ISO/IEC TR 29181-7:2013

TECHNICAL ISO/IEC
REPORT TR
29181-7
First edition
2013-04-15
Information technology — Future
Network — Problem statement and
requirements —
Part 7:
Service composition
Technologies de l'information — Réseaux du futur — Énoncé du
problème et exigences —
Partie 7: Composition des services

Reference number
©
ISO/IEC 2013
©  ISO/IEC 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any
means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission.
Permission can be requested from either ISO at the address below or ISO’s member body in the country of the requester.
ISO copyright office
Case postale 56  CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO/IEC 2013 – All rights reserved

Contents Page
Foreword . iv
Introduction . v
1  Scope . 1
2  Normative references . 1
3  Terms and definitions . 1
4  Abbreviations and acronyms . 2
5  Overview . 3
6  Problem Statement . 7
6.1  General problems . 7
6.2  Scalability . 10
6.3  Dynamics . 11
6.4  Security . 11
7  Requirements of service composition for the FN . 11
7.1  General requirements . 12
7.2  Specific requirements . 13
Annex A (informative) Related standardization and research activities . 18
A.1  IEEE P1903 (NGSON) . 18
A.2  TMF Service Delivery Framework . 19
A.3  ITU-T NGN SIDE . 19
A.4  ATIS SON Forum . 20
A.5  Related research activities . 20
A.5.1  Service-Oriented Architecture (SOA) paradigm . 23
A.5.2  Service Oriented Network Architecture (SONATE) . 24
A.5.3  4WARD . 25
A.5.4  Web Service Composition . 27
A.5.5  Service Composition Approaches . 28
Annex B (informative) Technical aspects of service composition in FN . 34
B.1  A common protocol for supporting service composition . 34
B.2  Service Composition approaches . 34
B.3  Composing network functionality . 35
B.4  Composition scope and service granularity . 36
B.5  Place for composition . 36
B.6  Composition execution epochs . 37
B.7  An architecture based on services . 37
B.7.1  Composition of transport and application services . 39
B.7.2  Service identification . 40
B.7.3  Service description . 41
B.7.4  Service allocation . 42
Annex C (informative) Functional Building Block of Service Composition in FN . 43
C.1  Functional Components . 43
C.1.1  Service Manager (SR). 43
C.1.2  Service Registration Manager (SRM) . 44
C.1.3  Context Manager (CM) . 44
C.1.4  Reference Points . 45
Bibliography . 46

© ISO/IEC 2013 – All rights reserved iii

Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are members of
ISO or IEC participate in the development of International Standards through technical committees
established by the respective organization to deal with particular fields of technical activity. ISO and IEC
technical committees collaborate in fields of mutual interest. Other international organizations, governmental
and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information
technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75 % of the national bodies casting a vote.
In exceptional circumstances, when the joint technical committee has collected data of a different kind from
that which is normally published as an International Standard (“state of the art”, for example), it may decide to
publish a Technical Report. A Technical Report is entirely informative in nature and shall be subject to review
every five years in the same manner as an International Standard.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights.
ISO/IEC TR 29181-7 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 6, Telecommunications and information exchange between systems.
ISO/IEC TR 29181 consists of the following parts, under the general title Information technology — Future
Network — Problem statement and requirements:
 Part 1: Overall aspects
 Part 3: Switching and routing
 Part 4: Mobility
 Part 6: Media transport
 Part 7: Service composition
The following parts are under preparation:
 Part 2: Naming and addressing
 Part 5: Security
iv © ISO/IEC 2013 – All rights reserved

