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Network overload avoidance by traffic engineering and content caching
Mälardalens högskola, Akademin för innovation, design och teknik.
2012 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

The Internet traffic volume continues to grow at a great rate, now driven by video and TV distribution. For network operators it is important to avoid congestion in the network, and to meet service level agreements with their customers.  This thesis presents work on two methods operators can use to reduce links loads in their networks: traffic engineering and content caching.

This thesis studies access patterns for TV and video and the potential for caching.  The investigation is done both using simulation and by analysis of logs from a large TV-on-Demand system over four months.

The results show that there is a small set of programs that account for a large fraction of the requests and that a comparatively small local cache can be used to significantly reduce the peak link loads during prime time. The investigation also demonstrates how the popularity of programs changes over time and shows that the access pattern in a TV-on-Demand system very much depends on the content type.

For traffic engineering the objective is to avoid congestion in the network and to make better use of available resources by adapting the routing to the current traffic situation. The main challenge for traffic engineering in IP networks is to cope with the dynamics of Internet traffic demands.

This thesis proposes L-balanced routings that route the traffic on the shortest paths possible but make sure that no link is utilised to more than a given level L. L-balanced routing gives efficient routing of traffic and controlled spare capacity to handle unpredictable changes in traffic.  We present an L-balanced routing algorithm and a heuristic search method for finding L-balanced weight settings for the legacy routing protocols OSPF and IS-IS. We show that the search and the resulting weight settings work well in real network scenarios.

Ort, förlag, år, upplaga, sidor
Västerås: Mälardalen University , 2012.
Serie
Mälardalen University Press Dissertations, ISSN 1651-4238 ; 133
Nationell ämneskategori
Datorteknik
Forskningsämne
datavetenskap
Identifikatorer
URN: urn:nbn:se:mdh:diva-16107ISBN: 978-91-7585-087-1 OAI: oai:DiVA.org:mdh-16107DiVA: diva2:565409
Disputation
2012-12-19, Kappa, Mälardalens högskola, Västerås, 13:15 (Engelska)
Opponent
Handledare
Tillgänglig från: 2012-11-07 Skapad: 2012-11-06 Senast uppdaterad: 2012-11-19Bibliografiskt granskad
Delarbeten
1. A Multi Path Routing Algorithm for IP Networks Based on Flow Optimisation
Öppna denna publikation i ny flik eller fönster >>A Multi Path Routing Algorithm for IP Networks Based on Flow Optimisation
Visa övriga...
2002 (Engelska)Ingår i: Proceedings of the Third International Workshop on Quality of Future Internet Services / [ed] Burkhard Stiller, Springer Berlin/Heidelberg, 2002, 135-144 s.Konferensbidrag, Publicerat paper (Refereegranskat)
Ort, förlag, år, upplaga, sidor
Springer Berlin/Heidelberg, 2002
Serie
Lecture Notes in Computer Science, ISSN 0302-9743 ; 2511
Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:mdh:diva-1305 (URN)10.1007/3-540-45859-X_13 (DOI)3-540-44356-8 (ISBN)
Konferens
International Workshop on Quality of Future Internet Services, QofIS 2002 and Second International Workshop on Internet Charging and QoS Technologies, ICQT 2002 Zurich, Switzerland, October 16–18,
Tillgänglig från: 2008-10-14 Skapad: 2008-10-14 Senast uppdaterad: 2012-11-08Bibliografiskt granskad
2. Robust Traffic Engineering using L-balanced Weight-Settings in OSPF/IS-IS
Öppna denna publikation i ny flik eller fönster >>Robust Traffic Engineering using L-balanced Weight-Settings in OSPF/IS-IS
2009 (Engelska)Ingår i: Proceedings of the 2009 6th International Conference on Broadband Communications, Networks and Systems, BROADNETS 2009, 2009Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

Internet traffic volumes continue to grow at a great rate, now pushed by video and TV distribution in the networks. This brings up the need for traffic engineering mechanisms to better control the traffic. The objective of traffic engineering is to avoid congestion in the network and make good use of available resources by controlling and optimising the routing function. The challenge for traffic engineering in IP networks is to cope with the dynamics of Internet traffic demands. Today, the main alternative for intra-domain traffic engineering in IP networks is to use different methods for setting the weights in the routing protocols OSPF and IS-IS. In this paper we revisit the weight setting approach to traffic engineering but with focus on robustness. We propose I-balanced weight settings that route the traffic on the shortest paths possible but make sure that no link is utilised to more than a given level I. This gives efficient routing of traffic and controlled spare capacity to handle unpredictable changes in traffic. We present a heuristic search method for finding I-balanced weight settings and show that it works well in real network scenarios

Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:mdh:diva-9104 (URN)10.4108/ICST.BROADNETS2009.7184 (DOI)2-s2.0-74549167229 (Scopus ID)978-963979949-3 (ISBN)
Konferens
2009 6th International Conference on Broadband Communications, Networks and Systems, BROADNETS 2009; Madrid; 14-16 September 2009
Tillgänglig från: 2010-03-03 Skapad: 2010-03-03 Senast uppdaterad: 2013-12-03Bibliografiskt granskad
3. Simulation of IPTV caching strategies
Öppna denna publikation i ny flik eller fönster >>Simulation of IPTV caching strategies
2010 (Engelska)Ingår i: Proceedings of the 2010 International Symposium on Performance Evaluation of Computer and Telecommunication Systems, 2010, 187-193 s.Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

IPTV, where television is distributed over the Internet Protocol in a single operator network, has become popular and widespread. Many telecom and broadband companies have become TV providers and distribute TV channels using multicast over their backbone networks. IPTV also means an evolution to time-shifted television where viewers now often can choose to watch the programs at any time. However, distributing individual TV streams to each viewer requires a lot of bandwidth and is a big challenge for TV operators. In this paper we present an empirical IPTV workload model, simulate IPTV distribution with time-shift, and show that local caching can limit the bandwidth requirements significantly.

Nationell ämneskategori
Datorteknik
Identifikatorer
urn:nbn:se:mdh:diva-16104 (URN)2-s2.0-78649246964 (Scopus ID)
Konferens
International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS’10); Ottawa,11-14 July 2010
Tillgänglig från: 2012-11-06 Skapad: 2012-11-06 Senast uppdaterad: 2013-12-03Bibliografiskt granskad
4. Caching for IPTV distribution with time-shift
Öppna denna publikation i ny flik eller fönster >>Caching for IPTV distribution with time-shift
2013 (Engelska)Ingår i: 2013 International Conference on Computing, Networking and Communications, ICNC 2013, IEEE , 2013, 916-921 s.Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

Today video and TV distribution dominate Internet traffic and the increasing demand for high-bandwidth multimedia services puts pressure on Internet service providers. In this paper we simulate TV distribution with time-shift and investigate the effect of introducing a local cache close to the viewers. We study what impact TV program popularity, program set size, cache replacement policy and other factors have on the caching efficiency. The simulation results show that introducing a local cache close to the viewers significantly reduces the network load from TV-on-Demand services. By caching 4% of the program volume we can decrease the peak load during prime time by almost 50%. We also show that the TV program type and how program popularity changes over time can have a big influence on cache hit ratios and the resulting link loads

Ort, förlag, år, upplaga, sidor
IEEE, 2013
Nationell ämneskategori
Datorteknik
Identifikatorer
urn:nbn:se:mdh:diva-16105 (URN)10.1109/ICCNC.2013.6504212 (DOI)2-s2.0-84877597829 (Scopus ID)978-146735288-8 (ISBN)
Konferens
2013 International Conference on Computing, Networking and Communications, ICNC 2013; San Diego, CA; United States; 28 January 2013 through 31 January 2013
Tillgänglig från: 2012-11-06 Skapad: 2012-11-06 Senast uppdaterad: 2016-03-10Bibliografiskt granskad
5. Program popularity and viewer behaviour in a large TV-on-Demand system
Öppna denna publikation i ny flik eller fönster >>Program popularity and viewer behaviour in a large TV-on-Demand system
2012 (Engelska)Ingår i: IMC '12 Proceedings of the 2012 ACM conference on Internet measurement conference, New York: ACM , 2012, 199-210 s.Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

Today increasingly large volumes of TV and video are distributed over IP-networks and over the Internet. It is therefore essential for traffic and cache management to understand TV program popularity and access patterns in real networks.

In this paper we study access patterns in a large TV-on-Demand system over four months. We study user behaviour and program popularity and its impact on caching. The demand varies a lot in daily and weekly cycles. There are large peaks in demand, especially on Friday and Saturday evenings, that need to be handled.

We see that the cacheability, the share of requests that are not first-time requests, is very high. Furthermore, there is a small set of programs that account for a large fraction of the requests. We also find that the share of requests for the top most popular programs grows during prime time, and the change rate among them decreases. This is important for caching. The cache hit ratio increases during prime time when the demand is the highest, and aching makes the biggest difference when it matters most.

We also study the popularity (in terms of number of requests and rank) of individual programs and how that changes over time. Also, we see that the type of programs offered determines what the access pattern will look like.

Ort, förlag, år, upplaga, sidor
New York: ACM, 2012
Nationell ämneskategori
Datorteknik
Identifikatorer
urn:nbn:se:mdh:diva-16106 (URN)10.1145/2398776.2398798 (DOI)978-1-4503-1705-4 (ISBN)
Konferens
Internet Measurement Conference 2012 (IMC’12), November 14-16, 2012 Boston Massachusetts USA
Tillgänglig från: 2012-11-06 Skapad: 2012-11-06 Senast uppdaterad: 2012-12-05Bibliografiskt granskad

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