18,274 research outputs found
Comparative Study Of Congestion Control Techniques In High Speed Networks
Congestion in network occurs due to exceed in aggregate demand as compared to
the accessible capacity of the resources. Network congestion will increase as
network speed increases and new effective congestion control methods are
needed, especially to handle bursty traffic of todays very high speed networks.
Since late 90s numerous schemes i.e. [1]...[10] etc. have been proposed. This
paper concentrates on comparative study of the different congestion control
schemes based on some key performance metrics. An effort has been made to judge
the performance of Maximum Entropy (ME) based solution for a steady state
GE/GE/1/N censored queues with partial buffer sharing scheme against these key
performance metrics.Comment: 10 pages IEEE format, International Journal of Computer Science and
Information Security, IJCSIS November 2009, ISSN 1947 5500,
http://sites.google.com/site/ijcsis
ATP: a Datacenter Approximate Transmission Protocol
Many datacenter applications such as machine learning and streaming systems
do not need the complete set of data to perform their computation. Current
approximate applications in datacenters run on a reliable network layer like
TCP. To improve performance, they either let sender select a subset of data and
transmit them to the receiver or transmit all the data and let receiver drop
some of them. These approaches are network oblivious and unnecessarily transmit
more data, affecting both application runtime and network bandwidth usage. On
the other hand, running approximate application on a lossy network with UDP
cannot guarantee the accuracy of application computation. We propose to run
approximate applications on a lossy network and to allow packet loss in a
controlled manner. Specifically, we designed a new network protocol called
Approximate Transmission Protocol, or ATP, for datacenter approximate
applications. ATP opportunistically exploits available network bandwidth as
much as possible, while performing a loss-based rate control algorithm to avoid
bandwidth waste and re-transmission. It also ensures bandwidth fair sharing
across flows and improves accurate applications' performance by leaving more
switch buffer space to accurate flows. We evaluated ATP with both simulation
and real implementation using two macro-benchmarks and two real applications,
Apache Kafka and Flink. Our evaluation results show that ATP reduces
application runtime by 13.9% to 74.6% compared to a TCP-based solution that
drops packets at sender, and it improves accuracy by up to 94.0% compared to
UDP
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
Optimizing Service Differentiation Scheme with Sized-based Queue Management in DiffServ Networks
In this paper we introduced Modified Sized-based Queue Management as a
dropping scheme that aims to fairly prioritize and allocate more service to
VoIP traffic over bulk data like FTP as the former one usually has small packet
size with less impact to the network congestion. In the same time, we want to
guarantee that this prioritization is fair enough for both traffic types. On
the other hand we study the total link delay over the congestive link with the
attempt to alleviate this congestion as much as possible at the by function of
early congestion notification. Our M-SQM scheme has been evaluated with NS2
experiments to measure the packets received from both and total link-delay for
different traffic. The performance evaluation results of M-SQM have been
validated and graphically compared with the performance of other three legacy
AQMs (RED, RIO, and PI). It is depicted that our M-SQM outperformed these AQMs
in providing QoS level of service differentiation.Comment: 10 pages, 9 figures, 1 table, Submitted to Journal of
Telecommunication
Less-than-Best-Effort capacity sharing over high BDP networks with LEDBAT
There has been a renewed interest at the Internet Engineering Task Force (IETF) in using Less-than-Best Effort (LBE) methods for background applications. IETF recently published a RFC for Low Extra Delay Background Transport (LEDBAT), a congestion control algorithm for LBE transmissions. This paper provides an analysis of LEDBAT performance over congested large bandwidth X delay product (LBDP) networks, and assesses the validity of having a fixed target queuing time. In particular, we lead a study of the impact of this target queuing delay when LEDBAT is used over 4G satellite networks. The rationale is to explore the possibility to grab the unused 4G satellite links' capacity to carry non-commercial traffic. We show that this is achievable with LEDBAT. However, depending on the fluctuation of the load, performance improvements could be obtained by properly setting the target value. We generalize this evaluation over different congested LBDP networks and confirm that the target value might need to be adjusted to networks' and traffic's characteristics. Further work will study whether and how this parameter should be dynamically adapted, and LEDBAT's congestion control improved
CloudJet4BigData: Streamlining Big Data via an Accelerated Socket Interface
Big data needs to feed users with fresh processing results and cloud platforms can be used to speed up big data applications. This paper describes a new data communication protocol (CloudJet) for long distance and large volume big data accessing operations to alleviate the large latencies encountered in sharing big data resources in the clouds. It encapsulates a dynamic multi-stream/multi-path engine at the socket level, which conforms to Portable Operating System Interface (POSIX) and thereby can accelerate any POSIX-compatible applications across IP based networks. It was demonstrated that CloudJet accelerates typical big data applications such as very large database (VLDB), data mining, media streaming and office applications by up to tenfold in real-world tests
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