Internet DRAFT - draft-irtf-nfvrg-resource-management-service-chain
draft-irtf-nfvrg-resource-management-service-chain
Internet Research Task Force (IRTF) S. Lee
Internet-Draft ETRI
Intended status: Informational S. Pack
Expires: September 21, 2016 KU
M-K. Shin
ETRI
E. Paik
KT
R. Browne
Intel
March 20, 2016
Resource Management in Service Chaining
draft-irtf-nfvrg-resource-management-service-chain-03
Abstract
This document specifies problem definition and use cases of NFV
resource management in service chaining for path optimization,
traffic optimization, failover, load balancing, etc. It further
describes design considerations and relevant framework for the
resource management capability that dynamically creates and updates
network forwarding paths (NFPs) considering resource constraints of
NFV infrastructure.
Status of This Memo
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Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Resource management in service chain . . . . . . . . . . . . 5
3.1. Resource scheduling among network services . . . . . . . 5
3.2. Performance guarantee within a service chain . . . . . . 5
3.3. Multiple policies and conflicts . . . . . . . . . . . . . 6
3.4. Dynamic adaptation of service chains . . . . . . . . . . 6
4. Use cases . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1. Fail-over . . . . . . . . . . . . . . . . . . . . . . . . 7
4.2. Load balancing . . . . . . . . . . . . . . . . . . . . . 8
4.3. Path optimization . . . . . . . . . . . . . . . . . . . . 8
4.4. Traffic optimization . . . . . . . . . . . . . . . . . . 8
4.5. Energy efficiency . . . . . . . . . . . . . . . . . . . . 9
5. Evaluation Model . . . . . . . . . . . . . . . . . . . . . . 9
5.1. System Model . . . . . . . . . . . . . . . . . . . . . . 9
5.2. Objective functions . . . . . . . . . . . . . . . . . . . 11
5.2.1. Load balancing . . . . . . . . . . . . . . . . . . . 11
5.2.2. Throughput optimization . . . . . . . . . . . . . . . 11
5.2.3. Energy efficiency . . . . . . . . . . . . . . . . . . 12
6. Framework . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7. Applicability to SFC . . . . . . . . . . . . . . . . . . . . 13
7.1. Related works in IETF SFC WG . . . . . . . . . . . . . . 13
7.2. Integration in SFC control-plane architecture . . . . . . 13
8. Security Considerations . . . . . . . . . . . . . . . . . . . 15
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 15
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
11.1. Normative References . . . . . . . . . . . . . . . . . . 15
11.2. Informative References . . . . . . . . . . . . . . . . . 15
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
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1. Introduction
Network Functions Virtualisation (NFV) [ETSI-NFV-WHITE] offers a new
way to design, deploy and manage network services. The network
service can be composed of one or more network functions and NFV
relocates the network functions from dedicated hardware appliances to
generic servers, so they can run in software. Using these
virtualized network functions (VNFs), one or more VNF forwarding
graphs (VNF-FGs; a.k.a. service chains) can be associated to the
network service, each of which describes a network connectivity
topology, by referencing VNFs and Virtual Links that connect them.
One or more network forwarding paths (NFPs) can be built on top of
such a topology, each defining an ordered sequence of VNFs and
Virtual Links to be traversed by traffic flows matching certain
criteria.
The network service is instantiated by allocating NFVI resources for
VNFs and VLs which constitute the VNF-FGs. Thus, the capacity and
performance of the network service depends on the state and
attributes of the network resources used for its VNF and VL
instances. While this brings a similar problem to the VM placement
optimization in a cloud computing environment, it differs as one or
more VNF instances are interconnected for a single network service.
For example, if one of the VNF instances in the VNF-FG gets failed or
overloaded, the whole network service also gets affected. Thus, the
VNF instances need to be carefully placed during NS instantiation
considering their connectivity within NFPs. They also need to be
monitored and dynamically migrated or scaled at run-time to adapt to
changes in the resources.
The resource management problem in VNF-FGs matters not only to the
performance and capacity of network services but also to the
optimized use of NFVI resources. For example, if processing and
bandwidth burden converges on the VNF instances placed in a specific
NFVI-PoP, it may result in scalability problem of the NFV
infrastructure. Thus care is encouraged to be taken in distributing
load across local and external VNF instances at run-time.
