1.
INTRODUCTION:
Internet is today
the most important information exchange means that is providing to the society
the mechanisms to create new forms of social, political and economical
intercourse, which is now today designing the society of the 21st Century.
Internet will be the key enabler for the free movement of knowledge in addition
to the free movement of persons, capital, services and goods. As such the
Internet plays a crucial role in the ability of humans to communicate but at
the same time opens new challenging problems. As the current Internet grows
beyond its original expectations (a result of increasing demand for
performance, availability, security, and reliability) and beyond its original
design objectives, it progressively reaches a set of fundamental technological
limits and is impacted by operational limitations imposed by its architecture.
2.
INTERNET ARCHIETECTURE
The
Internet's architecture is described in its name, a short from of the compound
word "inter-networking". The Internet architecture, the grand plan
behind the TCP/IP protocol suite, was developed and tested in the late 1970s by
a small group of network researchers.
Several
important features were added to the architecture during the early 1980's sub netting, autonomous systems, and the domain
name system. More recently, IP multicasting has been added. TCP/IP is enabled end-to-end, so that any node
on the Internet has the near magical ability to communicate with any other no
matter where they are. This openness of design has enabled the Internet
architecture to grow to a global scale.
The Internet architecture has been
successful so far in allowing a worldwide scale global internet work, being an heterogeneous collection of interconnected systems that
can be used for communication of many different types between any interested
parties connected to it. The Internet architecture is progressively losing its
original simplicity and transparency. One of the main causes is the emergence
of new classes of applications, additional operational and management
requirements, and variety of business models, security mechanisms and
scalability enablers that give rise to point solutions that extend the
architecture without regard to the original key design principles. While it is
necessary to operate the Internet under current Social, Political, Economical,
and Technical (SPET) conditions.
The combination
of these mechanisms has significantly reduced the potential for incremental
evolution of the Internet architecture. This loss of flexibility is already
being felt as the number of Internet nodes grows another order of magnitude.
Indeed, the Internet nowadays size and scope render the deployment of new
network technologies difficult while experiencing increasing demand in terms of
connectivity and capacity.
What we are
talking about?
•
We do not talk about:
§ 
Society
§ Politics
§ Economy
§ Technology
•
But:
§ How can the basic architecture can support
SPET?
§ At least as good as TCP/IP
§ Replace the traditional protocol layering
paradigm with a more general model
3.
REVIEW ON CURRENT INTERNET ARCHIETECTURE
Today’s Internet
was designed in the 1970s for purposes quite unlike today's heterogeneous
application needs and user expectations. Though the Internet infrastructure has
evolved with changing applications, its underlying architecture has to date
slowly evolved. This underlying architecture was not created to function as a
global critical infrastructure, and it has a number of fundamental limitations:
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Security
|
The lack of security
in the Internet is worrisome to everyone including users, application
developers, and network and service operators.
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Scalability
|
Questions
remain regarding the scalability of some parts of the current Internet
architecture, e. g., the routing system.
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Mobility
|
Currently,
application developers find little support for new mobile applications
and services.
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Reliability
and Availability
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ISPs face the
task of providing a service which meets user expectations of the Internet’s
crucial role in both business and private life, in terms of reliability,
resilience, and availability, when compared, for example, to the telephone
network (five nines1). Furthermore, the service has to be seamless.
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Quality of
Service
|
It is still unclear how and where to
integrate different levels of quality of service into the architecture. It is
well know since decades that "tight coupling" hinders
maintainability and enhancements of software systems that is, most of the
protocols (e.g., TCP/IP) are currently inbuilt with mostly available
Operating Systems and networking software and drivers.
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|
Problem
analysis
|
The toolset for
debugging the Internet is limited, e. g., tools for root cause
analysis.
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Economics
|
Besides these
more technical questions, there is also the question of how network and
service operators can continue to make a profit.
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CURRENT INTERNET
DESIGN GOALS, PRINCIPLES AND CHALLENGES
Why it is
difficult to address the above challenges within the current Internet
architecture we need to briefly review how the current Internet works.
