Teas Working Group Young Lee
Internet Draft Huawei
Intended status: Informational Sergio Belotti
Alcatel-Lucent
Expires: January 2017
Dhruv Dhody
Huawei
Daniele Ceccarelli
Ericsson
Bin Young Yun
ETRI
July 20, 2016
Information Model for Abstraction and Control of TE Networks (ACTN)
draft-leebelotti-teas-actn-info-04.txt
Abstract
This draft provides an information model for abstraction and control
of Traffic Engineered (TE) networks (ACTN).
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This Internet-Draft will expire on January 20, 2017.
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Table of Contents
1. Introduction...................................................3
2. ACTN Common Interfaces Information Model.......................4
2.1. VN Action Primitives......................................6
2.1.1. VN Instantiate.......................................7
2.1.2. VN Modify............................................7
2.1.3. VN Delete............................................7
2.1.4. VN Update............................................7
2.1.5. VN Path Compute......................................8
2.1.6. VN Query.............................................8
2.1.7. TE Update (for TE resources).........................9
2.2. VN Objects................................................9
2.2.1. VN Identifier.......................................10
2.2.2. VN Characteristics..................................10
2.2.3. VN End-Point (aka Access Point).....................13
2.2.4. VN Action Status....................................13
2.2.5. VN Associated LSP...................................14
2.2.6. VN Preference.......................................14
2.3. Mapping of VN Primitives with VN Objects.................14
3. References....................................................16
3.1. Normative References.....................................16
3.2. Informative References...................................16
4. Contributors..................................................17
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Contributors' Addresses..........................................17
Authors' Addresses...............................................17
Appendix A: ACTN Applications....................................18
A.1. Coordination of Multi-destination Connectivity
Requirement/Policy.........................................18
A.2. Application Policy-aware Network Operation............20
A.3. Network Function Virtualization Service Enabled
Connectivity...............................................22
A.4. Dynamic Service Control Policy Enforcement for
Performance and Fault Management...........................24
A.5. E2E VN Survivability and Multi-Layer (Packet-Optical)
Coordination for Protection/Restoration....................25
1. Introduction
This draft provides an information model for the requirements
identified in the ACTN requirements [ACTN-Req] and the ACTN
interfaces identified in the ACTN architecture and framework
document [ACTN-Frame].
The purpose of this draft is to put all information elements of ACTN
in one place before proceeding to development work necessary for
protocol extensions and data models.
The ACTN reference architecture identified a three-tier control
hierarchy as depicted in Figure 1:
- Customer Network Controllers (CNC)
- Multi-Domain Service Coordinator (MDSC)
- Physical Network Controllers (PNC).
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+-------+ +-------+ +-------+
| CNC-A | | CNC-B | | CNC-C |
+-------+ +-------+ +-------+
\___________ | ____________ _/
---------- | CMI ------------
\ | /
+-----------------------+
| MDSC |
+-----------------------+
_________/ | \_________
-------- | MPI ------------____
/ | \
+-------+ +-------+ +-------+
| PNC | | PNC | | PNC |
+-------+ +-------+ +-------+
Figure 1: A Three-tier ACTN control hierarchy
The two interfaces with respect to the MDSC, one north of the MDSC
and the other south of the MDSC are referred to as CMI (CNC-MDSC
Interface) and MPI (MDSC-PNC Interface), respectively. It is
intended to model these two interfaces and derivative interfaces
thereof (e.g., MDSC to MSDC in a hierarchy of MDSCs) with one common
model.
Appendix A provides some relevant ACTN use-cases extracted from
[ACTN-Req]. Appendix A is information only and may help readers
understand the context of key use-cases addressed in [ACTN-Req].
2. ACTN Common Interfaces Information Model
This section provides ACTN common interface information model to
describe in terms of primitives, objects, their properties
(represented as attributes), their relationships, and the resources
for the service applications needed in the ACTN context.
Basic primitives (messages) are required between the CNC-MDSC and
MDSC-PNC controllers. These primitives can then be used to support
different ACTN network control functions like network topology
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request/query, VN request, path computation and connection control,
VN policy negotiation, enforcement, routing options, etc.
The standard interface is described between a client controller and
a server controller. A client-server relationship is recursive
between a CNC and a MDSC and between a MDSC and a PNC. In the CMI,
the client is a CNC while the server is a MDSC. In the MPI, the
client is a MDSC and the server is a PNC. There may also be MDSC-
MDSC interface(s) that need to be supported. This may arise in a
hierarchy of MDSCs in which workloads may need to be partitioned to
multiple MDSCs.