This document addresses resource management problem in service
chaining to optimize the NS performance and NFVI resource usage. It
provides the relevant use cases of the resource management such as
traffic optimization, failover, load balancing and further describes
design considerations and relevant framework for the resource
management capability that dynamically creates and updates NFP
instances considering NFVI resource states for VNF instances and VL
instances.
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Note that this document mainly focuses on the resource management
capability based on the ETSI NFV framework [ETSI-NFV-ARCH] but also
studies contribution points to the work for control plane of SFC
architecture [I-D.ietf-sfc-architecture]
[I-D.ietf-sfc-control-plane].
2. Terminology
This document uses the following terms and most of them were
reproduced from [ETSI-NFV-TERM].
o Network Functions (NF): A functional building block within a
network infrastructure, which has well-defined external interfaces
and a well-defined functional behavior.
o Network service: A composition of network functions and defined by
its functional and behavioural specification.
o NFV Framework: The totality of all entities, reference points,
information models and other constructs defined by the
specifications published by the ETSI ISG NFV.
o Virtualised Network Function (VNF): An implementation of an NF
that can be deployed on a Network Function Virtualisation
Infrastructure (NFVI).
o NFV Infrastructure (NFVI): The NFV-Infrastructure is the totality
of all hardware and software components which build up the
environment in which VNFs are deployed.
o NFVI-PoP: A location or point of presence that hosts NFV
infrastructure
o VNF Forwarding Graph (VNF-FG): A NF forwarding graph where at
least one node is a VNF.
o Network Forwarding Path (NFP): The sequence of hardware/software
switching ports and operations in the NFV network infrastructure
as configured by management and orchestration that implements a
logical VNF forwarding graph "link" connecting VNF "node" logical
interfaces.
o Virtual Link: A set of connection points along with the
connectivity relationship between them and any associated target
performance metrics (e.g. bandwidth, latency, QoS). The Virtual
Link can interconnect two or more entities (e.g., VNF components,
VNFs, or PNFs).
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3. Resource management in service chain
This section addresses several issues for considerations in NFV
resource management of service chain.
3.1. Resource scheduling among network services
In the NFV framework, network services are realized with NS
instantiation procedures at which virtualized NFVI resources are
assigned to the VNFs and VLs which constitute VNF-FGs of the network
service. The NFVI resources are placed and located along the VNF-FG
by NFV Orchestrator (NFVO) dynamically according to:
o Resource availability,
o Deployment templates which define resource requirements of NS
instances and VNF instances to support KPIs (e.g., capacity and
performance) of the network service, and
o Resource policies which define how to govern NFVI resources for NS
instances and VNF instances (e.g., affinity/anti-affinity rules,
scaling, and fault management) to support an efficient use of NFVI
resources as well as KPIs of the network service.
In order to satisfy the deployment templates and resource policies,
VNF-FGs of the network services need to be built by considering the
state of NFVI resources for VNF instances (e.g., availability,
throughput, load, disk usage) and VL instances (e.g., bandwidth,
delay, delay variation, packet loss).
However, since the NFVI resources are shared by different network
services and their deployment constraints are very different from
each other, it is required to carefully schedule the NFVI resources
for multiple network services to optimize their KPIs.
3.2. Performance guarantee within a service chain
In NFV, a network service is composed of one or more virtualized
network functions which are connected via virtual links along NFPs
specified for a traffic flow for the network service. Thus, the
performance of a network service is determined by the performance and
capability of a coupling of VNF instances and VL instances. For
example, if one of the VNF instances or VL instances of an NFP gets
failed or overloaded, the whole network service also gets affected.
Thus, the VNF instances need to be carefully placed during NS
instantiation considering their connectivity within NFPs.
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This performance coupling can be handled by considering deployment
rules for affinity/anti-affinity, geography, or topological locations
of VNFs; and QoS of virtual links.
Another important factor for virtual links is the inter-connectivity
between different NFVI-PoPs, which is an enabler of resource sharing
among different NFVI-PoPs. When the VNF instances of a network
service are allocated at different NFVI-PoPs, the NFVI-PoP
interconnect may be a bottleneck point which needs to be monitored to
support KPIs of the service chain.