The design
goals underlying the current Internet architecture in order of importance
is:
1. To connect existing networks,
2. Survivability,
3. To support multiple types of services,
4. To accommodate a variety of physical networks,
5. To allow distributed management,
6. To be cost effective,
7.
To allow host attachment
with a low level of effort and,
8. To allow resource accountability.
To achieve the
Internet design objectives, the following design principles have been used in
the current Internet:
a. Layering,
b. Packet switching,
c. A network of collaborating networks,
d. Intelligent end-systems end-to-end argument.
e. Simplicity Principle
We review how
these design principles enable today’s Internet to fulfill most of the design
goals laid out above.
(a)
Layering
The use of
network layers, leads to a network stack and offers a reduction in complexity,
isolation of functionality, and a way to structure their network protocol
designs. Each layer in the network stack offers a service to the next layer up
in the stack. It implements this service using the services offered by the
layer below. This results in a situation where the logical communication
happens within each layer. Yet during actual communication, the data passes the
network stack at the sender from the top to the bottom and at the receiver from
the bottom to the top.
(d) Intelligent end-systems / the end-to-end
argument:
The fact that the
network layer can simply drop packets is a result of keeping the network dumb
and placing the intelligence at the end-system. Should the application require
reliable data transfer, then it is the responsibility of the end-system to
provide the service, e. g., in the transport layer via TCP. Indeed, the
end-to-end argument can be used as a way to place functionality. There are two
reasons to place functionality inside the network rather than at the
end-systems: if all applications need it, or if a large number of applications
benefit from an increase in performance. This is not the case for reliability.
Not all applications require it, e. g., VoIP, and applications often have to
implement end-to-end reliability anyhow, e. g., the domain name system (DNS).
Accordingly, both packet switching and the end-to-end argument, help to ensure
survivability (design goal 1) and cost effectiveness (design goal 5).
(e) Simplicity principle (Occam's razor
principle):
This is also known as the Keep It Simple Stupid
(KISS) principle. When applied to packet network architectures, fundamental
motivation of this design principle has been enounced by J. Doyle “The
evolution of protocols can lead to a robustness/complexity/fragility spiral
where complexity added for robustness also adds new fragilities, which in turn
leads to new and thus spiraling complexities".
The original
Internet design principles ensure that the Internet fulfills most of the
original Internet design goals (0-5). The other design goals have been
addressed by crutches such as DHCP (design goal 6) or the simple network
management protocol (SNMP) and NetFlow2 (design goal 7).
4. FOUNDATION AND PILLARS OF
FUTURE INTERNET:
Future Internet is designed to accommodate
conflicting interests (the so called “tussle networking” introduced D.Clark)
such as conflicting policies, traffic patterns and
compensation modes. It is fundamental to
recognize the powerful capability of the current Internet to accommodate new
applications developed by an increasing user community. The Future Internet
shall thus ultivate the opportunity for new players to take benefit of the
infrastructure foundation but also the pillars of the Future Internet without
sacrificing on its global architecture objectives and principles.
4.1 Foundation:
The foundation of
Future Internet is a “Network Infrastructure”. The main domains of improvement
for the network infrastructure relate to its functionality (in particular, in
terms of accountability, security/privacy/trust, manageability and diagnosability,
availability, as well as mobility) and its architectural properties (in
particular the flexibility, evolvability. resiliency/survivability, and routing
system scalability), acknowledge that such improvements requires in-depth
investigation of the underlying Internet design principles and components.
Considering the
multifaceted requirements facing the Future Internet, individual demands should
be fulfilled enjoying the scale and scope effects following from a common
network. The functional properties of the FI shall include:
§ Accountability
§ Security
§ Privacy
§ Availability (maintainability and
reliability)
§
Manageability, and
diagnosability (root cause detection and analysis)
§ Mobility, and nomadicity
§ Accessibility
§ Openness
§
Transparency (the
end-user/application is only concerned with the end-to-end service, in the
current Internet this service is the connectivity)
§ Neutrality
4.2 Challenges
associated to Network Infrastructure Foundation:
The fundamental
technological challenge for the Future Internet is to be able to tackle the
question on where to place the additional capabilities including intelligence
and processing capacity and at which level to realize them.
