Thesis no: MSEE-2016-43 Faculty of Computing Blekinge Institute of Technology SE-371 79 Karlskrona Sweden APPLYING LEAN PRINCIPLES FOR PERFORMANCE ORIENTED SERVICE DESIGN OF VIRTUAL NETWORK FUNCTIONS FOR NFV INFRASTRUCTURE SASANK SAI SUJAN ADAPA Concepts of Lean
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Thesis no: MSEE-2016-43
Faculty of Computing
Blekinge Institute of Technology
SE-371 79 Karlskrona Sweden
APPLYING LEAN PRINCIPLES FOR
PERFORMANCE ORIENTED SERVICE
DESIGN OF VIRTUAL NETWORK
FUNCTIONS FOR NFV
INFRASTRUCTURE
SASANK SAI SUJAN ADAPA
Concepts of Lean
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This thesis is submitted to the Faculty of Computing at Blekinge Institute of Technology in partial
fulfillment of the requirements for the degree of Masters in Electrical Engineering with emphasis
on Telecommunication Systems. The thesis is equivalent to 60 weeks of full time studies.
Department of Communication Systems School of Computing
BTH, Karlskrona
Faculty of Computing
Blekinge Institute of Technology
SE-371 79 Karlskrona, Sweden
Internet : www.bth.se
Phone : +46 455 38 50 00
Fax : +46 455 38 50 57
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ABSTRACT
Context. Network Function Virtualization was recently proposed by European Telecommunications
Standards Institute (ETSI) to improve the network service flexibility by virtualization of network
services and applications that run on hardware. To virtualize network functions, the software is
decoupled from underlying physical hardware. NFV aims to transform industries by reducing capital
investments on hardware by using commercial-of-the-shelf (COTS) hardware. NFV makes rapid
innovative growth in telecom services through software based service deployment.
Objectives. This thesis work aims to investigate how business organizations function and the roles in
defining a service relationship model. The work also aims to define a service relationship model and to
validate it via proof of concept using network function virtualization as a service. For this thesis, we
finally apply lean principles for the defined service relationship model to reduce waste and investigate
how lean benefits the model to be proven as performance service oriented.
Methods. The essence of this work is to make a business organization lean by investigating its actions
and applying lean principles. To elaborate, this thesis work involves in a research of papers from IEEE,
TMF, IETF and Ericsson. It results in modelling of a PoC by following requirement analysis
methodology and by applying lean principles to eliminate unnecessary processes which doesn’t add any
value.
Results. The results of the work include a full-fledged service relationship model that include three
service levels with roles that can fit in to requirement specifications of NFV infrastructure. The results
also show the service levels functionalities and their relationships between the roles. It has also been
observed that the services that are needed to be standardized are defined with syntax for ways to describe
network functions. It is observed that lean principles benefit the service relationship model from
reducing waste factors and hereby providing a PoC which is performance service oriented.
Conclusions. We conclude that roles defined are fit for the service relationship model designed.
Moreover, we conclude that the model can hence contain the flow of service by standardizing the sub-
services and reducing waste interpreted with lean principles and there is a need for further use case
proof of the model in full scale industry trials. It also concludes the ways to describe network functions
syntax which follows lean principles that are essential to have them for the sub-services standardization.
However, PoC defined can be an assurance to the NFV infrastructure.
Keywords: Lean Manufacturing, Service, Roles,
Virtualization.
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ACKNOWLEDGEMENTS
I would like to express my heartfelt gratitude to my supervisor Prof. Kurt Tustschku for his
valuable suggestions and endless support throughout the thesis work. His guidance and
comments helped me in exploring the key concepts and techniques in this work.
I would like to express my deep sense of gratitude to my external supervisor Lars Angelin,
BSS Expert at Ericsson for his motivation, suggestions and support throughout my research. I
have learnt a lot from various meetings and crucial discussions with him which enabled me to
improve my way of research for this work.
Also, I am pleased to acknowledge my deep in debt to Jörg Niemöller, Javier G. Viseido and
Malgorzata Svensson for helping me in doing the thesis with Ericsson and introducing Lars
Angelin.
I would also like to thank all my family and friends for their encouragement and full support
towards me.