Introduction
The development of the networks during the last years has shown that it becomes harder to integrate new
functionality in order to fulfill the demands of new applications and the capabilities of new transport
technologies. Especially the core mechanisms are hard to change as it lies in a rigid and ossified architecture.
The current picture of the networks shows a large, heterogeneous, dynamic and complex distributed system.
Lots of patches aimed to amend different issues that have arisen during last years. Current networks have to
deal with new services, applications and computing paradigms such as new modes of interaction,
identification, context-awareness, energy efficiency, seamless service discovery and composition, mobility,
ubiquity, etc. At this point, current networks must look for clean solutions to known issues.
The development of a new network architecture has been discussed for some time now. Several proposals
are considered in this sense, evolutionary (incremental) approaches and revolutionary (clean-slate). Currently,
the general idea in SC6 WG7 is to standardize an architecture to solve current networks faults.
The Future Network (FN) will define a scalable, flexible and robust architecture which will aim at providing
services taking into account the changing conditions of the context and thus, offering customized
communication and seamless delivery of data. To achieve this, it is necessary to provide service composition
capabilities by means of a specific framework that will contribute to create a scalable, modular, and service-
aware FN.
The FN introduces a new architecture where the necessary functionality for establishing communications in
any node connected to the network (user devices and network elements), is not fixed but dynamically
composed, as appropriate to user service requirements, network transfer capabilities and surrounding context
in the user and the network environments. In essence, a service-oriented paradigm is followed.
Communications are accomplished by assembling appropriate atomic services, each performing a specific
communication function. As such, service functionalities can be combined to create higher level
communication services, which in turn can be combined with other services as well to enrich existing services
or to create new composed ones, until the whole spectrum of required functionality for end-user
communications is in place
Service composition is the technology that supports the composition of those activities required to reuse and
combine existing services to enrich current services and to create new services. This technology provides a
natural way of combining existing services including both atomic and composite services. Such kind of
recursive composition of composite services is one of the most attractive and challengeable features of the
service composition, allowing to rapidly and easily create new services. Thus, the service composition
provides benefits on improved usability of existing services, faster time for service creation and reduced time
to market for new services.
© ISO/IEC 2013 – All rights reserved v

TECHNICAL REPORT ISO/IEC TR 29181-7:2013(E)

Information technology — Future Network — Problem
statement and requirements —
Part 7:
Service composition
1 Scope
This part of ISO/IEC TR 29181 describes the problem statement, requirements and a functional building block
for the FN from the perspective of service composition. The goal of this part of ISO/IEC TR 29181 is to:
a) analyze and classify problems of the current solutions on the service composition,
b) identify requirements on the service composition for the FN,
c) describe some technical aspects of the service composition for the FN, and
d) propose a functional building block of the service composition including functional components and their
reference points among them.
This part of ISO/IEC TR 29181 also introduces various on-going standardization and research activities
related to service composition.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO/IEC TR 29181-1, Information technology — Future Network — Problem statement and requirements —
Part 1: Overall aspects
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC TR 29181-1 and the following
apply.
3.1
Atomic Service (AS)
well-defined and self-contained function or role commonly used in networking protocols (acknowledgments,
sequence numbers, flow control, etc.) to establish communications for consuming composite services
3.2
Atomic Mechanism (AM)
specific implementation which provides the desired atomic mechanism functionality
© ISO/IEC 2013 – All rights reserved 1

3.3
Composite Service (CS)
service that is composed of more than one atomic service
NOTE The composite service logic needs to be specified in a workflow to describe the composition and execution
process.
3.4
Service Composition Algorithm (SCA)
mechanism in charge of selecting and associating the specific atomic mechanisms which will create a
composite service, specified in the form of a workflow
3.5
Workflow (WF)
formal representation of a CS
NOTE The result of the service composition process is the definition of a set of CSs which will be executed at the
nodes involved in a communication. The atomic services are selected according to their specifications and functionalities.
Concretely, the algorithm (SCA) will generate the final CS and represented by a WF.
3.6
Patterns or templates
commonly used and well-known WF
NOTE Patterns or templates can improve and speed up the selection process carried out by the execution of SCAs in
specific cases.
4 Abbreviations and acronyms
ACCS  Auto-Configuration for Communication Security
AM  Atomic Mechanism
AS  Atomic Service
BPEL Business Process Execution Language
CBA  Component Based Architecture
CBC  Component Based Computing
CS  Composite Service
DAML  DARPA Agent Markup Language
EBS  Effective Bit Strength
HSP Heuristic Search Planner
FN  Future Network
IP  Internet Protocol
IPSec Internet Protocol Security
JSON JavaScript Object Notation
MOVE Materialized Ontology View Extractor
2 © ISO/IEC 2013 – All rights reserved