§
Routing and addressing
scalability and dynamics
§
Resource and
data/traffic manageability and diagnosability
§
Security, privacy,
trust, and accountability
§ Accountability
§
Availability, ubiquity,
and simplicity
§ Adaptability heterogeneous environments
4.3 Pillars
of Future Internet:
The main vectors
to growth of the Future Internet referred to as pillars. These pillars are
supported by the Network infrastructure foundation as depicted in Fig. support
and sustain growth of these pillars, the Network infrastructure foundation must
itself be the object of specific research resulting from large set of technological
challenges associated to the network infrastructure
4.3.1 Internet
by and for People:
The future
Internet should be able to interconnect growing population over time. The FI
shall be capable to meet new and common people (Internet users) expectations
and needs while promoting their continuous empowerment, preserving their self
arbitration (control over their online activities) and sustaining free
exchanges of ideas. The FI shall also provide the means to
o
Facilitate everyday life
of people, communities and organizations,
o
Allow the creation of
any type of business regardless of their size, domain and technology, and
o
Break the
barriers/boundaries between information producer and information consumer.
Content creation
no longer requires professional expertise and content submission has been
tremendously facilitated by a broad variety of tools which enable users to
create high-quality content within minutes and at almost no expense.
Distributed knowledge can thus be shared easily and opinions can be made public
in almost real-time. Complemented with Social Networks, which allows
establishing and maintaining personal networks beyond any frontier, humankind
is offered an unprecedented level of interactivity. This trend combined with
the evolution of the Web has induced a new phenomenon: formation of virtual
communities and access to their wisdom that allows users to become part of the
application development life cycle. In Web 3.0, semantic technologies,
knowledge exchange, processing and generation by machines are substantial for
the Future Internet. Such intelligent methods for knowledge collection
processing and presentation are mandatory for being able to handle and benefit
from the huge amount of information being available now or in future. This
immediately leads to the second pillar, the Internet of Contents and Knowledge.
4.3.2 Internet
of Contents and Knowledge:
Digital
communication with the evolving role(s) of a cognitive society goes beyond
information and content accumulation by involving conscious intellectual
activity (as thinking, learning, reasoning, or remembering). For this purpose,
the Internet should support mechanisms for knowledge dissemination both at
local and global level. In this perspective, the way of managing the networked
knowledge needs to be revised to meet user expectations. Knowledge and culture
must be diffused worldwide to breakdown barriers and to promote dissemination
and learning.
Web evolution to
Web 3.0, will introduce cognitive intelligence, enabling Web applications not
only to provide but also to intelligently process information. Semantically
tagged information is the foundation for this new form of intelligent
capabilities: deriving knowledge from mere information and making knowledge
accessible for humans and machines including the objects of the Internet of
Things. The general capabilities of semantic descriptions also cover functional
and none-functional properties of services. The Future Internet will not only
support intelligent content and provide tools for processing information
intelligently; it will probably most importantly render it intelligibly (have
it easy understood and accessible by human beings).
4.3.3 Internet
of Things:
The expression
“Internet of Things” (IoT) recalls scenarios from science fiction, where
objects will become “living beings” and have identifiable behaviors and
actions. In the foreseeable future, we can expect that any object will have a
unique way of identification; not only, as today, computers, printers,
actuators, mobile phones, but literally any thing around us, anywhere, at any
time, creating an universally addressable continuum. Having the capacity of
addressing each other and verifying their identities, all these objects will be
able to exchange and, if necessary, actively process information according to
predefined schemes, which may or may not be deterministic. In the definition of
“Internet of Things”, the term “Thing” refers to “an object not precisely
identifiable". Hence, the “Internet of Things” can be defined as “a world-wide
network of uniquely addressable and interconnected objects, based on standard
communication protocols”.