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ABBREVATIONS
NFV Network Function Virtualization
VNF Virtual Network Function
NF Network Function
NFVI Network Function Virtualization Infrastructure
OSS Operation Support System
BSS Business Support System
E2E End to End
SLA Service Level Agreement
PoC Proof of Concept
SID Information framework
SQM Service Quality Metrics
IT Information Technology
ETSI European Telecommunications Standards Institute
TMF Telecommunications Management Forum
IETF Internet Engineering Task Force
NFV-MANO Network Function Virtualization- Management and
Orchestration
EMS Element Management System
VM Virtual Machine
VN Virtual Network
TcaaS Technology component as a Service
SoC Separation of Concern
CAPEX Capital Expenditure
OPEX Operational Expenditure
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TABLE OF CONTENTS ABSTRACT ...........................................................................................................................................I
ACKNOWLEDGEMENTS ................................................................................................................ II
ABBREVATIONS ............................................................................................................................. III
TABLE OF CONTENTS ................................................................................................................... IV
LIST OF FIGURES ............................................................................................................................. V
LIST OF TABLES .............................................................................................................................. VI
3.3.1 Virtual Machine Service Quality Metrics ....................................................................... 16 3.3.2 Virtual Network Service Quality Metrics ........................................................................ 17 3.3.3 Technology Component Service Quality Metrics ............................................................ 17 3.3.4 Orchestration Service Quality Metrics ........................................................................... 17
3.4 NETWORK SLICING ........................................................................................................ 17 3.5 SERVICE ROLES AND RELATIONSHIPS ...................................................................... 18 3.6 SERVICE LEVEL AGREEMENTS ................................................................................... 18 3.7 SERVICE FUNCTION CHAINING ................................................................................... 19
Figure 1: High-level NFV framework ................................................................................... 13 Figure 2: BSS, 0SS and NFV top down framework ............................................................... 15 Figure 3: NFV Infrastructure and its initial relationship to OSS/BSS Systems ..................... 16 Figure 4: Network slices from different industries ................................................................ 18 Figure 5: Separation of Concern for performance factors in CN services and infrastructures
........................................................................................................................................ 20 Figure 6: Service levels relationship model ............................................................................ 24 Figure 7a: PoC for modelling a service requested by customer ............................................. 27
Figure 7b: PoC for delivering a service after modelling ........................................................ 27 Figure 8: Roles relationship .................................................................................................... 29 Figure 9a: PoC for reconstructing the service when customer requests for technical support
Figure 9b: PoC for delivering the reconstructed service ........................................................ 30
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LIST OF TABLES
Table 1: Table displaying the list of contributors for each section in this document ............. 10 Table 2: Interpretation of lean in to service deployment ........................................................ 22 Table 3: Mapping lean principles to PoC ............................................................................... 33
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1 INTRODUCTION Modern telecom networks are incorporated with different variety of hardware
appliances. To launch a new network service or to reconfigure a network service
which is already established yet requires another variety of hardware and finding the
space and power to accommodate these hardware is becoming ambitious
compounded by increasing costs of energy, capital investment challenges and the
rarity of skills necessary to design, integrate and operate increasingly complex
hardware-based appliances [1]. The hardware appliances reach end of life as the
innovation cycle accelerates which is also served to be reason for the evolution of
virtualization technologies.
Network Function (NF) is a functional block that is present within a network
infrastructure which has a well-defined interfaces and well-defined functional
behavior [2]. In today’s world, network function is often termed as a network node
or a physical appliance. The network function is a connection point or an end point
in a distributed network routes which can store, receive and forward data among
different routes. Network functions are engineered or programmed to recognize,
process and forward transmission to another network routes. Network functions
came in to existence with the use of packet switching and distributed networks. Some
examples of network functions include forwarding, storing, transmission,
translating, logging, distributing etc., The network elements which are responsible
for carrying these network functions include routers, switches, load balancers,
firewalls, hubs etc., In order to reduce the hardware appliances, the business
organizations are transforming these physical network functions in to software or
virtualized network functions using Network Function Virtualization technology.