1. A Virtual Network (VN) may comprise a set of end-to-end tunnels from a
customer point of view that connects customer endpoints (i.e., source
CE and destination CE).
2. A VN may comprise of a number of virtual nodes and virtual links (more
than a tunnel).
For both cases, the CNC can dynamically add VN elements. For case 1,
the VN element is an end-to-end tunnel and for case 2, the VN
element can be virtual nodes and virtual links (more detailed view).
A Virtual Network Service (VNS) is the creation and offering of a
Virtual Network by a provider to a customer in accordance with SLA
agreements reached between them (e.g., re satisfying the customer's
objectives). Such agreements may be negotiated statically or
dynamically; in the latter case VNs may be dynamically created,
deleted, or modified in response to requests from the
customer. This implies dynamic changes of network resources
reserved for the customer. The customer may then act upon the
virtual network resources to perform connection management (set-
up/release/modify connections)
Abstract topology: Every lower controller in the provider network,
when is representing its network topology to an higher layer, it may
want to hide details of the actual network topology. In such case,
an abstract topology may be used for this purpose. Abstract topology
enhances scalability for the MDSC to operate multi-domain
networks.
Basic primitives (messages) are required between the CNC-MDSC and
MDSC-PNC controllers. These primitives can then be used to support
different ACTN network control functions like network topology
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request/query, VN request, path computation and connection control,
VN policy negotiation, enforcement, routing options, etc.
At a minimum, the following VN action primitives should be
supported:
- VN Instantiate (See Section 2.1.1. for the description)
- VN Modify (See Section 2.1.2. for the description)
- VN Delete (See Section 2.1.3. for the description)
- VN Update ((See Section 2.1.4. for the description)
- VN Path Compute (See Section 2.1.5. for the description)
- VN Query (See Section 2.1.6. for the description)
In addition to VN action primitives, TE Update primitive should also
be supported (See Section 2.1.7. for the description).
2.1. VN Action Primitives
This section provides a list of main primitives necessary to satisfy
ACTN requirements specified in [ACTN-REQ].
<VN Action> describes main primitives. VN Action can be one of the
following primitives: (i) Instantiate; (ii) Modify; (iii) Delete;
(iv) Update; (v) Path Compute; (vi) Query.
<VN Action> ::= <VN Instantiate> |
<VN Modify> |
<VN Delete> |
<VN Update> |
<VN Path Compute> |
<VN Query>
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2.1.1. VN Instantiate
<VN Instantiate> refers to an action from customers/applications to
request their VNs. This primitive can also be applied from an MDSC
to a PNC requesting a VN (if the domain the PNC supports can
instantiate the entire VN) or a part of VN elements.
1. A VN may comprise a set of end-to-end tunnels from a customer point
of view that connects customer endpoints (i.e., source CE and
destination CE).
2. A VN may comprise of a number of virtual nodes and virtual links
(more than a tunnel).
For both cases, the CNC can dynamically add VN elements. For case 1,
the VN element is an end-to-end tunnel and for case 2, the VN
element can be virtual nodes and virtual links (more detailed view).
2.1.2. VN Modify
<VN Modify> refers to an action from customers/applications to
modify an existing VN (i.e., instantiated VN). This primitive can
also be applied from an MDSC to a PNC requesting a VN (if the domain
the PNC supports can instantiate the entire VN) or a part of VN
elements.
2.1.3. VN Delete
<VN Delete> refers to an action from customers/applications to
delete an existing VN. This primitive can also be applied from an
MDSC to a PNC requesting a VN (if the domain the PNC supports can
instantiate the entire VN) or a part of VN elements.
2.1.4. VN Update
<VN Update> refers to any update to the VN that need to be updated
to the subscribers. VN Update fulfills a push model.
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Note the VN Update means the connection-related information (e.g.,
LSPs) update that has association with VNs. See Section 2.2.6 for
further details.
There are other existing and upcoming TE mechanisms to fulfill the
same function as VN Update. VN Update can be built on these other
existing TE mechanisms. The details are TDB.
2.1.5. VN Path Compute
<VN Path Compute> consists of Request and Reply. Request refers to
an action from customers/applications to request a VN path
computation. This primitive can also be applied from an MDSC to a
PNC requesting a VN (if the domain the PNC supports can instantiate
the entire VN) or a part of VN elements.
