model for Layer 1 (ODU)
Network Topology", draft-zhang-ccamp-l1-topo-yang, work in
progress.
[ACTN-Frame] D, Ceccarelli and Y. Lee (editors), "Framework for
Abstraction and Control of Transport Networks," draft-
ceccarelli-actn-framework, work in progress.
[ACTN-Info] Y. Lee and S. Belotti, D. Dhody and D. Ceccarelli,
"Information Model for Abstraction and Control of
Transport Networks", draft-leebelotti-actn-info, work in
progress.
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10. Acknowledgments
The authors would like to thank Igor Bryskin and Xian Zhang for
participating in discussions and providing valuable insights.
This document was prepared using 2-Word-v2.0.template.dot.
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Contributors
Dieter Beller
Nokia
Email: dieter.beller@nokia.com
Authors' Addresses
Italo Busi
Huawei
Email: italo.busi@huawei.com
Sergio Belotti
Nokia
Email: sergio.belotti@nokia.com
Victor Lopez
Telefonica
Email: victor.lopezalvarez@telefonica.com
Oscar Gonzalez de Dios
Telefonica
Email: oscar.gonzalezdedios@telefonica.com
Anurag Sharma
Infinera
Email: AnSharma@infinera.com
Yan Shi
China Unicom
Email: shiyan49@chinaunicom.cn
Ricard Vilalta
CTTC
Email: ricard.vilalta@cttc.es
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Karthik Sethuraman
NEC
Email: karthik.sethuraman@necam.com
Michael Scharf
Nokia
Email: michael.scharf@nokia.com
Daniele Ceccarelli
Ericsson
Email: daniele.ceccarelli@ericsson.com
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