George Parisis

George Parisis

orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 July 2012 in IEEE Communications Magazine
Verified
Journal Article
Closed access
DTDirk Trossen
Dirk Trossen
GPGeorge Parisis
George Parisis
Information-centric networking has been attracting increasing attention within the networking community. Technological solutions as well as entire architectures have been proposed with subtle but seemingly important differences. In this article, we define a set of design tenets for an information-centric architecture together with a demonstration of its feasibility. For the latter, we present an early prototype of an artifact that is directly based on our design framework. This prototype is available under open source, deployed in a European-wide testbed, and can be used for Planetlab-scale experiments. Early indications of its performance show promising results for our future work.

1 April 2016
Verified
Conference Paper
Closed access
MKMorteza Kheirkhah
Morteza Kheirkhah
IWIan Wakeman
Ian Wakeman
GPGeorge Parisis
George Parisis
Modern data centres provide large aggregate network capacity and multiple paths among servers. Traffic is very diverse; most of the data is produced by long, bandwidth hungry flows but the large majority of flows, which commonly come with strict deadlines regarding their completion time, are short. It has been shown that TCP is not efficient for any of these types of traffic in modern data centres. More recent protocols such MultiPath TCP (MPTCP) are very efficient for long flows, but are ill-suited for short flows. In this paper, we present Maximum MultiPath TCP (MMPTCP), a novel transport protocol which, compared to TCP and MPTCP, reduces short flows' completion times, while providing excellent goodput to long flows. To do so, MMPTCP runs in two phases; initially, it randomly scatters packets in the network under a single congestion window exploiting all available paths. This is beneficial to latency-sensitive flows. After a specific amount of data is sent, MMPTCP switches to a regular MultiPath TCP mode. MMPTCP is incrementally deployable in existing data centres as it does not require any modifications outside the transport layer and behaves well when competing with legacy TCP and MPTCP flows. Our extensive experimental evaluation in simulated FatTree topologies shows that all design objectives for MMPTCP are met.

1 June 2008 in Electronic Commerce Research and Applications
Verified
Journal Article
Closed access
AKApostolos Kousaridas
Apostolos Kousaridas
GPGeorge Parisis
George Parisis
TATheodore Apostolopoulos
Theodore Apostolopoulos

1 October 2012
Verified
Conference Paper
Closed access
DSDimitris Syrivelis
Dimitris Syrivelis
GPGeorge Parisis
George Parisis
DTDirk Trossen
Dirk Trossen
PFParis Flegkas
Paris Flegkas
VSVasilis Sourlas
Vasilis Sourlas
LTLeandros Tassiulas
Leandros Tassiulas
The areas of Software-Defined Networking (SDN) and Information-Centric Networking (ICN) have gained increasing attention in the wider research community, while gaining credibility through corporate interest and investment. With the promise of SDN to simplify the deployment of alternative network architectures, the question arises how SDN and ICN could concretely be combined, deployed and tested. In this paper, we address this very question within a particular architectural context for ICN. We outline a possible realization in a novel design for ICN solutions and point to possible test bed deployments for future testing.

23 February 2021 in IEEE/ACM Transactions on Networking
Verified
Journal Article
Closed access
MAMohammed Alasmar
Mohammed Alasmar
RCRichard Clegg
Richard Clegg
NZNickolay Zakhleniuk
Nickolay Zakhleniuk
GPGeorge Parisis
George Parisis
Getting good statistical models of traffic on network links is a well-known, often-studied problem. A lot of attention has been given to correlation patterns and flow duration. The distribution of the amount of traffic per unit time is an equally important but less studied problem. We study a large number of traffic traces from many different networks including academic, commercial and residential networks using state-of-the-art statistical techniques. We show that traffic obeys the log-normal distribution which is a better fit than the Gaussian distribution commonly claimed in the literature. We also investigate an alternative heavy-tailed distribution (the Weibull) and show that its performance is better than Gaussian but worse than log-normal. We examine anomalous traces which exhibit a poor fit for all distributions tried and show that this is often due to traffic outages or links that hit maximum capacity. We demonstrate that the data we look at is stationary if we consider samples of 15-minute long or even 1-hour long. This gives confidence that we can use the distributions for estimation and modelling purposes. We demonstrate the utility of our findings in two contexts: predicting that the proportion of time traffic will exceed a given level (for service level agreement or link capacity estimation) and predicting 95th percentile pricing. We also show that the log-normal distribution is a better predictor than Gaussian or Weibull distributions in both contexts.

1 April 2019
Verified
Conference Paper
Closed access
MAMohammed Alasmar
Mohammed Alasmar
GPGeorge Parisis
George Parisis
RCRichard Clegg
Richard Clegg
NZNickolay Zakhleniu
Nickolay Zakhleniu
Getting good statistical models of traffic on network links is a well-known, often-studied problem. A lot of attention has been given to correlation patterns and flow duration. The distribution of the amount of traffic per unit time is an equally important but less studied problem. We study a large number of traffic traces from many different networks including academic, commercial and residential networks using state-of-the-art statistical techniques. We show that the log-normal distribution is a better fit than the Gaussian distribution commonly claimed in the literature. We also investigate a second heavy-tailed distribution (the Weibull) and show that its performance is better than Gaussian but worse than log-normal. We examine anomalous traces which are a poor fit for all distributions tried and show that this is often due to traffic outages or links that hit maximum capacity.We demonstrate the utility of the log-normal distribution in two contexts: predicting the proportion of time traffic will exceed a given level (for service level agreement or link capacity estimation) and predicting 95th percentile pricing. We also show the log-normal distribution is a better predictor than Gaussian or Weibull distributions.