<VN Path Compute> Reply refers to the reply in response to <VN Path
Compute> Request.
<VN Path Compute> Request/Reply is to be differentiated from a VN
Instantiate. The purpose of VN Path Compute is a priori exploration
to estimate network resources availability and getting a list of
possible paths matching customer/applications constraints. To make
this type of request Customer/application controller can have a
shared (with lower controller) view of an abstract network topology
on which to get the constraints used as input in Path Computation
request. The list of paths obtained by the request can be used by
customer/applications to give path constrains during VNS
connectivity request and to compel the lower level controller (e.g.
MDSC) to select the path that Client/application controller has
chosen among the set of paths returned by the Path Computation
primitives. The importance of this primitives is for example in a
scenario like multi-domain in which the optimal path obtained by an
orchestrator as sum of optimal paths for different domain controller
cannot be the optimal path in the Client/application controller
prospective. This only applies between CNC and MDSC.
2.1.6. VN Query
<VN Query> refers to any query pertaining to the VN that has been
already instantiated. VN Query fulfills a pull model and permit to
get topology view.
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<VN Query Reply> refers to the reply in response to <VN Query>.
2.1.7. TE Update (for TE resources)
<TE Update> it is a primitives specifically related to MPI
interface to provide TE resource update between any domain
controller towards MDSC regarding the entire content of any "domain
controller" TE topology or an abstracted filtered view of TE
topology depending on negotiated policy.
<TE Update> ::= [<Abstraction>]<TE-topology>
<TE-topology> ::= <TE-Topology-reference> <Node-list> <Link-list>
<Node-list> ::= <Node>[<Node-list>]
<Node> ::= <Node> <TE-Termination Points>
<Link-list> ::= <Link>[<Link-list>]
Where
<Abstraction> provides information on level of abstraction (as
determined a priori).
<TE-topology-reference> ::= information related to the specific te-
topology related to nodes and links present in this TE-topology.
<Node-list> ::= detailed information related to a specific node
belonging to a te-topology e.g. te-node-attributes.
<Link-list> ::= information related to the specific link related
belonging to a te-topology e.g. te-link-attributes.
<TE-Termination Points> ::= information details associated to the
termination point of te-link related to a specific node.
2.2. VN Objects
This section provides a list of objects associated to VN action
primitives.
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2.2.1. VN Identifier
<VN Identifier> is a unique identifier of the VN.
2.2.2. VN Characteristics
VN Characteristics describes the customer/application requirements
against the VNs to be instantiated.
<VN Characteristics> ::= <VN Connectivity Type>
(<VN Connectivity Matrix>...)
<VN Survivability>
Where
<VN Connectivity Type> ::= <P2P>|<P2MP>|<MP2MP>|<MP2P>|<Multi-
destination>
The Connectivity Type identifies the type of required VN. In
addition to the classical type of connectivity (e.g. P2P/P2MP etc.),
ACTN defines the "multi-destination" connectivitywhere for a given
source, the end points are not fixed. They can be chosen among a
list of pre-configured end points or dynamically provided by the
CNC.
<VN Connectivity Matrix> ::= <Bandwidth>
[<VN Constraints>]
The VN Connectivity Matrix represents the traffic matrix parameters
required against the VN request instantiation between each pair of
Access Points. Bandwidth is a mandatory parameter and a number of
optional constrains can be specified in the <VN Constrains> (e.g.
diversity, cost). They can include objective functions and TE
metrics bounds as specified in [RFC5441].
Further details on the VN constraints are specified below:
<VN Constraints> ::= [<Data Transport>]
[<Diversity>]
[<Shared Risk>]
[<Metric>]
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Where:
<Data Transport>: Identifies the data transport layer at which
the VN is requested. It could be for example MPLS, ODU, OCh.
<Diversity>: This allows asking for diversity constraints for a
path computation or VN instantiation. E.g. a new VN in total
diversity from an existing one or a end-to-end tunnels (VN
members) in a VN are in total diversity among them.
<Shared Risk>: Based on the realization of VN required, group of
physical resources can be impacted by the same risk. End-to-end
tunnels can be impacted by this shared risk.. This is used to get
the SRLG associated to the different tunnels (i.e., VN members)
composing a VN. <Metric> includes all the Metrics, Objective
Functions and Bandwidth Utilization parameters defined and
referenced by [DRAFT-SER-AWARE].