3.3. Multiple policies and conflicts
The NFVI resources for a network service should be allocated and
managed according to a NS policy given in the network service
descriptor (NSD), which describes how to govern NFVI resources for
VNF instances and VL instances to support KPIs of the network
service. The examples of NS policy are affinity/anti-affinity,
scaling, fault and performance, geography, regulatory rules, NS
topology, etc. Since network services may have different NS policies
for their own deployment and performance, this may cause resource
management difficult within the shared NFVI resources.
For network-wide (or NS-wide) resource management, NFVI policy (or
network policy) can be also provided. It may describe the resource
management policy for optimized use of infrastructure resources
rather than the performance of a single network service. The
examples of NFVI policy are NFVI resource access control, reservation
and/or allocation policies, placement optimization based on affinity
and/or anti-affinity rules, geography and/or regulatory rules,
resource usage, etc.
Multiple administrative domains or subsystems may have different NFVI
policies so that it may bring some conflicts when enforcing them in a
global infrastructure. There could be a similar problem among NS
policies and NFVI policies.
Note that the similar topics are being studied in
[I-D.irtf-nfvrg-nfv-policy-arch]
3.4. Dynamic adaptation of service chains
The performance and capability of NFVI resources may vary in time due
to different uses and management policies of the resources. If some
changes in the resources make the service quality unacceptable, the
VNF instances can be scaled according to the given auto-scaling
policies. But it's only for local quality of the VNF.
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In order to provide optimized KPIs to network services, the NFP
instances need to dynamically adapt to the changes of the resource
state at run-time. The performance of the whole NFP instance should
be measured by monitoring the resource state of VNF instances and VL
instances. Based on the monitoring results, some VNF instances may
be determined and relocated at different virtualized resources with
better performance and capabilities.
4. Use cases
In this section, several (but not exhausted) use cases for resource
management in service chaining are provided: fail-over, load
balancing, path optimization, traffic optimization, and energy
efficiency.
4.1. Fail-over
For service continuity, failure of a VNF instance needs to be
detected and the failed one needs to be replaced with the other one
which is available to use as per redundancy policy. Figure 1
presents an example of the fail-over use case. A network service is
defined as a chain of VNF-A and VNF-B; and the service chain is
instantiated with VNF-A1 and VNF-B1 which are instances of VNF-A and
VNF-B, respectively. In the meantime, failure of VNF-B1 is detected
so that VNF-B2 replaces the failed one for fail-over of the NFP.
+--------+ +--------+
| VNF-B2 | #| VNF-B2 |###
+--------+ +--------+ +--------+ # +--------+
###| VNF-A1 | _|_ ###| VNF-A1 |# _|_
+--------+ (___) +--------+ (___)
___/ # / \ \ ___/ / \
(___)+---#------+ + ===} (___)+----------+ +
# \ ___ / / \ ___ /
# (___) (___)
# | |
# +--------+ +--------+
######| VNF-B1 |### (failure)--> | VNF-B1 |
+--------+ +--------+
### NFP
Figure 1: A fail-over use case
The above is in the case where there is a 1+1 or 1:N redundancy
scheme. In event that VNF instance overloads before NFVO has time to
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scale out, or when resources do not permit a scale-out then we can
route the service chain deterministically to a remote VNF instance.
This adaptation may be revertive or non-revertive dependent on
service provider policy and resource availability.
4.2. Load balancing
A single VNF instance may be a bottleneck point of a service chain
due to its overload. It may affect the performance of the whole
service chain consequently so that an NFP instance needs to be built
to avoid bottleneck points or maintained to distribute workloads of
overloaded VNF instances.
With NFVI-PoP Interconnect, service chains can be balanced between
NFVI-PoPs in a way that best utilises NFV infrastructure and ensures
service integrity. The wide area conditions can be monitored in
real-time to provide KPIs, such as BW, delay, delay variation and
packet loss per QoS class to the service chaining application which
may enable use of external VNF instances when there is an overload or
failure condition in the local NFVI-PoP. In this way the service
chaining application can make a service chain reroute decision (in
the event of failure and/or overload) that is network and platform-
aware. The service chaining application understands the state of
external VNFs and WAN conditions per QoS class between the local
NFVI-PoP and remote NFVI-PoP in real-time.