MPLS  MultiProtocol Label Switching
NAT  Network Address Translator
NGSON Next Generation Service Overlay Network
OWL  Ontology Web Language
OWL-S  Ontology Web Language for Services
PDDL  Planning Domain Definition Language
QoS  Quality of Service
RNA Recursive Network Architecture
SDF Service Delivery Framework
SIDE Service Integration Development Environment
SLA  Service Level Agreement
SOA  Service Oriented Architecture
SOAP  Simple Object Access Protocol
SON Service Oriented Network
SONATE Service Oriented Network Architecture
TCP  Transmission Control Protocol
TCS  Taxonomical Classification System
TLS  Transport Layer Security
UCPOP  Universal Conditional Partial Order Planner
UDDI  Universal Description Discovery and Integration
WSMO  Web Service Modeling Ontology
WF  Workflow
WS  Web Service
WSDL  Web Service Description Language
XML  eXtensible Markage Language
XSRL  XML Web-services Request Language
5 Overview
A service is a set of functions or tasks that provided by software or a system, usually accessible through an
application programming interface (API). Considering different types of services, a service can be classified as
an atomic service or composite service. Each atomic service provides one concrete and well-defined function.
© ISO/IEC 2013 – All rights reserved 3

Different implementations of an atomic service may exist in different nodes or co-exist in the same node. The
description information of the atomic service should be published and registered to a service registry before
providing the service functionality. On the other hand, a composite service is composed of more than one
atomic service. Each composite service implies consuming different atomic services and/or sometimes other
composite services, with possible dependences appearing between them.
Service composition is the technology that supports the composition of those activities required to reuse and
combine existing services to create new services. This technology provides a natural way of combining
existing services including both atomic and composite services. Such kind of recursive composition of
composite services is one of the most attractive and challengeable features of the service composition,
allowing to rapidly and easily create new services. Thus, the service composition provides benefits on
improved usability of existing services, faster time for service creation and reduced time to market for new
services.
Different design approaches for service composition are used in service oriented computing areas. These
approaches can be classified on user defined, semi-automatic or automatic approaches. Under this
classification, there are several design mechanisms such as template-based, instance-based, declaration-
based, workflow-based, ontology-based, AI planning-based, so on as described in Appendix A.5.5. These
design approaches allow building composite services to specify service composition suited for specific service
or business needs.
The FN introduces a new architecture where the necessary functionality for establishing communications in
any node connected to the network (user devices and network elements), is not fixed but dynamically
composed, as appropriate to user service requirements, network transfer capabilities and surrounding context
in the user and the network environments. In essence, a service-oriented paradigm is followed.
Communications are accomplished by assembling appropriate atomic services, each performing a specific
communication function. As such, service functionalities can be combined to create higher level
communication services, which in turn can be combined with other services as well to enrich existing services
or to create new composed ones, until the whole spectrum of required functionality for end-user
communications is in place.
The process of combining available services to create a desired communication service is called service
composition.
As opposed to the stringent protocol-oriented approach of current TCP-/IP based communications, the
proposed service-oriented and functionality-composed approach adopts a loosely-coupled design. As such, it
is beneficial in many aspects:
 It is flexible in building multi-feature and customized communication services
 It allows users to participate in the provision of the services they desire (e.g. user-control routing for
performance or cost reasons)
 It provides for adaptation to heterogeneous networks from the very same terminal device
 It facilitates the deployment of new network, service and/or information access technologies from
network and user access perspectives
 It avoids redundancy of functionality both in terms of duplication and unnecessary placement
The FN service composition prompts for baring user devices and smart networks. Smart networks would
equip on-the-fly with the necessary communication functionalities as appropriate to changing user needs and
requirements while, at the same time, they would choreographise themselves to deliver the requested
services at the desired quality levels.
Figure 1 illustrates a conceptual architecture of service composition in the FN that is composed by the
following functional building blocks.
4 © ISO/IEC 2013 – All rights reserved