<VN Survivability> describes all attributes related to the VN
recovery level and its survivability policy enforced by the
customers/applications.
<VN Survivability> ::= <VN Recovery Level>
[<VN Tunnel Recovery Level>]
[<VN Survivability Policy>]
Where:
<VN Recovery Level> It is a value representing the requested
level of resiliency required against the VN. The following
values are defined:
. Unprotected VN
. VN with per tunnel recovery: The recovery level is defined
against the tunnels composing the VN and it is specified in
the <VN Tunnel Recovery Level>. It applies to a given data
transport layer).
. Multi-layer coordinated VN recovery. The multi layer VN is
composed by multiple VN at different data transport layer.
A coordination mechanism is provided and specified in
<Multi-Layer Coordination> (inside the VN Survivability
Policy). An example of multi-layer coordinated VN could be
an IPoWDM scenario in which a VN at the WDM layer is
request with given per tunnel recovery (e.g. On the fly
restoration) and at the same time a VN in the IP layer is
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instantiated with its own per tunnel recovery (e.g. 1+1).
This values indicates the need to have the controller
perform a coordination between the two VNs in order to
avoid all the issues of uncoordinated recovery mechanism at
different layers.
<VN Tunnel Recovery Level> ::= <0:1>|<1+1>|<1:1>|<1:N>|<M:N>
<On the fly restoration>
VN Recovery Level indicates the type of protection or
restoration mechanism applied to the VN. It augments the
recovery types defined in [RFC4427].
<VN Survivability Policy> ::= [<Local Reroute Allowed>]
[<Domain Preference>]
[<Push Allowed>]
[<Incremental Update>]
[<Multi-layer VN Coordination>]
Where:
<Local Reroute Allowed> is a delegation policy to the Server
to allow or not a local reroute fix upon a failure of the
primary LSP.
<Domain Preference> is only applied on the MPI where the MDSC
(client) provides a domain preference to each PNC
(server).e.g. when a inter-domain link fails, then PNC can
choose the alternative peering with this info.
<Push Allowed> is a policy that allows a server to trigger an
updated VN topology upon failure without an explicit request
from the client. Push action can be set as default unless
otherwise specified.
<Incremental Update> is another policy that triggers an
incremental update from the server since the last period of
update. Incremental update can be set as default unless
otherwise specified.
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<Multi-layer VN coordination> provides a coordination
mechanism (either by the MDSC or the CNC) between PNCs
implementing VN at different data transport layer.
2.2.3. VN End-Point (aka Access Point)
<VN End-Point> Object describes the VN's customer end-point
characteristics.
<VN End-Point> ::= (<Access Point identifier>
[<Client Interface Capability>]
[<Source Indicator>])...
Where:
<Access point identifier>: It represents a unique identifier of
the client end-point. They are used by the customer to ask for the
setup of a virtual network creation. A <VN End-Point> is defined
against each AP in the network and is shared between customer and
provider. Both the customer and the provider will map it against
his own physical resources.
<Client Interface Capability>: An optional object that identifies
the capabilities of the access link related to the given access
point. (e.g.max-bandwidth, bandwidth availability, etc..)
<Source Indicator> indicates if an End-point is source or not.
2.2.4. VN Action Status
<VN Action Status> is the status indicator whether the VN has been
successfully instantiated, modified, or deleted in the server
network or not in response to a particular VN action.
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2.2.5. VN Associated LSP
<VN Associated LSP> describes the instantiated LSPs that is
associated with the VN. <VN Associated LSP> is used between each
domain PNC and the MDSC as part of VN Update once the VN is
instantiated in each domain network.
<VN Associated LSP> ::= <VN Identifier> (<LSP>...)
2.2.6. VN Preference
This section provides VN preference. VN is defined in Section 2.
<VN Preference> ::= [<Location Servic Preference >]
[<Client-specific Preference >]
[<End-Point Dynamic Selection Preference >]
Where
<Location Service Preference> describes the End-Point Location's
support for certain Virtual Network Functions (VNFs) (e.g.,
security function, firewall capability, etc.).
<Client-specific Preference> describes any preference related to
Virtual Network where application/client can enforce via CNC
towards lower level controllers. For example, permission the
correct selection from the network of the destination related to
the indicated VNF It is e.g. the case of VM migration among data
center and CNC can enforce specific policy that can permit
MDSC/PNC to calculate the correct path for the connectivity
supporting the data center interconnection required by
application.