4.3. Path optimization
Traffic for a network service traverses all of the VNF instances and
the connecting VL instances given by a NFP instance to reach a target
end point. Thus, quality of the network service depends on the
resource constraints (e.g., processing power, bandwidth, topological
locations, latency) of VNF instances, VL instances including NFVI-PoP
interconnects. In order to optimize the path of the network service,
the resource constraints of VNF instances and VLs need to be
considered at constructing NFPs. Since the resource state may vary
in time during the service, NFP instances also need to adapt to the
changes of resource constraints of the VNF instances and VL instances
by monitoring and replacing them at run-time.
4.4. Traffic optimization
A network operator may provide multiple network services with
different VNF-FGs and different flows of traffic traverse between
source and destination end-points along the VNF-FGs. For efficiency
of resource usage, the NFP instances need to be built by default to
localize the traffic flows and to avoid processing and network
bottlenecks. It is only in the case of local failure or overload
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(whereby the NFVO is unable or has not completed a scale-out of on-
site resources) that NFP instances would be constructed between NFVI-
PoPs. In this case, multiple VNF instances of different NFVI-PoPs
need to be considered together at constructing a new NFP instance or
adapting one.
4.5. Energy efficiency
Energy efficiency in the network is getting important to reduce
impact on the environment so that energy consumption of VNF instances
using NFVI resources (e.g., compute, storage, I/O) needs to be
considered at NFP instantiation or adaptation. For example, a NFP
can be instantiated as to make traffic flows aggregated into a
limited number of VNF instances as much as its performance is
preserved in a certain level. Policy may vary between centralized or
distributed NFV applications, and could include policies for even
energy distribution between sites, time-of-day etc.
5. Evaluation Model
To derive specific algorithms for use cases discussed in Section 4,
an evaluation model for a service chain (or a NFP) needs to be
developed, which can address two problems for a given network
topology and input parameters (e.g., VL/VNF capacity, incoming
traffic flows, etc.) : 1) how much traffic flows pass on each VL
instance and 2) how much processing capacity is needed for the
installed VNF instance. This section first describes the system
model and then presents main objectives for the evaluation model.
5.1. System Model
The system model considers the following network topology. The
network topology under consideration is composed of start/end points
and multiple NFVI-PoPs where multiple VNF instances locate. On the
other hand, VL instances inter-connect VNF instances in NFVI-PoPs.
Start and end points are incoming and outgoing points of traffic flow
for a given network service, respectively. Specifically, the amount
of incoming traffic flows for a network service (i.e., a VNF-FG) at
the start point is given as an input parameter in the model.
Under the network topology, the network traffic is processed by one
or more VNF instances and delivered via VL instances. Thus, the VNF
processing capacity can be defined as the maximum amount of traffic
flows that a VNF instance can process according to the resource
allocation policies defined in its deployment template. The VL
capacity can be also defined as the maximum amount of traffic flows
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that can pass on a VL instance according to the resource allocation
policies defined in the deployment template.
In NFV, traffic flows for a VNF-FG should be processed according to
the VNF order described in the given VNF-FG. Accordingly, traffic
flows at the start point should not be processed by any VNF.
Meanwhile, traffic flows at the end point should be processed by all
VNFs specified in the given VNF-FG.
In a given VNF-FG, VNFs should be individually placed on multiple
NFVI-PoPs. Therefore, a decision variable, VNF placement indicator
function (VPIF), is defined as:
o VNF placement indicator function (VPIF): indicator function (i.e.,
0 or 1) to represent the location (i.e., a NFVI-PoP) where the VNF
instance is placed.
Intuitively, the amount of traffic flows that pass a VL instance
should not exceed the VL capacity to avoid any overload at the VL
instance. Likewise, the amount of incoming traffic flows to a VNF
instance should not exceed the VNF processing capacity. (These
constraints will be covered in the following paragraphs) Therefore,
traffic flows for a network service (i.e., a VNF-FG) should be
distributed to multiple NFPs depending on resource and capacity
constraints for VNF and VL instances. Moreover, multiple network
services can be supported by distributing traffic flows for each
network service. Therefore, another decision variable, traffic flow
ratio (TFR), is defined as:
o Traffic flow ratio (TFR): the ratio of the traffic flows
distributed to each NFP. Therefore, the amount of traffic flows
that passes on each NFP is the product of TFR and the amount of
incoming traffic flows for a network service. Note that TFR and
the amount of incoming traffic flows can be computed by measuring
the amount of traffic flows that passes on each VL.