Network Function Virtualization (NFV) is one of the key enabling technologies
to centralize many network equipment types onto industry standard high volume
servers, switches and storage which can be located in any data centers, network node
or any end user premises [1]. For providing faster network services, the
Communication Service Providers have commenced on to transformation of their
network infrastructure by endorsing Network Function Virtualization (NFV). The
world’s leading telecom operators have initiated NFV Industry Specification Group
(ISG) at ETSI to achieve a consistent and common architecture for the hardware and
software infrastructure needed to support Virtualized Network Functions. Network
Function Virtualization (NFV) has been introduced in the recent years into the area
of Telecom industry by the principle of separating network functions from the
hardware systems they run on by and deploying them as software on standardized
hardware systems, called as Virtualized Network Functions (VNFs) [3]. NFV and
VNF are very often interchangeable as both focuses on optimizing the network
services. Network function virtualization is an emerging technology and its
orchestration and management are really not defined. Network function
virtualization services that need to be offered to customer using virtual network
functions are to be managed. The service quality delivered by a Virtual Network
Function (VNF) service to a customer depends on the service quality of the compute,
storage and network resources offered by the NFVI. OpenStack NFV uses cloud
virtualization to compose, deploy, chain and manage standard Virtual Network
Functions running on generic physical infrastructure. In order for VNF to perform
correctly in a cloud world, the NFVI needs to provide a certain number of
functionalities which range from scheduling to networking and from orchestration
to monitoring capacities.
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Operational Support System (OSS) focuses on the status of the operation, i.e.
on a set of programs that help communications service provider (CSP) to control,
monitor, analyze and manage the network [4]. A true customer centric OSS requires
total service quality management and complete integration at the network layer.
Business Support System (BSS) handles the business interfacing with customer or
end-user [5]. They are used to support various end-to-end telecommunications
services like billing, order management, call center automation, or other customer
facing activities such as complain handling, e.g. if the service doesn’t meet the
quality expectations.
MOTIVATION: NFV aims to revolutionize the telecommunication industries by
reducing the CAPEX, OPEX, space to accommodate vivid hardware appliances
skills to design, integrate and operate these hardware appliances [1]. It also reduces
the manpower and provides easier upgrading of an existing virtual instance of a
network function in a network service. Hence NFV proves that it can leverage the
standards of telecommunication industry by transforming them in to faster, cheaper
and efficient deployment of network services.
PROBLEM STATEMENT: Network operators aim for the new revenue earning
techniques by evolving the network service from incorporating new hardware
appliances. Hence NFV technology can reduce the amount of economic output more
than a normal physical interface network. The business relationships that construct
and contain NFV are needed to follow a standardized service flow in order to deliver
value to the customer. Hence there is need to design a service performance oriented
model which can fit in to NFV making it obvious that the model is lean.
1.1 OBJECTIVES The operation and management of a complex VNF service requires monitoring
of the service fulfillment. In detail, it needs monitoring the quality of the VNF
service, i.e. an outside view, as well as there is a need to know what’s going on with
the virtualization infrastructure, i.e. inside view. The main objective of this thesis
earlier was to design a Meta data structure including interfaces that can be used for
specification, monitoring and analysis of SLAs for E2E services using VNFs. But,
in order to model a Meta data structure, the roles and their relationships needs to be
researched in depth as in order to design a structure, the information required to start
with it needs to be collected which has become the aim of this thesis later on.
Hence, the aim of this thesis is to provide the service relationships between
service provider, customer and user in order to validate the model with a proof of
concept as one view and applying the lean principles to this proof of concept to
optimize the performance is another view. The objective of thesis is to provide a
service relationships and to propose Proof of Concept (PoC) for NFV network slice
as a service. In addition, ways to describe a network function inherited from lean
principles are provided.
The main objectives of this thesis, in order to achieve the main goal on
constructing a service relationship model, are as follows:
To provide an overview of SLA and SID.
Identification of the network functions service quality metrics (SQM) and the
integrations between the network functions.
Making a requirement analysis for information model.
Service Function Chaining within the business level, service-fulfillment level,
and service session level.
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Construction and Modeling of a service relationship model which traverse a
Service Function Chain.
Performing a proof of concept for NFV network slice as a service for the service
relationship model constructed.
Applying lean manufacturing for the service relationship model.
Investigate how lean manufacturing benefits proposed service relationship
model.
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1.2 RESEARCH QUESTIONS A few research questions framed for this thesis are stated in this section, which
are answered by defining roles relationship model.
1 How do the service relationships model for NFV infrastructure benefits by lean
manufacturing?
2 What are the sufficient ways to describe network functions in the service
relationships model by lean manufacturing?
3 Which extent does a customer need to monitor about the service delivered in
the network in terms of relationships for a lean provisioning?