<End-Point Dynamic Selection Preference> describes if the End-
Point can support load balancing, disaster recovery or VM
migration and so can be part of the selection by MDSC following
Preference enforcement by CNC.
2.3. Mapping of VN Primitives with VN Objects
This section describes the mapping of VN Primitives with VN Objects
based on Section 2.2.
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<VN Instantiate> ::= <VN Characteristics>
<VN End-Point>
[<VN Survivability>]
[<VN Preference>]
<VN Modify> ::= <VN identifier>
<VN Characteristics >
<VN End-Point>
[<VN Survivability>]
[<VN Preference>]
<VN Delete> ::= <VN Identifier>
<VN Update> :: = <VN Identifier>
<VN Associated LSP>
<VN Path Compute Request> ::= <VN Identifier>
<VN Characteristics >
<VN End-Point>
[<VN Survivability>]
[<VN Preference>]
<VN Path Compute Reply> ::= <VN Identifier>
<VN Associated LSP>
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<VN Query> ::= <VN Identifier>
<VN Query Reply> ::= <VN Identifier>
<VN Associated LSP>
3. References
3.1. Normative References
[DRAFT-SER-AWARE] Dhruv Dhody, Qin Wu, Vishwas Manral, Zafar Ali,
and Kenji Kumaki, "Extensions to the Path Computation
Element Communication Protocol (PCEP) to compute service
aware Label Switched Path (LSP).," June 2016, draft-ietf-
pce-pcep-service-aware-10.
3.2. Informative References
[ACTN-Req] Y. Lee, et al., "Requirements for Abstraction and Control
of Transport Networks", draft-lee-teas-actn-requirements,
work in progress.
[ACTN-Frame] D. Ceccarelli, et al., "Framework for Abstraction and
Control of Transport Networks", draft-ietf-teas-actn-
framework, work in progress.
[Stateful-PCE] E. Crabbe, et al., "PCEP Extensions for Stateful
PCE", draft-ietf-pce-stateful-pce, work in progress.
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4. Contributors
Contributors' Addresses
Authors' Addresses
Young Lee (Editor)
Huawei Technologies
5340 Legacy Drive
Plano, TX 75023, USA
Phone: (469)277-5838
Email: leeyoung@huawei.com
Sergio Belotti (Editor)
Alcatel Lucent
Via Trento, 30
Vimercate, Italy
Email: sergio.belotti@alcatel-lucent.com
Dhruv Dhoddy
Huawei Technologies,
Divyashree Technopark, Whitefield
Bangalore, India
Email: dhruv.ietf@gmail.com
Daniele Ceccarelli
Ericsson
Torshamnsgatan,48
Stockholm, Sweden
Email: daniele.ceccarelli@ericsson.com
Bin Young Yun
ETRI
Email: byyun@etri.re.kr
Haomian Zheng
Huawei Technologies
Email: zhenghaomian@huawei.com
Xian Zhang
Huawei Technologies
Email: zhang.xian@huawei.com
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Appendix A: ACTN Applications
A.1. Coordination of Multi-destination Connectivity Requirement/Policy
+----------------+
| CNC |
| (Global DC |
| Operation |
| Control) |
+--------+-------+
| | VN Requirement/Policy:
| | - Endpoint/DC location info
| | - Endpoint/DC dynamic
| | selection policy
| | (for VM migration, DR, LB)
| v
+---------+---------+
| Multi-domain | Service policy-driven
|Service Coordinator| dynamic DC selection
+-----+---+---+-----+
| | |
| | |
+----------------+ | +----------------+
| | |
+-----+-----+ +-----+------+ +------+-----+
| PNC for | | PNC for | | PNC for |
| Transport | | Transport | | Transport |
| Network A | | Network B | | network C |
+-----------+ +------------+ +------------+
| | |
+---+ ------ ------ ------ +---+
|DC1|--//// \\\\ //// \\\\ //// \\\\---+DC5|
+---+ | | | | | | +---+
| TN A +-----+ TN B +----+ TN C |
/ | | | | |
/ \\\\ //// / \\\\ //// \\\\ ////
+---+ ------ / ------ \ ------ \
|DC2| / \ \+---+
+---+ / \ |DC6|
+---+ \ +---+ +---+
|DC3| \|DC4|
+---+ +---+
DR: Disaster Recovery
LB: Load Balancing
Figure A.1: Service Policy-driven Data Center Selection
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Figure A.1 shows how VN policies from the CNC are incorporated by
the MDSC to support multi-destination applications. Multi-
destination applications refer to applications in which the
selection of the destination of a network path for a given source
needs to be decided dynamically to support such applications.
