3,138 research outputs found
TCP Congestion Control Identification
Transmission Control Protocol (TCP) carries most of the traffic on the
Internet these days. There are several implementations of TCP, and the most
important difference among them is their mechanism for controlling congestion.
One of the methods for determining type of a TCP is active probing. Active
probing considers a TCP implementation as a black box, sends different streams
of data to the appropriate host. According to the response received from the
host, it figures out the type of TCP version implemented.
TCP Behavior Inference Tool (TBIT) is an implemented tool that uses active
probing to check the running TCP on web servers. It can check several aspects
of the running TCP including initial value of congestion window, congestion
control algorithm, conformant congestion control, response to selective
acknowledgment, response to Explicit Congestion Notification (ECN) and time
wait duration. In this paper we focus on congestion control algorithm aspect of
it, explain the mechanism used by TBIT and present the results
A First Look at QUIC in the Wild
For the first time since the establishment of TCP and UDP, the Internet
transport layer is subject to a major change by the introduction of QUIC.
Initiated by Google in 2012, QUIC provides a reliable, connection-oriented
low-latency and fully encrypted transport. In this paper, we provide the first
broad assessment of QUIC usage in the wild. We monitor the entire IPv4 address
space since August 2016 and about 46% of the DNS namespace to detected
QUIC-capable infrastructures. Our scans show that the number of QUIC-capable
IPs has more than tripled since then to over 617.59 K. We find around 161K
domains hosted on QUIC-enabled infrastructure, but only 15K of them present
valid certificates over QUIC. Second, we analyze one year of traffic traces
provided by MAWI, one day of a major European tier-1 ISP and from a large IXP
to understand the dominance of QUIC in the Internet traffic mix. We find QUIC
to account for 2.6% to 9.1% of the current Internet traffic, depending on the
vantage point. This share is dominated by Google pushing up to 42.1% of its
traffic via QUIC
Don't Repeat Yourself: Seamless Execution and Analysis of Extensive Network Experiments
This paper presents MACI, the first bespoke framework for the management, the
scalable execution, and the interactive analysis of a large number of network
experiments. Driven by the desire to avoid repetitive implementation of just a
few scripts for the execution and analysis of experiments, MACI emerged as a
generic framework for network experiments that significantly increases
efficiency and ensures reproducibility. To this end, MACI incorporates and
integrates established simulators and analysis tools to foster rapid but
systematic network experiments.
We found MACI indispensable in all phases of the research and development
process of various communication systems, such as i) an extensive DASH video
streaming study, ii) the systematic development and improvement of Multipath
TCP schedulers, and iii) research on a distributed topology graph pattern
matching algorithm. With this work, we make MACI publicly available to the
research community to advance efficient and reproducible network experiments
A Comparative Case Study of HTTP Adaptive Streaming Algorithms in Mobile Networks
HTTP Adaptive Streaming (HAS) techniques are now the dominant solution for
video delivery in mobile networks. Over the past few years, several HAS
algorithms have been introduced in order to improve user quality-of-experience
(QoE) by bit-rate adaptation. Their difference is mainly the required input
information, ranging from network characteristics to application-layer
parameters such as the playback buffer. Interestingly, despite the recent
outburst in scientific papers on the topic, a comprehensive comparative study
of the main algorithm classes is still missing. In this paper we provide such
comparison by evaluating the performance of the state-of-the-art HAS algorithms
per class, based on data from field measurements. We provide a systematic study
of the main QoE factors and the impact of the target buffer level. We conclude
that this target buffer level is a critical classifier for the studied HAS
algorithms. While buffer-based algorithms show superior QoE in most of the
cases, their performance may differ at the low target buffer levels of live
streaming services. Overall, we believe that our findings provide valuable
insight for the design and choice of HAS algorithms according to networks
conditions and service requirements.Comment: 6 page
User-space Multipath UDP in Mosh
In many network topologies, hosts have multiple IP addresses, and may choose
among multiple network paths by selecting the source and destination addresses
of the packets that they send. This can happen with multihomed hosts (hosts
connected to multiple networks), or in multihomed networks using
source-specific routing. A number of efforts have been made to dynamically
choose between multiple addresses in order to improve the reliability or the
performance of network applications, at the network layer, as in Shim6, or at
the transport layer, as in MPTCP. In this paper, we describe our experience of
implementing dynamic address selection at the application layer within the
Mobile Shell. While our work is specific to Mosh, we hope that it is generic
enough to serve as a basis for designing UDP-based multipath applications or
even more general APIs
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