1.3 THESIS OUTLINE This thesis document is organized as mentioned below:
Chapter 1 provides an overview about how network function virtualization
evolved as one of the key enabling technologies. The main problem with NFV
services that are to be offered to customer using virtual network functions are to be
managed is discussed by exposing the view by how OSS/BSS supports the
telecommunication services. The objectives and aims of this thesis in order to
construct a service relationship model are classified. The research questions framed
from this problem context are included in this section.
Chapter 2 is literature research done on previous related works in the area of
NFV and service management models, and business roles.
Chapter 3 depicts the concepts and techniques such as NFVI, NFV service
quality metrics, network slicing, OSS/BSS, service relationships, service chaining
which are required for service design in NFV.
Chapter 4 depicts the methodologies such as lean manufacturing and
requirements analysis that are used to design a service relationship model for the
NFVI and to optimize its performance.
Chapter 5 contains results obtained from methodological proposition of model
with proof of concept having a detailed analysis of how to design a service of
network functions for NFVI.
Chapter 6 gives a conclusion obtained from results and detailed analysis. This
chapter motivates the conclusion statement that is derived from results. It also
contains the future work which can be implemented practically in terms of
scalability.
1.4 SPLIT OF WORK This section provides details about the contributions of work in this document
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SECTION TOPIC CONTRIBUTOR
1 Introduction Sasank Sai Sujan Adapa
Saiphani Krishna Priyanka Kolluri
1.1 Objectives Sasank Sai Sujan Adapa
1.2 Research Questions Sasank Sai Sujan Adapa
1.3 Thesis Outline Sasank Sai Sujan Adapa
2 Related work Sasank Sai Sujan Adapa
Saiphani Krishna Priyanka Kolluri
3.1
3.2
3.4
NFV Architectural Framework
OSS/BSS
Network Slicing
Sasank Sai Sujan Adapa
3.3
3.5
3.6
3.7
NFV Service Quality Metrics
Service Roles and Relationships
Service Level Agreements
Service Function Chaining
Saiphani Krishna Priyanka Kolluri
4 Methodologies used Sasank Sai Sujan Adapa
Saiphani Krishna Priyanka Kolluri
5.1 Common results Sasank Sai Sujan Adapa
Saiphani Krishna Priyanka Kolluri
5.2 Individual results Sasank Sai Sujan Adapa
6 Conclusion and future work Sasank Sai Sujan Adapa
Saiphani Krishna Priyanka Kolluri
Table 1: Table displaying the list of contributors for each section in this document
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2 RELATED WORK The literature research done is prior to design the service relationships model
and to gain knowledge concerning the NFVI, SLAs and service roles and their
relationships.
In reference [1], the authors explained how the networks are getting over
populated with large and increasing variety of proprietary hardware appliances
besides discussing about what requirements does the network operators need to have
to launch a new service. They explained a basic purpose of NFV how it aims and
benefits to transform the way that network operators architect networks by evolving
the standard IT virtualization technology. This ETSI white paper further provided
the knowledge about NFV and how to overcome the challenges faced in order to
implement NFV that there is a certain need to be addressed by the community
interested in accelerating progress.
In reference [2], the authors explained about NFVI which is totality of the
hardware and software components that build up the environment in which VNFs
are deployed. This ETSI paper defines about how the management and orchestration
block operates, automates and manages the distributed NFVI. This paper provided
with the knowledge of the NFVI and the components involved in it which is served
as an advantage for applying the NFV network slice as a service to the designed
service relationship model.
In reference [6], the authors explained about the objectives of the NFVI besides
provided a NFV reference architectural framework and identification of NFVI
domains. This further explained about the cloud service definitions (X as a service).
It helped us in understanding about different service providers present in cloud
network in order to efficiently drive the standardization between the services and
produce an efficient service.
In reference [7], the authors explained about the service quality metrics for
NFVI, management and orchestration service qualities that impact the end user
service qualities delivered by VNF instances deployed on NFVI. This helped us to
investigate further how the NFV management and orchestration can also present
subtle risks to VNF service quality if elastic resource growth or repair is slow or
faulty.
In reference [8], the authors explained about service and customer domains.
This TMF paper further explained its view towards the key characteristics or
concepts for current frameworx and component frameworx. The business process
framework, information framework and application framework explained in this
reference paper helped in categorizing the activities in the business level and service
levels.