Data Center selection problems arise for VM mobility, disaster
recovery and load balancing cases. VN's policy plays an important
role for virtual network operation. Policy can be static or dynamic.
Dynamic policy for data center selection may be placed as a result
of utilization of data center resources supporting VNs. The MDSC
would then incorporate this information to meet the objective of
this application.
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A.2. Application Policy-aware Network Operation
+----------------+
| CNC |
| (Global DC |
| Operation |
| Control) |
+--------+-------+
| | Application Policy
| | - VNF requirement (e.g.
| | security function, etc.)
| | - Location profile for each VNF
| v
+---------+---------+
| Multi-domain | Dynamically select the
|Service Coordinator| network destination to
+-----+---+---+-----+ meet VNF requirement.
| | |
| | |
+---------------+ | +----------------+
| | |
+------+-----+ +-----+------+ +------+-----+
| PNC for | | PNC for | | PNC for |
| Transport | | Transport | | Transport |
| Network A | | Network B | | network C |
| | | | | |
+------------+ +------------+ +------------+
| | |
{VNF b} | | | {VNF b,c}
+---+ ------ ------ ------ +---+
|DC1|--//// \\\\ //// \\\\ //// \\\\-|DC5|
+---+ | | | | | |+---+
| TN A +---+ TN B +--+ TN C |
/ | | | | |
/ \\\\ //// / \\\\ //// \\\\ ////
+---+ ------ / ------ \ ------ \
|DC2| / \ \\+---+
+---+ / \ |DC6|
{VNF a} +---+ +---+ +---+
|DC3| |DC4| {VNF a,b,c}
+---+ +---+
{VNF a, b} {VNF a, c}
Figure A.2: Application Policy-aware Network Operation
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This scenario is similar to the previous case in that the VN policy
for the application can be met by a set of multiple destinations
that provide the required virtual network functions (VNF). Virtual
network functions can be, for example, security functions required
by the VN application. The VN policy by the CNC would indicate the
locations of a certain VNF that can be fulfilled. This policy
information is critical in finding the optimal network path subject
to this constraint. As VNFs can be dynamically moved across
different DCs, this policy should be dynamically enforced from the
CNC to the MDSC and the PNCs.
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A.3. Network Function Virtualization Service Enabled Connectivity
+----------------+
| CNC |
| (Global DC |
| Operation |
| Control) |
+--------+-------+
| | Policy related to VNF
| | (e.g., firewall, traffic
| | optimizer)
| |
| v
+---------+---------+
| Multi-domain | Select network
|Service Coordinator| connectivity subject to
+-----+---+---+-----+ meeting policy
| | |
| | |
+---------------+ | +----------------+
| | |
+------+-----+ +-----+------+ +------+-----+
| PNC for | | PNC for | | PNC for |
| Transport | | Transport | | Transport |
| Network A | | Network B | | network C |
| | | | | |
+------------+ +------------+ +------------+
| | |
| | |
+---+ ------ ------ ------ +---+
|DC1|--//// \\\\ //// \\\\ //// \\\\-|DC5|
+---+ | | | | | |+---+
| TN A +---+ TN B +--+ TN C |
/ | | | | |
/ \\\\ //// / \\\\ //// \\\\ ////
+---+ ------ / ------ \ ------ \
|DC2| / \ \\+---+
+---+ / \ |DC6|
+---+ +---+ +---+
|DC3| |DC4|
+---+ +---+
Figure A.3: Network Function Virtualization Enabled Connectivity
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Network Function Virtualization Services are usually setup between
customers' premises and service provider premises and are provided
mostly by cloud providers or content delivery providers. The context
may include, but not limited to a security function like firewall, a
traffic optimizer, the provisioning of storage or computation
capacity where the customer does not care whether the service is
implemented in a given data center or another. The customer has to
provide (and CNC is providing this)the type of VNF he needs and the
policy associated with it (e.g. metric like estimated delay to reach
where VNF is located in the DC). The policy linked to VNF is
requested as part of the VN instantiation. These services may be
hosted virtually by the provider or physically part of the network.
This allows the service provider to hide his own resources (both
network and data centers) and divert customer requests where most
suitable. This is also known as "end points mobility" case and
introduces new concepts of traffic and service provisioning and
resiliency (e.g., Virtual Machine mobility).