Figure 1 — Conceptual architecture of service composition
 Services
- From the service composition perspective, services can be classified by atomic services or
composite services
- Atomic service corresponds to a base service that cannot be further decomposed and it does not
contain other services
- Composite service corresponds to a service that is composed of more than one service which
can be an atomic service or also composite service itself. It contains an execution sequence of
the composite services
- Figure 2 illustrates a possible taxonomy where services can be classified in different
arrangements such as granularity, scope, execution, usage, order, and purpose [1].
 Granularity: services can be classified as atomic or composite.
Each atomic service provides one concrete and well-defined networking function
(along with the reverse function, if any). Different algorithms and implementations of
an atomic service may exist (e.g. different congestion control algorithms), and co-
exist in the same node, using attributes to both describe the different possibilities and
to tune/configure the atomic service in order to use it to fulfill specific workflows needs.
Atomic Services will abstract specific implementations of different functionalities. The
specific implementation will be called Atomic Mechanism.
Each composed service or application implies consuming different atomic and
sometimes other composed services, with possible dependences appearing between
them. In addition, they can involve one or more nodes, depending on the complexity
of the service.
 Execution/Distribution:
Isolated: local execution of the service.
Distributed: execution distributed between two nodes, regardless their location. It
includes support for end-to-end, section and hop-by-hop distribution/allocation of
services.
© ISO/IEC 2013 – All rights reserved 5

 Scope: services can be applied with different scopes or considerations depending on
the desired result.
Network: services are executed to optimize communication according network context.
Application: services are executed to optimize application behavior and interconnection
to meet application requirements according to context characteristics.
 Usage: rules governing the service usage.
Mandatory: usage of this service is mandatory as it is basic for establishing a
communication (e.g. forwarding).
Optional: usage of this service is optional, its usage will depend on application
requirements and context characteristics.
 Purpose: which is the purpose of the service. Some examples are shown next.
Delivery: to deliver data between two different entities involved in the delivery chain
(they can be adjacent or non-adjacent nodes or they can be two end applications,
depending on the scope of the service).
Mobility: services related to application, user and node mobility.
Storage: services dealing with the storage of data.
Security: services dealing with security issues.
Data Adaptation: services dealing with adapting and transforming data for different
objectives, interoperability, customization and optimization of data.
Addressing: services dealing with the identification and labeling of resources.
Management: services dealing with the management of the different entities in the
network (nodes, applications, services, etc.).
Signaling: services dealing with interchange of signaling and control data.
Presentation: services dealing with the presentation of contents and user/application
interfaces.
 Order: order/existence of the AS in workflow composition may be dependent of another
service.
Dependent: needs the use of another AS.
Independent: no need of other AS execution.
6 © ISO/IEC 2013 – All rights reserved