In reference [9], the authors explained about the agreements, its characteristics
and also its terms and conditions. This paper gives a detail description about the
service level agreements and their types which helped in understanding the business
relationships and entities that make up the aggregate business agreements. This is
helpful in designing the service relationship model up to some extent.
In reference [10], the authors explained about the service chaining concept, its
use and also about how it enables operators to create services using the VNFs. This
white paper helped in figuring out the service relationships between service provider
and customer in the form of service chain.
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In reference [11], the authors explained a generic management service model
and defined the service related terms and concepts and structuring rules for designing
the model. This research paper helped in understanding few service related concepts
which helped in developing the service relationship model.
In reference [12], the authors explained in detail about the services and the roles
associated with the services in the cloud infrastructure. This paper helped us in
outlining the service provider and customer roles and their relationships.
In reference [13], the authors explained about the network functions, network
slice and the purpose of NFV. The author also gave an example of the network slices
in the evolved packet core which helped us in understanding about the network slice
and also about the components in it.
In reference [14], the authors explained about how the lean manufacturing
principles does reduce the waste of company and the removal of no value added
systems so as to bring valuable time deliverances. The authors distinguished the
wastes in to three certain categories which are to be considered when a large scale
company is managed to get efficient deliverance.
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3 CONCEPTS AND TECHNIQUES The basic concepts required for this thesis are NFV architecture, NFVI, NFV-
MANO, OSS/BSS, network slicing, business roles, service relationships, service
function chaining, and service roles relationships. In order to build a performance
oriented service model, the need to understand about the service model, its entities,
requirements and functions is very important. The techniques that are involved is to
frame a design how the business roles are related to each other and in what way do
we need to interpret them in service deployment such that we can make the
relationship fits for our model.
3.1 NFV ARCHITECTURAL FRAMEWORK In non-virtualized networks the network functions are implemented as they are
combined with specific software and hardware which are referred as network
elements. NFV is a step forward for the stakeholders in telecommunication network.
NFV introduces different changes in the service provisioning from present such as
decoupling software from hardware, flexible network function deployment, and
dynamic operation. Network Function Virtualization confronts the implementation
on top of network function as only software entities that run over the Network
Function Virtualization Infrastructure (NFVI) [15]. Figure.1 depicts a high-level
NFV framework.
Figure 1: High-level NFV framework [15]
The three main components identified in NFV are:
3.1.1 Virtualized Network Function (VNF) It refers to implementation of a network function that can be deployed on NFVI
using software that is decoupled from the underlying software. A VNF is a
virtualization of network function in a legacy non-virtualized network. The VNF is
a virtualized form of PNF (Physical Network Function). Example of NFs are Domain
Name Server (DNS), Dynamic Host Configuration Protocol (DHCP) servers,
firewalls, etc., [15]. The functional behavior of PNF and VNF are expected to be
same and independent with the state of them as virtualized or non-virtualized.
However, the whole VNF can be deployed in multiple VMs or in single VM as well.
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EMS which are located above VNFs as shown in figure.3, a single or multiple VNFs
are monitored by Element Management System (EMS). EMS are those whose
typical functionality is to manage and maintain the VNFs assigned.
3.1.2 NFV Infrastructure (NFVI) It is the totality of all hardware and software components that build up the
environment in which VNFs are deployed [2]. NFV Infrastructure is also known as
SID in TM Forum organization.
3.1.2.1 Hardware Resources
The hardware resources include computing, storage and network physical
network elements. Computing hardware is commercial of the shelf as it opposes the
purpose to build software. Storage hardware can be distinguished in to storages that
resides on the server and the storages that are shared. Network hardware include
routers, wired or wireless links [15].
3.1.2.2 Virtualization Layer and Virtualized Resources
The virtualization layer abstracts the hardware resources and decouples the
VNF software from underlying hardware ensuring a hardware independent life cycle
which can be deployed on different physical hardware resources [15].
3.1.3 NFV Management and Orchestration (NFV-MANO) It contains functions collectively provided by VIM, VNFM, and NFVO.
3.1.3.1 Virtualized Infrastructure Manager (VIM)
It is responsible for controlling and managing NFVI compute, storage and
network resources within one operator’s infrastructure domain. It can be also
possible to deploy multiple VIM instances. As per the hardware resources mentioned