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A.4. Dynamic Service Control Policy Enforcement for Performance and
Fault Management
+------------------------------------------------+
| Customer Network Controller |
+------------------------------------------------+
1.Traffic| /|\4.Traffic | /|\
Monitor& | | Monitor | | 8.Traffic
Optimize | | Result 5.Service | | modify &
Policy | | modify& | | optimize
\|/ | optimize Req.\|/ | result
+------------------------------------------------+
| Multi-domain Service Coordinator |
+------------------------------------------------+
2. Path | /|\3.Traffic | /|\
Monitor | | Monitor | |7.Path
Request | | Result 6.Path | | modify &
| | modify& | | optimize
\|/ | optimize Req.\|/ | result
+------------------------------------------------+
| Physical Network Controller |
+------------------------------------------------+
Figure A.4: Dynamic Service Control for Performance and Fault
Management
Figure A.4 shows the flow of dynamic service control policy
enforcement for performance and fault management initiated by
customer per VN. The feedback loop and filtering mechanism tailored
for VNs performed by the MDSC differentiates this ACTN scope from
traditional network management paradigm. VN level dynamic OAM data
model is a building block to support this capability.
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A.5. E2E VN Survivability and Multi-Layer (Packet-Optical) Coordination
for Protection/Restoration
+----------------+
| Customer |
| Network |
| Controller |
+--------*-------+
* | E2E VN Survivability Req.
* | - VN Protection/Restoration
* v - 1+1, Restoration, etc.
+------*-----+ - End Point (EP) info.
| |
| MDSC | MDSC enforces VN survivability
| | requirement, determining the
| | optimal combination of Packet/
+------*-----+ Optical protection/restoration
* Optical bypass, etc.
*
*
**********************************************
* * * *
+----*-----+ +----*----+ +----*-----+ +----*----+
|PNC for | |PNC for | |PNC for | |PNC for |
|Access N. | |Packet C.| |Optical C.| |Access N.|
+----*-----+ +----*----+ +----*-----+ +---*-----+
* --*--- * *
* /// \\\ * *
--*--- | Packet | * ----*-
/// \\\ | Core +------+------/// \\\
| Access +----\\ /// * | Access |
| Network | ---+-- * | Network | +---+
|\\\ /// | * \\\ ///---+EP6|
| +---+- | | -----* -+---+ +---+
+-+-+ | | +----/// \\\ | |
|EP1| | +--------------+ Optical | | | +---+
+---+ | | Core +------+ +--+EP5|
+-+-+ \\\ /// +---+
|EP2| ------ |
+---+ | |
+--++ ++--+
|EP3| |EP4|
+---+ +---+
Figure A.5: E2E VN Survivability and Multi-layer Coordination for
Protection and Restoration
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Figure A.5 shows the need for E2E protection/restoration control
coordination that involves CNC, MDSC and PNCs to meet the VN
survivability requirement. VN survivability requirement and its
policy need to be translated into multi-domain and multi-layer
network protection and restoration scenarios across different
controller types. After an E2E path is setup successfully, the MDSC
has a unique role to enforce policy-based flexible VN survivability
requirement by coordinating all PNC domains.
As seen in Figure A.5, multi-layer (i.e., packet/optical)
coordination is a subset of this E2E protection/restoration control
operation. The MDSC has a role to play in determining an optimal
protection/restoration level based on the customer's VN
survivability requirement. For instance, the MDSC needs to interface
the PNC for packet core as well as the PNC for optical core and
enforce protection/restoration policy as part of the E2E
protection/restoration. Neither the PNC for packet core nor the PNC
for optical core is in a position to be aware of the E2E path and
its protection/restoration situation. This role of the MDSC is
unique for this reason. In some cases, the MDSC will have to
determine and enforce optical bypass to find a feasible reroute path
upon packet core network failure which cannot be resolved the packet
core network itself.
To coordinate this operation, the PNCs will need to update its
domain level abstract topology upon resource changes due to a
network failure or other factors. The MDSC will incorporate all
these update to determine if an alternative E2E reroute path is
necessary or not based on the changes reported from the PNCs. It
will need to update the E2E abstract topology and the affected CN's
VN topology in real-time. This refers to dynamic synchronization of
topology from Physical topology to abstract topology to VN topology.
MDSC will also need to perform the path restoration signaling to the
affected PNCs whenever necessary.
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