Figure 2 — Service taxonomy
 Service Composition Building Block
‐ The FN architecture consists on different architectural components as building blocks that
provide a set of supporting technologies such as naming and addressing, switching and routing,
media distribution, security, and mobility
‐ Service composition is one of the architectural building block identified to support composite
services and it is composed by a set of managers such as service manager, context manager,
and service registration manager. These managers provide a set of supporting functions such as
service selection, service chaining, interpretation of composition description, service execution
monitoring, service validation, service adaptation.
‐ In the FN, both static and dynamic service composition are supported
 Network Architecture
‐ The FN supports the virtualization of different kind of resources that are spread across different
locations such as storage, computing power, processing power and network
‐ Thus, proper amount of resources can be flexibly dedicated to each atomic service and
composite service. For this purpose, the service composition building block should support some
mechanisms to coordinate virtualized resources required by composite services.
6 Problem Statement
6.1 General problems
Several challenges might be faced for designing an integral solution for the service composition in the FN that
allows to overcome the current technologies and deficiencies.
A new concept and definition of services for the FN will be closely connected to the innovation of
heterogeneous environments formed by different kind of networks and users with different requirements. The
FN design will allow adopting futuristic capabilities. Complex and personalized users’ requirements introduce
the need of networks able to be self-configurable and self-evolvable. Considering this, the service composition
technology should be also extended to cover possible changes derived from the service and network evolution.
© ISO/IEC 2013 – All rights reserved 7

New distributed software systems have become more dynamic, allowing transparent distribution, self-
reconfiguration, portability, etc. Based on that, new paradigms deviated from the end-to-end principle have
emerged, such as Pervasive and Ubiquitous Computing or the Internet of the Things.
In addition, the continuous evolution of applications and services are increasing current networks complexity,
adding more and diverse requirements (e.g. mobility, security or multihoming) that are not efficiently covered
by current TCP/IP protocol stack, as detailed in ISO/IEC TR 29181-2/3/4/5. New features such as data and
service identification, context-awareness, seamless service discovery and composition, etc. are required in
order to meet the new demanded services and modes of interaction. The lack of these features is withering as
well the evolution of networks and slowing down or stopping solutions for known open issues like mobility,
flexibility, security, etc. A service-aware architecture should help the deployment of clean-slate solutions in all
these aspects.
Nowadays, network level services are executed without taking into account the characteristics of the
surrounding context. Consequently, the current architecture fails to provide information of the underlying
network technologies, the capabilities of the devices involved in a communication or the characteristics of the
users interacting. This provokes that similar or redundant network services (e.g. error correction,
retransmission, encryption) are executed at different levels wasting computing resources, introducing
unnecessary redundancies and sometimes degrading communication performance. Furthermore, in certain
environments, the execution of certain functions can be counterproductive for the correct operation of an
application or network service (e.g. TCP’s congestion control in wireless networks), making it necessary to
modify existing protocols in order to adapt them to environments with restrictions.
This situation is mainly provoked by the rigid and layered communication stack which difficult inter-layer
communication. For example, in constrained networks, the need for efficiency in both communication and
node performance and energy consumption has led to the prevention of layering and related complex
abstractions-by fine-tuning network protocols to application requirements. These approaches result in network
architectures that are tightly coupled with the applications, and thus are application-dependent. Therefore, in
order to keep the required application-agnostic network architecture simple but flexible, as well as sufficiently
optimized, these non-layered solutions should be generalized, thereby converging in modular network
architecture able to perform optimally according to different application needs and heterogeneous node
capabilities (ISO/IEC TR 29181-1).
However, there are some problems that hindered the deployment of service composition at a macro level.
Applying service composition techniques at transport layer means a change of paradigm, which can affect the
design of the whole architecture. The inertia caused by the usage of TCP/IP stack and its ossification makes a
clean integration of service composition impossible.
Furthermore, a deployment at higher levels is becoming extremely difficult because of the lack of efficient
context- and service-aware features and the proliferation of different particular solutions that are not
interoperable between different service providers or domains.
Additionally, some scalability aspects may be taken into account, during the service identification and
composition process. Depending in which granularity the service is defined, the composition could turn in a
high complex process that can last for too much time and this would suppose an unpractical solution. In order
to find a feasible solution for service composition, tradeoffs between composition time and optimization should
be found.
Currently, services are linked to the physical entities that handle the service. That means that in current set-up,
services are addressed through network location of the server and not in a descriptive manner that permit an
efficient service discovery. That implies that the service discovery depends basically on the web search
engines that permit us do a natural search, or rely on our previous knowledge of where to find the service.
Thus, current service discovery processes have a very limited scope. This is especially true for interactive
multi-media services and applications, which can dynamically combine different media flows (audio, video,
advertisements, etc.) from a multitude of organizationally dispersed sources, content servers, cameras and
advertisement/recommendation systems.
For this reason, a shift from current convention towards a more service-oriented architecture is required.
Consequently, a generic definition of services and a standard framework to publish and discover them are
elementary needed processes. It is important that this definition would be technology and network agnostic.
8 © ISO/IEC 2013 – All rights reserved