The constraints regarding the amount of network traffic and capacity
of VNF and VL instances can be specified as follows.
o Network traffic conservation constraints: In the VNF-FG system
model, the amount of network traffic should be conserved within a
VNF-FG. That is, 1) the amount of incoming network traffic to a
VNF instance should be equal (more or less in case of packet
manipulation) to the amount of outgoing network traffic from the
VNF instance; and 2) the amount of incoming network traffic to a
VNF instance should not exceed the flow rate of the corresponding
NFP which can be determined by TFR.
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o Network traffic processing order constraints: As defined in the
VNF-FG, the network traffic can be processed by a VNF instance
only after being processed by the preceding VNF instances along
the NFP. Similarly, the incoming network traffic to a NFP should
be firstly processed by the VNF instance which is located at the
ingress point of the NFP; and the outgoing network traffic from a
NFP should be the result of processing by every VNF instance in
the order defined by the NFP.
o Link and processing capacity constraints: The amount of incoming
network traffic to a VL instance should not exceed the given link
capacity of the VL to avoid any congestion at the link. Likewise,
the amount of incoming network traffic to a VNF instance should
not exceed the processing capacity of the VNF.
This system model can be exploited to obtain the optimal solutions of
network resource (i.e., VNF and VL instances) placement for network
resource usage, network service throughput, and so on. This
optimization problem can be solved, for example with linear
programming (LP), by defining different objective functions.
5.2. Objective functions
In the evaluation model, three objectives are considered including,
but not limited to, 1) load balancing, 2) flow throughput
maximization, and 3) energy efficiency.
5.2.1. Load balancing
For load balancing for a network service, the remaining capacity for
VNF instances and VL instances should be balanced to avoid any
bottlenecks. To this end, the minimum remaining processing capacity
for VNF instances and the minimum remaining link capacity for VL
instances should be maximized.
5.2.2. Throughput optimization
On the other hand, the flow throughput considers both throughputs for
VNF processing and for VL instance. Then, the throughput of an NFP
can be calculated as the product of TFR and the sum of capacities,
and the total throughput is the sum of computed throughputs for all
NFPs. By maximizing the total flow throughput, it is possible to
reduce the network service time.
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5.2.3. Energy efficiency
Since each VNF instance consumes an amount of energy for processing
its function and transmitting/receiving traffic flows across VL
instances, the energy consumption for each VNF instance should be
minimized for energy efficiency of network services. Detailed model
is under construction.
6. Framework
To support the aforementioned use cases, it is required to support
resource management capability which provides service chain (or NFP)
construction and adaptation by considering resource state or
constraints of VNF instances and VL instances which connect them.
The resource management operations for service chain construction and
adaptation can be divided into several sub-actions:
o Locate VNF instances
o Evaluate the performance of VNF instances and VL instances
o Relocate (or scale) VNF instances to update a NFP instance
o Monitor state or resource constraints of a VNF instance, VL
instances including NFVI-PoP interconnects
As listed above, VNF instances are relocated according to monitoring
or evaluation results of performance metrics of the VNF instances and
VL instances. Studies about evaluation methodologies and performance
metrics for VNF instances and NFVI resources can be found at
[ETSI-NFV-PER001] [I-D.liu-bmwg-virtual-network-benchmark]
[I-D.ietf-bmwg-virtual-net]. The performance metrics of VNF
instances and VL instances specific to service chain construction and
adaptation can be defined as follows:
o availability (or failure) of a VNF instance and a VL instance
o a topological location of a VNF instance
o CPU and memory utilization rate of a VNF instance
o a throughput of a VNF instance
o energy consumption of a VNF instance
o bandwidth of a VL instance
o packet loss of a VL instance
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o latency of a VL instance
o delay variation of a VL instance
The resource management functionality for dynamic service chain
adaptation takes role of NFV orchestration with support of VNF
manager (VNFM) and Virtualised Infrastructure Manager (VIM) in the
NFV framework [ETSI-NFV-ARCH]. Detailed functional building block
and interfaces are still under study.
