598 research outputs found
IETF standardization in the field of the Internet of Things (IoT): a survey
Smart embedded objects will become an important part of what is called the Internet of Things. However, the integration of embedded devices into the Internet introduces several challenges, since many of the existing Internet technologies and protocols were not designed for this class of devices. In the past few years, there have been many efforts to enable the extension of Internet technologies to constrained devices. Initially, this resulted in proprietary protocols and architectures. Later, the integration of constrained devices into the Internet was embraced by IETF, moving towards standardized IP-based protocols. In this paper, we will briefly review the history of integrating constrained devices into the Internet, followed by an extensive overview of IETF standardization work in the 6LoWPAN, ROLL and CoRE working groups. This is complemented with a broad overview of related research results that illustrate how this work can be extended or used to tackle other problems and with a discussion on open issues and challenges. As such the aim of this paper is twofold: apart from giving readers solid insights in IETF standardization work on the Internet of Things, it also aims to encourage readers to further explore the world of Internet-connected objects, pointing to future research opportunities
Available Bandwidth Estimation Tools Metrics, Approaches and Performance
The estimation of the available bandwidth (av bw) between two end nodes through the Internet, is an area that has motivated researchers around the world in the last twenty years, to have faster and more accurate tools; Due to the utility it has in various network applications; Such as routing management, intrusion detection systems and the performance of transport protocols. Different tools use different estimation techniques but generally only analyze the three most used metrics as av bw, relative error and estimation time. This work expands the information regarding the evaluation literature of the current Available Bandwidth Estimation Tools (ABET’s), where they analyze the estimation techniques, metrics, different generation tools of cross-traf?c and evaluation testbed; Concentrating on the techniques and estimation methodologies used, as well as the challenges faced by open-source tools in high-performance networks of 10Gbps or higher
Available Bandwidth Estimation Tools Metrics, Approaches and Performance
The estimation of the available bandwidth (av_bw)
between two end nodes through the Internet, is an area that has
motivated researchers around the world in the last twenty years, to
have faster and more accurate tools; Due to the utility it has in
various network applications; Such as routing management,
intrusion detection systems and the performance of transport
protocols. Different tools use different estimation techniques but
generally only analyze the three most used metrics as av_bw,
relative error and estimation time. This work expands the
information regarding the evaluation literature of the current
Available Bandwidth Estimation Tools (ABET's), where they
analyze the estimation techniques, metrics, different generation
tools of cross-traffic and evaluation testbed; Concentrating on the
techniques and estimation methodologies used, as well as the
challenges faced by open-source tools in high-performance
networks of 10 Gbps or higher
SDN based testbeds for evaluating and promoting multipath TCP
Multipath TCP is an experimental transport proto-
col with remarkable recent past and non-negligible future poten-
tial. It has been standardized recently, however the evaluation
studies focus only on a limited set of isolated use-cases and
a comprehensive analysis or a feasible path of Internet-wide
adoption is still missing. This is mostly because in the current
networking practice it is unusual to configure multiple paths
between the endpoints of a connection. Therefore, conducting and
precisely controlling multipath experiments over the real “inter-
net” is a challenging task for some experimenters and impossible
for others. In this paper, we invoke SDN technology to make
this control possible and exploit large-scale internet testbeds to
conduct end-to-end MPTCP experiments. More specifically, we
establish a special purpose control and measurement framework
on top of two distinct internet testbeds. First, using the OpenFlow
support of GÉANT, we build a testbed enabling measurements
with real traffic. Second, we design and establish a publicly
available large-scale multipath capable measurement framework
on top of PlanetLab Europe and show the challenges of such
a system. Furthermore, we present measurements results with
MPTCP in both testbeds to get insight into its behavior in such
not well explored environment
IETF standardization in the field of the internet of things (IoT): a survey
Smart embedded objects will become an important part of what is called the Internet of Things. However, the integration of embedded devices into the Internet introduces several challenges, since many of the existing Internet technologies and protocols were not designed for this class of devices. In the past few years, there have been many efforts to enable the extension of Internet technologies to constrained devices. Initially, this resulted in proprietary protocols and architectures. Later, the integration of constrained devices into the Internet was embraced by IETF, moving towards standardized IP-based protocols. In this paper, we will briefly review the history of integrating constrained devices into the Internet, followed by an extensive overview of IETF standardization work in the 6LoWPAN, ROLL and CoRE working groups. This is complemented with a broad overview of related research results that illustrate how this work can be extended or used to tackle other problems and with a discussion on open issues and challenges. As such the aim of this paper is twofold: apart from giving readers solid insights in IETF standardization work on the Internet of Things, it also aims to encourage readers to further explore the world of Internet-connected objects, pointing to future research opportunities.The research leading to these results has received funding from the European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement no 258885 (SPITFIRE project), from the iMinds ICON projects GreenWeCan and O’CareCloudS, a FWO postdoc grant for Eli De Poorter and a VLIR PhD scholarship to Isam Ishaq
Evaluation and optimisation of Less-than-Best-Effort TCP congestion control mechanisms
Increasing use of online software installation, updates, and backup services, as well as the popularity of user-generated content, has increased the demand for band-width in recent years. Traffic generated by these applications — when receiving a ‘fair-share’ of the available bandwidth — can impact the responsiveness of delay-sensitive applications. Less-than-Best-Effort TCP congestion control mechanisms aim to allow lower-priority applications to utilise excess bandwidth with minimum impact to regular TCP carrying delay-sensitive traffic. However, no previous study has evaluated the performance of a large number of this class of congestion con-trol mechanisms. This thesis quantifies the performance of existing Less-than-Best-Effort TCP congestion control mechanisms, and proposes a new mechanism to im-prove the performance of these mechanisms with high path delay.