Thus, services can be discovered and requested at a semantic level, transparently to the exact location of the
service and the underlying access and implementation technologies whilst enhancing the interoperability
between systems in all kind of environments.
In order to invoke a service available inside a network, a service request and handling mechanisms should be
provided by the FN architecture. Ideally, these processes should imply the lightest possible exchange of
information between the entities in order to maximize the throughput of networks. Solutions around this issue
in current network are performed at an application level and are not suitable as they use heavy
communication protocols based on XML (e.g. Web Service technologies). They are not efficient and they are
barely prepared for handling a service configuration setup process involving network context and QoS
parameters. Service negotiation should be enhanced, allowing users a better control of the services that they
are consuming and network administrators of service providers a better management of their resources.
Interoperability in service negotiation is a priority as well in order to find mechanisms that alleviate different
provider tensions and creating “all party win” situations [2].
A service-oriented landscape where providers can be positioned as competitive collaborators providing multi-
provider service compositions is desirable. For that reason, the lack of a negotiation protocol, able to negotiate
in-network services between different providers, is an obstacle that should be solved in the FN specification.
Furthermore, the introduction of strategies in the network that guarantee a certain level of Quality of Service
(QoS) and Quality of Experience (QoE) should be as well a critical need in the FN. Hence, both users and
providers, should explicitly specify and agree on the terms of the services that they will receive/provide.
Taking these problems into account, there are some features close related to Service Composition in the FN
that should be inherently integrated in its architecture:
 Dynamic network composition. Establishing network functions as services that can provide and
access easily to all this information should be an essential feature in the FN, in order to have a
network that can adapt to current requirements and new ones that eventually rise up. A greater
modularity of the network means a better adaptation to new communication paradigms, while
decreasing the complexity of the architecture. Unlike static service composition, services can be
specified at run time. It means that the capabilities of the service can be extended dynamically,
allowing runtime re-composition, decomposition of services, and dynamic adaptation in case of
changes in context (services and resources) involved in composite services.
 Network flexibility. Network service composition should facilitate in the FN the integration of new
functionalities into the network. Instead of tight coupling of functionalities within end-to-end protocols,
network services are deployed on arbitrary nodes, are loosely coupled and provide their service to
arbitrary other functional blocks. This design originates in the service oriented architecture approach
and requires means of service description, discovery and composition. This design approach reduces
management efforts and provides a flexible framework to integrate new network services.
 Inherent cross-layer information exchange. Cross-layer means that functionalities can be adjusted
based on the interaction between different layers. The FN should allow arbitrary composition and
information exchange between network services, thus incorporating the benefits of cross-layer design
architectures.
 Context-awareness in service composition. The FN should support the context management to
provide customized and context based services. Thus, different kind of context including user, device,
service, resource, and network can be used for discovering, selecting, allocating and composing
services to participate in the composition process.
 Requester empowerment in service choice and routing. Service requester should have more
control over the contents/service that wants to consume. This control must be reflected in flexible
routing and service selection according to requester's service definition. Consequently, the FN must
build a network architecture that provides more intelligence to the network-side whilst still leaving
decision-making processes at the end-points.
 Semantic Searches oriented to service/resource. The FN must be focused on a service/data-
centric approach that allows executing the search of services and resources based on the requester
© ISO/IEC 2013 – All rights reserved 9