While the current
Internet is a collection of rather uniform devices, though heterogeneous in
some capabilities but very similar for what concerns purpose and properties, it
is to be expected that the IoT will exhibit a much higher level of
heterogeneity, as objects of totally different in terms of functionality,
technology and application fields will belong to the same communication
environment. Semantics of messages will also play a central role: not all
objects will have “something to say” to other objects. As the communication
means will be the same, novel protocols based on the semantic of the language
must be developed, if the IoT will have to scale to the zillions of objects
around us.
Moreover, humans
can integrate seamlessly into such a smart environment and become active part
in the definition of their instantaneous context, which, for example, closes
the digital patient physician loop enabling novel applications in the future
healthcare industry (including ageing). Finally, any object connected either
offers a service or requires the existence of one or many services. Hence,
there is a natural and close relation to the other novel view of the Future
Internet, the Internet of Services.
4.3.4 Internet
of Services:
The term Internet
of Services is an umbrella term to describe several interacting phenomena that
will shape the future of how services are provided and operated on the
Internet. Three major domains of development are the emergence of
Internet-scale service oriented computing, the contextualized and proactive
services and service orchestration.
o
The emergence of
Internet-scale service oriented computing: Service oriented computing has gained increasing
attention in recent years as the next evolutionary step after component-based
software. An important concept in that context is that of “loose coupling”.
Whereas electronic interaction in the Internet is mostly based on the use of
tight properties – like IP addresses of physical machines or data sources – a
service-oriented Internet would allow the access to complex physical compute
resources, data or software functionality in the form of services.
o
Contextualized,
proactive, and personalized access to services: The Internet of Services will allow proactive and not
only reactive services as currently enabled on today’s Internet. At the same
time, it will empower people to personalize their experience. The concept
“context-awareness” meaning that interaction will become fully personalized and
suited to the context in its widest meaning (including user preferences, usage
history or the social networks users belong to and the delivery context, which
in turn comprises access device description, location and time). This links to
the technical possibilities of “loose coupling”, as services can be flexibly
detected and invoked based e.g. on semantically rich inference rules relying on
properties describing context.
o
Service orchestration and the rise of core services: Already in
the current Internet we are using some core services – such as search engines.
Others, e.g., to provide geo-information, people search or social networking
have seen tremendous growth in recent years. This is even more the case in
business scenarios where complex services from different providers are
combined, e.g., to link the management of customer data to advanced data
mining, geo-economic information, sales reporting, and life market trends. As a
consequence of this stronger linkage of services, some services will become
fundamental and shared by many derived services. The Internet of Services will
therefore emerge in several layers of services, from fundamental infrastructure
services – like those provided by clouds to specific, data-, information-,
application-like and user interfacing services.
4.4 Challenges associated to Pillars:
The
challenges will apply to the different pillars. As a summary of some of the
most urgent challenges, the following can be highlighted:
§
Internet
by and for People:
Among
the activities related to increase the knowledge of the user, learning their
habits and needs to better design future applications, interfaces and services
while keeping people self-arbitration and mindful is a major area of
investigation. This includes research challenges in the following areas:
o
Knowledge of
users.
o
Content and
user awareness
o
Active users
o
User
experience
§
Internet
of Contents and Knowledge:
This
broad area relates to the generation and processing of content and the
transformation to that content into useful information. It also includes the
aspects regarding the user and its characterization and relationships between
user and content. In this area, the main challenges are:
o
Digital
Content
o
Distributed
Media Applications
o
New User
Devices and Terminals
§
Internet
of Things:
The
challenge is to handle the large amount of information coming from the things
and to combine it to give useful services. As the current network structure is
not suited for this exponential traffic growth, there is a need by all the
actors to re-think current networking and storage architectures. It will be
imperative to find novel ways and mechanisms to find, fetch, and transmit data.
Distributed, loosely coupled, ad-hoc peer-to-peer architectures connecting
smart devices might represent the network of the future. In this context the
following elements require specific attention:
o
Discovery of
sensor data — in time and space
o Communication of sensor data:
Complex Queries (synchronous), Publish/Subscribe (asynchronous)
o
Processing
of great variety of sensor data streams
o In-network processing of sensor
data: correlation, aggregation, filtering.