This study first evaluated the performance of seven Less-than-Best-Effort conges-tion control mechanisms in realistic scenarios under a range of network conditions in a Linux testbed incorporating wired Ethernet and 802.11n wireless links. The seven mechanisms evaluated were: Apple LEDBAT, CAIA Delay-Gradient (CDG), RFC6817 LEDBAT, Low Priority, Nice, Westwood-LP, and Vegas. Of these mecha-nisms, only four had existing implementations for modern operating systems. The remaining three mechanisms — Apple LEDBAT, Nice, and Westwood-LP — were implemented based on published descriptions and available code fragments to fa-cilitate this evaluation.
The results of the evaluation suggest that Less-than-Best-Effort congestion control mechanisms can be divided into two categories: regular TCP-like mechanisms, and low-impact mechanisms. Of the low-impact mechanisms, two mechanisms were identified as having desirable performance characteristics: Nice and CDG. Nice pro-vides background throughput comparable to regular TCP while maintaining low queuing delay in low path delay settings. CDG has the least impact on regular TCP traffic, at the expense of reduced throughput. In high path-delay settings, these reductions to throughput experienced by CDG are exacerbated, while Nice has a greater impact on regular TCP traffic.
To address the very low throughput of existing Less-than-Best-Effort congestion control mechanisms in high path-delay settings, a new Less-than-Best-Effort TCP congestion control algorithm was developed and implemented: Yield TCP. Yield utilises elements of a Proportional-Integral controller to better interpret and re-spond to changes in queuing delay to achieve this goal while also reducing the impact on regular TCP traffic over TCP-like mechanisms. Source code for the im-plementation of Yield developed for this research has also been made available.
The results of evaluating Yield indicate that it successfully addresses the low through-put of low-impact Less-than-Best-Effort mechanisms in high delay settings, while also reducing the impact on foreground traffic compared to regular TCP-like con-gestion control mechanisms. Yield also performs similarly to Nice in low delay settings, while also achieving greater intra-protocol fairness than Nice across all settings. These results indicate that Yield addresses the weaknesses of Nice and CDG, and is a promising alternative to existing Less-than-Best-Effort congestion control algorithms
Overhead in available bandwidth estimation tools: Evaluation and analysis
Current Available Bandwidth Estimation Tools
(ABET) insert into the network probing packets to perform a single
estimation. The utilization of these packets makes ABET intrusive
and prone to errors since they consume part of the available
bandwidth they are measuring. This paper presents a comparative of
Overhead Estimation Tools (OET) analysis of representative
ABET: Abing, Diettopp, Pathload, PathChirp, Traceband, IGI,
PTR, Assolo, and Wbest. By using Internet traffic, the study shows
that the insertion of probing packets is a factor that affects two
metrics associated to the estimation. First, it is shown that the
accuracy is affected proportionally to the amount of probing traffic.
Secondly, the Estimation Time (ET) is increased in high congested
end-to-end links when auto-induced congestion tools are use
Overhead in Available Bandwidth Estimation Tools: Evaluation and Analysis
The current Available Bandwidth Estimation Tools (ABET's) to perform an estimation, using probes packets are inserted into the network. The utilization These packages, makes ABET's are intrusive and consumes part of which is measuring bandwidth to noise known as "Overhead Estimation Tools" (OET); it’s can produce negative effects on measurements performed by the ABET. This paper presents a complete and comparative analysis of behavior of Available Bandwidth (av_bw), of the ABET's most representative, as well as: Abing, Diettopp, Pathload, PathChirp, Traceband, IGI, PTR, Assolo and Wbest. The study with real Internet traffic, shows the percentage of test that is a factor packets affecting two main aspects of the estimation. The first, the accuracy, and increased indicating that EOT is directly proportional to the percentage of RE, reaching up to 70% in the tool evaluated with most of 30% of Cross-Traffic (CT). And second, the techniques used to send probes packets highly influences the Estimation Time (ET), where some tools that use slops spend up to 240s to converge when there is 60% CT in the network, ensuring that the estimate this technique av_bw highly congested channel, OET as much is used, resulting in inaccuracies in measurement
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