requirements. This implies that future network must be able to create, discover, negotiate and
consume composite services in a flexible and context-aware way.
 Resources and services identification. Every flow over the FN must be routed based on its
requirements. Therefore, each flow must be identified in order for nodes along the route to cooperate
and negotiate autonomously, for guaranteeing the minimum QoS parameters of it.
 Environmental heterogeneity. Heterogeneity of nodes, networks and services add another level of
complexity to service composition process for the FN. If instances of a service are executed in nodes
with different capabilities and network access links, every service instance should be evaluated
individually, and attributes of a specific one could not be applied to one of another node.
 Attribute acquisition. Composition process should be based on the attributes of the services (and
their concrete implementation), but extract the complete and updated information of a service is
extremely difficult. It should require a previous empiric process extracting information about how the
inclusion of a service or another affects in terms of delay, error rate, and each QoS parameter that are
relevant for a complete solution (the whole chain of services from requester to end service provider).
 Validation and verification. When multiple service providers interact, it is important to establish trust
agreements on service validation and verification to guarantee consistency and reliability of services
in the FN in such a way that it does not hamper the entire process of the service composition. Each
service needs to be validated its correctness and consistency before registering itself with the FN.
Furthermore, the services need to be verified their behavior in terms of functionality, protocols,
availability, performance, service price, or other attributes. Moreover, the service composition output
should be validated to ensure that the selected services meet users’ expectations and, in addition,
that the network can provide the requested services. This process can be done once a composition is
performed and the output is provided (design-time or run-time). Moreover, service composition
validation will evaluate the matching between user requirements, service goals and available
resources. The output of the validation process can be a score useful for determining the degree of
quality of experience to be achieved.
 New Business Models. Internet brings opportunities to create new business models according to
novel services, applications and capabilities demanded by users. Hence, it is necessary to introduce
innovative models for costing and pricing. The FN architecture should also provide a transparent
framework that permits service consumers and providers to interact, establish agreements and satisfy
their goals. Furthermore, it will allow network providers to differentiate from competitors by offering
services and service composition possibilities at low levels inside the network and guaranteeing them
higher margins. A higher accuracy on the use of their resources and a better control of the QoS
offered in any case. Because service providers and customers can choose between the services this
will also lead to a thriving evolution of network services where the best performing and efficient
services will survive [3].
6.2 Scalability
Scalability is always a critical issue, even more considering current evolution of network technologies, types
and number of devices, number and heterogeneity of users connected to the network and amount of
information exchanged through the network. Scalability can be limited in network domains because, for
instance, the use of flooding-based mechanisms that restrict network domain size. Hence, semantic
identification will not scale well outside local domains unless some infrastructure support is provided. Besides,
clustering strategies are needed to make the semantic routing approach scalable (further detailed in ISO/IEC
TR 29181-3 for another part).
Therefore, attributes related to domains, used as labels, or identifiers to distinguish between administrative
domains and networks can be used. The main difference with current Internet scheme is that the information
used to define and label different domains is not the same as that used nowadays. Currently, network prefixes
and addresses are used. They are tightly coupled with routing protocols. Nevertheless, the FN should works
with semantic attributes to achieve such flexibility. The FN naming and addressing scheme should not be
constrained by their form and meaning as is the case of current IP addresses and domain names.
10 © ISO/IEC 2013 – All rights reserved

Hence, any type of attribute is supported and identifiers could take any form. They could be anything that
allows identifying and locating a service in a domain. As examples, service identifiers could be a geographical
(virtual or not) coordinate bounding the domain area, a random label, an IP address or other legacy/existing
addressing schemes requiring no changes in their original architecture. Using one type of attribute or another
will depend on the considered scenario and required routing information (e.g. geographical routing will require
the use of coordinates).
Thus, high scalability in structured environments could be achieved by means of service discovery that rely on
special entities providing the required infrastructure/signaling services whilst avoiding flooding. Some
approaches can be adopted such as introducing the use of a semantic resolver instead of performing
semantic flooding. The goal of a semantic resolver
...