380 research outputs found
Cost-aware caching: optimizing cache provisioning and object placement in ICN
Caching is frequently used by Internet Service Providers as a viable
technique to reduce the latency perceived by end users, while jointly
offloading network traffic. While the cache hit-ratio is generally considered
in the literature as the dominant performance metric for such type of systems,
in this paper we argue that a critical missing piece has so far been neglected.
Adopting a radically different perspective, in this paper we explicitly account
for the cost of content retrieval, i.e. the cost associated to the external
bandwidth needed by an ISP to retrieve the contents requested by its customers.
Interestingly, we discover that classical cache provisioning techniques that
maximize cache efficiency (i.e., the hit-ratio), lead to suboptimal solutions
with higher overall cost. To show this mismatch, we propose two optimization
models that either minimize the overall costs or maximize the hit-ratio,
jointly providing cache sizing, object placement and path selection. We
formulate a polynomial-time greedy algorithm to solve the two problems and
analytically prove its optimality. We provide numerical results and show that
significant cost savings are attainable via a cost-aware design
Seamless Infrastructure independent Multi Homed NEMO Handoff Using Effective and Timely IEEE 802.21 MIH triggers
Handoff performance of NEMO BS protocol with existent improvement proposals
is still not sufficient for real time and QoS-sensitive applications and
further optimizations are needed. When dealing with single homed NEMO, handoff
latency and packet loss become irreducible all optimizations included, so that
it is impossible to meet requirements of the above applications. Then, How to
combine the different Fast handoff approaches remains an open research issue
and needs more investigation. In this paper, we propose a new Infrastructure
independent handoff approach combining multihoming and intelligent
Make-Before-Break Handoff. Based on required Handoff time estimation, L2 and L3
handoffs are initiated using effective and timely MIH triggers, reducing so the
anticipation time and increasing the probability of prediction. We extend MIH
services to provide tunnel establishment and switching before link break. Thus,
the handoff is performed in background with no latency and no packet loss while
pingpong scenario is almost avoided. In addition, our proposal saves cost and
power consumption by optimizing the time of simultaneous use of multiple
interfaces. We provide also NS2 simulation experiments identifying suitable
parameter values used for estimation and validating the proposed mode
Characterizing a Meta-CDN
CDNs have reshaped the Internet architecture at large. They operate
(globally) distributed networks of servers to reduce latencies as well as to
increase availability for content and to handle large traffic bursts.
Traditionally, content providers were mostly limited to a single CDN operator.
However, in recent years, more and more content providers employ multiple CDNs
to serve the same content and provide the same services. Thus, switching
between CDNs, which can be beneficial to reduce costs or to select CDNs by
optimal performance in different geographic regions or to overcome CDN-specific
outages, becomes an important task. Services that tackle this task emerged,
also known as CDN broker, Multi-CDN selectors, or Meta-CDNs. Despite their
existence, little is known about Meta-CDN operation in the wild. In this paper,
we thus shed light on this topic by dissecting a major Meta-CDN. Our analysis
provides insights into its infrastructure, its operation in practice, and its
usage by Internet sites. We leverage PlanetLab and Ripe Atlas as distributed
infrastructures to study how a Meta-CDN impacts the web latency
Scalable BGP Prefix Selection for Effective Inter-domain Traffic Engineering
Inter-domain Traffic Engineering for multi-homed networks faces a scalability
challenge, as the size of BGP routing table continue to grow. In this context,
the choice of the best path must be made potentially for each destination
prefix, requiring all available paths to be characterised (e.g., through
measurements) and compared with each other. Fortunately, it is well-known that
a few number of prefixes carry the larger part of the traffic. As a natural
consequence, to engineer large volume of traffic only few prefixes need to be
managed. Yet, traffic characteristics of a given prefix can greatly vary over
time, and little is known on the dynamism of traffic at this aggregation level,
including predicting the set of the most significant prefixes in the near
future. %based on past observations. Sophisticated prediction methods won't
scale in such context. In this paper, we study the relationship between prefix
volume, stability, and predictability, based on recent traffic traces from nine
different networks. Three simple and resource-efficient methods to select the
prefixes associated with the most important foreseeable traffic volume are then
proposed. Such proposed methods allow to select sets of prefixes with both
excellent representativeness (volume coverage) and stability in time, for which
the best routes are identified. The analysis carried out confirm the potential
benefits of a route decision engine
Recommended from our members
Multimedia delivery in the future internet
The term “Networked Media” implies that all kinds of media including text, image, 3D graphics, audio
and video are produced, distributed, shared, managed and consumed on-line through various networks,
like the Internet, Fiber, WiFi, WiMAX, GPRS, 3G and so on, in a convergent manner [1]. This white
paper is the contribution of the Media Delivery Platform (MDP) cluster and aims to cover the Networked
challenges of the Networked Media in the transition to the Future of the Internet.
Internet has evolved and changed the way we work and live. End users of the Internet have been confronted
with a bewildering range of media, services and applications and of technological innovations concerning
media formats, wireless networks, terminal types and capabilities. And there is little evidence that the pace
of this innovation is slowing. Today, over one billion of users access the Internet on regular basis, more
than 100 million users have downloaded at least one (multi)media file and over 47 millions of them do so
regularly, searching in more than 160 Exabytes1 of content. In the near future these numbers are expected
to exponentially rise. It is expected that the Internet content will be increased by at least a factor of 6, rising
to more than 990 Exabytes before 2012, fuelled mainly by the users themselves. Moreover, it is envisaged
that in a near- to mid-term future, the Internet will provide the means to share and distribute (new)
multimedia content and services with superior quality and striking flexibility, in a trusted and personalized
way, improving citizens’ quality of life, working conditions, edutainment and safety.
In this evolving environment, new transport protocols, new multimedia encoding schemes, cross-layer inthe
network adaptation, machine-to-machine communication (including RFIDs), rich 3D content as well as
community networks and the use of peer-to-peer (P2P) overlays are expected to generate new models of
interaction and cooperation, and be able to support enhanced perceived quality-of-experience (PQoE) and
innovative applications “on the move”, like virtual collaboration environments, personalised services/
media, virtual sport groups, on-line gaming, edutainment. In this context, the interaction with content
combined with interactive/multimedia search capabilities across distributed repositories, opportunistic P2P
networks and the dynamic adaptation to the characteristics of diverse mobile terminals are expected to
contribute towards such a vision.
Based on work that has taken place in a number of EC co-funded projects, in Framework Program 6 (FP6)
and Framework Program 7 (FP7), a group of experts and technology visionaries have voluntarily
contributed in this white paper aiming to describe the status, the state-of-the art, the challenges and the way
ahead in the area of Content Aware media delivery platforms
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