7. Applicability to SFC
7.1. Related works in IETF SFC WG
IETF SFC WG provides a new service deployment model that delivers the
traffic along the predefined logical paths of service functions
(SFs), called service function chains (SFCs) with no regard of
network topologies or transport mechanisms. Basic concept of the
service function chaining is similar to VNF-FG where a network
service is composed of SFs and deployed by making traffic flows
traversed instances of the SFs in a pre-defined order.
There are several works in progress in IETF SFC WG for resource
management of service chaining. [I-D.ietf-sfc-architecture] defines
SFC control plane that selects specific SFs for a requested SFC,
either statically or dynamically but details are currently outside
the scope of the document. There are other works
[I-D.ietf-sfc-control-plane] [I-D.lee-sfc-dynamic-instantiation]
[I-D.krishnan-sfc-oam-req-framework] [I-D.ietf-sfc-oam-framework]
which define the control plane functionality for service function
chain construction and adaptation but details are still under study.
While [I-D.dunbar-sfc-fun-instances-restoration] and
[I-D.meng-sfc-chain-redundancy] provide detailed mechanisms of
service chain adaptation, they focus only on resilience or fail-over
of service function chains.
7.2. Integration in SFC control-plane architecture
In SFC WG, [I-D.ietf-sfc-control-plane] describes requirements for
conveying information between Service Function Chaining (SFC) control
elements (including management components) and SFC functional
elements. It also identifies a set of control interfaces to interact
with SFC-aware elements to establish, maintain or recover service
function chains.
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+----------------------------------------------+
| |
| SFC Control & Management Planes |
+-------| |
| | |
C1 +------^-----------^-------------^-------------+
+---------------------|C3---------|-------------|-------------+
| | +----+ | | |
| | | SF | |C2 |C2 |
| | +----+ | | |
| +----V--- --+ | | | |
| | SFC | +----+ +-|--+ +----+ |
| |Classifier |---->|SFF |----->|SFF |------->|SFF | |
| | Node |<----| |<-----| |<-------| | |
| +-----------+ +----+ +----+ +----+ |
| | | | |
| |C2 ------- | |
| | | | +-----------+ C4 |
| V +----+ +----+ | SFC Proxy |--> |
| | SF | |SF | +-----------+ |
| +----+ +----+ |
| |C3 |C3 |
| SFC Data Plane Components V V |
+-------------------------------------------------------------+
Figure 2: SFC control plane overview
The service chain adaptation addressed in this document may be
integrated into the SFC Control & Management Planes and may use the
C2 and C4 interfaces for monitoring or collecting the resource
constraints of VNF instances, NFVI-PoP interconnects and VL
instances.
To prevent constant integration between the application and probing
functions we would propose a 3-tier architecture per NFVI-PoP.
o Top level application control at the SFC Control & Management
Planes
o An abstraction layer between the application layer and the probing
layer. This would decouple NFVI and link monitoring methods from
the application layer
o A probing layer that monitors VNF, physical and virtual link
resources
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Note that SFC does not assume that Service Functions are virtualized.
Thus, the parameters of resource constraints may differ, and it needs
further study for integration.
8. Security Considerations
TBD.
9. IANA Considerations
TBD.
10. Contributors
In addition to the authors, the following individuals contributed to
the content.
Insun Jang
Korea University
zerantoss@korea.ac.kr
11. References
11.1. Normative References
[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>.
11.2. Informative References
[ETSI-NFV-ARCH]
ETSI, "ETSI NFV Architectural Framework v1.1.1", October
2013.
[ETSI-NFV-MANO]
ETSI, "Network Function Virtualization (NFV) Management
and Orchestration V0.6.3", October 2014.
[ETSI-NFV-PER001]
ETSI, "Network Function Virtualization: Performance and
Portability Best Practices v1.1.1", June 2014.
[ETSI-NFV-TERM]
ETSI, "NFV Terminology for Main Concepts in NFV", October
2013.
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[ETSI-NFV-WHITE]
ETSI, "NFV Whitepaper 2", October 2013.