Non-technological
challenges shall also be recognized in the context of the Internet of Things:
o
“Digital
divide between things”
o
Governance
§
Internet
of Services:
Service
"consumers" look for the perfect interactivity in context. With
“perfect” we mean here permanent (i.e. interactivity that has no time limits),
direct (i.e. the service consumer is only concentrated on the benefits of the
service he/she is using), seamless (i.e. the interaction is performed using the
“typical” devices of the context), and confident. The
term services would include a broad variety of applications that will run over
a service-aware made up of elements for which further research is needed:
o
Cloud
computing
o
Open Service
Platforms
o
Autonomic
computing
o
Green IT
5. COMPARISON OF LAYERED VS.
SERVICE-ORIENTED APPROACHES
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In terms of
|
Traditional-layered Approaches
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Service-Oriented Approaches
|
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Modularity
|
Several
functionalities per protocol unit.
One header per
protocol with interrelated data.
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Functional spec
of a communication building block.
One header per
functionality.
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Processing order
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Sequential per
layer.
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Arbitrary graphs.
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Explicit/Implicit
|
Explicitly name
protocol.
Implicitly
associate data structure and processing rules.
Explicitly add
options.
|
Explicitly name
functionality and data structure.
Explicitly add
optional data.
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6. CLEAN SLATE APPROACH:
In this approach, the system is redesigned from scratch to
offer improved abstractions and/or performance, while providing similar
functionality based on new core principles. This approach works from
clean-slate to eliminate legacy Internet design constraints.
o
Define a new Internet
architecture from scratch that would provide for a better global solution
(addressing Future Internet challenges as a bundle)
o
Disruptive innovation
not impacted by existing install base/technologies
o
Feasibility in the
context of large-scale experimental facilities
o
Development of new
networking concepts that will arise from the perspectives of new business
models, service architectures, application procedures and new technology
implementations.
7. CONCLUSION:
Many believe that
it is impossible to resolve the challenges facing today’s Internet without
rethinking the fundamental assumptions and design decisions underlying its
current architecture. Therefore, a major research effort has been initiated on
the topic of Clean Slate Design of the Internet’s architecture. Through this
paper we first give an overview of the challenges that a future Internet has to
address and then discuss approaches for finding possible solutions, including
Clean Slate Design. Next, we discuss how such solutions can be evaluated and
how they can be retrofitted into the current Internet.
8. REFERENCES:
1. Fundamental design issues for Future
Internet, Scott Shenker, IEEE Member, IEEE Journal on Selected area in
Communication Vol.13 No. 7 September 1995
2. K. F. D. Meyer, L. Zhang. “RFC 4984: IETF
report” from the IAB Workshop on Routing and Addressing, September 2007.
3. Cerf, V. and R. Kahn, "A Protocol for
Packet Network Intercommunication," IEEE Transactions on Communication,
May 1974.
4.
Clark, D., Sollins, K., Wroclawski, J., and Faber, T.,
"Addressing Reality: An Architectural Response to Real-World Demands on
the Evolving Internet." ACM SIGCOMM 2003 FDNA Workshop, Karlsruhe, August
2003
5.
Xiaowai Yang, "NIRA: A
New Internet Routing Architecture". ACM SIGCOMM
FDNA 2003 Workshop, Karlsruhe, August 2003.
6. Future Internet
Symposium 2008, http://www.fis2008.org/
7.
“Developing a
Next-Generation Internet Architecture” Robert Braden, David Clark, Scott
Shenker, and John Wroclawski July 15, 2000 http://www.isi.edu/newarch/DOCUMENTS/WhitePaper.pdf
8. R. Braden, D. Clark, S. Shenker, “Integrated
Services in the Internet Architecture”. Network Working Group RFC-1633, June
1994.
9. S. Kent and R. Atkinson, “Security Architecture for the Internet Protocol”.
Network Working Group RFC-2401, November 1998.
10. R. Dutta, G.N. Rouskas, I. Baldine, A.
Bragg, D. Stevenson: “The SILO Architecture for Services Integration, controL,
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Communications, ICC apos 2007.