10,479 research outputs found
Agile-SD: A Linux-based TCP Congestion Control Algorithm for Supporting High-speed and Short-distance Networks
Recently, high-speed and short-distance networks are widely deployed and
their necessity is rapidly increasing everyday. This type of networks is used
in several network applications; such as Local Area Networks (LAN) and Data
Center Networks (DCN). In LANs and DCNs, high-speed and short-distance networks
are commonly deployed to connect between computing and storage elements in
order to provide rapid services. Indeed, the overall performance of such
networks is significantly influenced by the Congestion Control Algorithm (CCA)
which suffers from the problem of bandwidth under-utilization, especially if
the applied buffer regime is very small. In this paper, a novel loss-based CCA
tailored for high-speed and Short-Distance (SD) networks, namely Agile-SD, has
been proposed. The main contribution of the proposed CCA is to implement the
mechanism of agility factor. Further, intensive simulation experiments have
been carried out to evaluate the performance of Agile-SD compared to Compound
and Cubic which are the default CCAs of the most commonly used operating
systems. The results of the simulation experiments show that the proposed CCA
outperforms the compared CCAs in terms of average throughput, loss ratio and
fairness, especially when a small buffer is applied. Moreover, Agile-SD shows
lower sensitivity to the buffer size change and packet error rate variation
which increases its efficiency.Comment: 12 Page
New Cross-Layer Channel Switching Policy for TCP Transmission on 3G UMTS Downlink
In 3G UMTS, two main transport channels have been provided for downlink data
transmission: a common FACH channel and a dedicated DCH channel. The
performance of TCP in UMTS depends much on the channel switching policy used.
In this paper, we propose and analyze three new basic threshold-based channel
switching policies for UMTS that we name as QS (Queue Size), FS (Flow Size) and
QSFS (QS & FS combined) policy. These policies significantly improve over a
modified threshold policy in [1] by about 17% in response time metrics. We
further propose and evaluate a new improved switching policy that we call
FS-DCH (at-least flow-size threshold on DCH) policy. This policy is biased
towards short TCP flows of few packets and is thus a cross-layer policy that
improves the performance of TCP by giving priority to the initial few packets
of a flow on the fast DCH channel. Extensive simulation results confirm this
improvement for the case when number of TCP connections is low
Fixed-Mobile Convergence in the 5G era: From Hybrid Access to Converged Core
The availability of different paths to communicate to a user or device
introduces several benefits, from boosting enduser performance to improving
network utilization. Hybrid access is a first step in enabling convergence of
mobile and fixed networks, however, despite traffic optimization, this approach
is limited as fixed and mobile are still two separate core networks
inter-connected through an aggregation point. On the road to 5G networks, the
design trend is moving towards an aggregated network, where different access
technologies share a common anchor point in the core. This enables further
network optimization in addition to hybrid access, examples are userspecific
policies for aggregation and improved traffic balancing across different
accesses according to user, network, and service context. This paper aims to
discuss the ongoing work around hybrid access and network convergence by
Broadband Forum and 3GPP. We present some testbed results on hybrid access and
analyze some primary performance indicators such as achievable data rates, link
utilization for aggregated traffic and session setup latency. We finally
discuss the future directions for network convergence to enable future
scenarios with enhanced configuration capabilities for fixed and mobile
convergence.Comment: to appear in IEEE Networ
Re-designing Dynamic Content Delivery in the Light of a Virtualized Infrastructure
We explore the opportunities and design options enabled by novel SDN and NFV
technologies, by re-designing a dynamic Content Delivery Network (CDN) service.
Our system, named MOSTO, provides performance levels comparable to that of a
regular CDN, but does not require the deployment of a large distributed
infrastructure. In the process of designing the system, we identify relevant
functions that could be integrated in the future Internet infrastructure. Such
functions greatly simplify the design and effectiveness of services such as
MOSTO. We demonstrate our system using a mixture of simulation, emulation,
testbed experiments and by realizing a proof-of-concept deployment in a
planet-wide commercial cloud system.Comment: Extended version of the paper accepted for publication in JSAC
special issue on Emerging Technologies in Software-Driven Communication -
November 201
A Survey of Green Networking Research
Reduction of unnecessary energy consumption is becoming a major concern in
wired networking, because of the potential economical benefits and of its
expected environmental impact. These issues, usually referred to as "green
networking", relate to embedding energy-awareness in the design, in the devices
and in the protocols of networks. In this work, we first formulate a more
precise definition of the "green" attribute. We furthermore identify a few
paradigms that are the key enablers of energy-aware networking research. We
then overview the current state of the art and provide a taxonomy of the
relevant work, with a special focus on wired networking. At a high level, we
identify four branches of green networking research that stem from different
observations on the root causes of energy waste, namely (i) Adaptive Link Rate,
(ii) Interface proxying, (iii) Energy-aware infrastructures and (iv)
Energy-aware applications. In this work, we do not only explore specific
proposals pertaining to each of the above branches, but also offer a
perspective for research.Comment: Index Terms: Green Networking; Wired Networks; Adaptive Link Rate;
Interface Proxying; Energy-aware Infrastructures; Energy-aware Applications.
18 pages, 6 figures, 2 table
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