With the rapidly growing market for smartphones and user’s confidence for immediate
access to high-quality multimedia content, the delivery of video over wireless networks has
become a big challenge. It makes it challenging to accommodate end-users with flawless
quality of service. The growth of the smartphone market goes hand in hand with the
development of the Internet, in which current transport protocols are being re-evaluated to
deal with traffic growth. QUIC and WebRTC are new and evolving standards. The latter
is a unique and evolving standard explicitly developed to meet this demand and enable
a high-quality experience for mobile users of real-time communication services. QUIC
has been designed to reduce Web latency, integrate security features, and allow a highquality
experience for mobile users. Thus, the need to evaluate the performance of these
rising protocols in a non-systematic environment is essential to understand the behavior
of the network and provide the end user with a better multimedia delivery service. Since
most of the work in the research community is conducted in a controlled environment, we
leverage the MONROE platform to investigate the performance of QUIC and WebRTC
in real cellular networks using static and mobile nodes. During this Thesis, we conduct
measurements ofWebRTC and QUIC while making their data-sets public to the interested
experimenter. Building such data-sets is very welcomed with the research community,
opening doors to applying data science to network data-sets. The development part of the
experiments involves building Docker containers that act as QUIC and WebRTC clients.
These containers are publicly available to be used candidly or within the MONROE
platform. These key contributions span from Chapter 4 to Chapter 5 presented in Part
II of the Thesis.
We exploit data collection from MONROE to apply data science over network
data-sets, which will help identify networking problems shifting the Thesis focus from
performance evaluation to a data science problem.
Indeed, the second part of the Thesis focuses on interpretable data science. Identifying
network problems leveraging Machine Learning (ML) has gained much visibility in the
past few years, resulting in dramatically improved cellular network services. However,
critical tasks like troubleshooting cellular networks are still performed manually by experts
who monitor the network around the clock. In this context, this Thesis contributes by proposing the use of simple interpretable
ML algorithms, moving away from the current trend of high-accuracy ML algorithms
(e.g., deep learning) that do not allow interpretation (and hence understanding) of their
outcome. We prefer having lower accuracy since we consider it interesting (anomalous)
the scenarios misclassified by the ML algorithms, and we do not want to miss them by
overfitting. To this aim, we present CIAN (from Causality Inference of Anomalies in
Networks), a practical and interpretable ML methodology, which we implement in the
form of a software tool named TTrees (from Troubleshooting Trees) and compare it to
a supervised counterpart, named STress (from Supervised Trees). Both methodologies
require small volumes of data and are quick at training. Our experiments using real
data from operational commercial mobile networks e.g., sampled with MONROE probes,
show that STrees and CIAN can automatically identify and accurately classify network
anomalies—e.g., cases for which a low network performance is not justified by operational
conditions—training with just a few hundreds of data samples, hence enabling precise
troubleshooting actions. Most importantly, our experiments show that a fully automated
unsupervised approach is viable and efficient. In Part III of the Thesis which includes
Chapter 6 and 7.
In conclusion, in this Thesis, we go through a data-driven networking roller coaster,
from performance evaluating upcoming network protocols in real mobile networks to
building methodologies that help identify and classify the root cause of networking
problems, emphasizing the fact that these methodologies are easy to implement and can
be deployed in production environments.This work has been supported by IMDEA Networks InstitutePrograma de Doctorado en Multimedia y Comunicaciones por la Universidad Carlos III de Madrid y la Universidad Rey Juan CarlosPresidente: Matteo Sereno.- Secretario: Antonio de la Oliva Delgado.- Vocal: Raquel Barco Moren