[I-D.dunbar-sfc-fun-instances-restoration]
Dunbar, L. and A. Malis, "Framework for Service Function
Instances Restoration", draft-dunbar-sfc-fun-instances-
restoration-00 (work in progress), April 2014.
[I-D.ietf-bmwg-virtual-net]
Morton, A., "Considerations for Benchmarking Virtual
Network Functions and Their Infrastructure", draft-ietf-
bmwg-virtual-net-01 (work in progress), September 2015.
[I-D.ietf-sfc-architecture]
Halpern, J. and C. Pignataro, "Service Function Chaining
(SFC) Architecture", draft-ietf-sfc-architecture-11 (work
in progress), July 2015.
[I-D.ietf-sfc-control-plane]
Li, H., Wu, Q., Huang, O., Boucadair, M., Jacquenet, C.,
Haeffner, W., Lee, S., Parker, R., Dunbar, L., Malis, A.,
Halpern, J., Reddy, T., and P. Patil, "Service Function
Chaining (SFC) Control Plane Components & Requirements",
draft-ietf-sfc-control-plane-03 (work in progress),
January 2016.
[I-D.ietf-sfc-oam-framework]
Aldrin, S., Krishnan, R., Akiya, N., Pignataro, C., and A.
Ghanwani, "Service Function Chaining Operation,
Administration and Maintenance Framework", draft-ietf-sfc-
oam-framework-01 (work in progress), February 2016.
[I-D.irtf-nfvrg-nfv-policy-arch]
Figueira, N., Krishnan, R., Lopez, D., Wright, S., and D.
Krishnaswamy, "Policy Architecture and Framework for NFV
Infrastructures", draft-irtf-nfvrg-nfv-policy-arch-03
(work in progress), March 2016.
[I-D.krishnan-sfc-oam-req-framework]
Krishnan, R., Ghanwani, A., Gutierrez, P., Lopez, D.,
Halpern, J., Kini, S., and A. Reid, "SFC OAM Requirements
and Framework", draft-krishnan-sfc-oam-req-framework-00
(work in progress), July 2014.
[I-D.lee-sfc-dynamic-instantiation]
Lee, S., Pack, S., Shin, M., and E. Paik, "SFC dynamic
instantiation", draft-lee-sfc-dynamic-instantiation-01
(work in progress), October 2014.
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[I-D.liu-bmwg-virtual-network-benchmark]
Liu, V., Liu, D., Mandeville, B., Hickman, B., and G.
Zhang, "Benchmarking Methodology for Virtualization
Network Performance", draft-liu-bmwg-virtual-network-
benchmark-00 (work in progress), July 2014.
[I-D.meng-sfc-chain-redundancy]
Meng, W. and C. Wang, "Redundancy Mechanism for Service
Function Chains", draft-meng-sfc-chain-redundancy-02 (work
in progress), October 2015.
[Jang-2016]
Jang, I., Choo, S., Kim, M., Pack, S., and M. Shin,
"Optimal Network Resource Utilization in Service Function
Chaining", IEEE Conference on Network Softwarization
(NetSoft) (To be publushed), June 2016.
Acknowledgements
The authors would like to thank Sukjin Choo and Myeongsu Kim for the
review and comments.
Authors' Addresses
Seungik Lee
ETRI
218 Gajeong-ro Yuseung-Gu
Daejeon 305-700
Korea
Phone: +82 42 860 1483
Email: seungiklee@etri.re.kr
Sangheon Pack
Korea University
145 Anam-ro, Seongbuk-gu
Seoul 136-701
Korea
Phone: +82 2 3290 4825
Email: shpack@korea.ac.kr
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Myung-Ki Shin
ETRI
218 Gajeong-ro Yuseung-Gu
Daejeon 305-700
Korea
Phone: +82 42 860 4847
Email: mkshin@etri.re.kr
EunKyoung Paik
KT
17 Woomyeon-dong, Seocho-gu
Seoul 137-792
Korea
Phone: +82 2 526 5233
Email: eun.paik@kt.com
Rory Browne
Intel
Dromore House, East Park
Shannon, Co. Clare
Ireland
Phone: +353 61 477400
Email: rory.browne@intel.com
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