Browsing by Author "Yamaguchi, F"

Now showing 1 - 4 of 4

Embargo
Distributed algorithm for router-based management of replica server in next-CDN infrastructure
(IEEE, 2013-10-10) Harahap, E; Wijekoon, J; Tennekoon, R; Yamaguchi, F; Ishida, S; Nishi, H
Extending Content Delivery Network (CDN) infrastructure that has features of router-based network management system (RNMS) is highly appealing and challenging. It allows developing a CDN architecture based upon standard design to ease interoperability, scalability, performance, and flexibility both on network monitoring and management controlled from a router. To better understand the system model, necessity, and the advantages of RNMS, this paper proposed an algorithm that distributed in to a special router called Service-oriented Router (SoR). The function of algorithm is to manage the effective and efficient number of replica server runs in the network. In CDN, minimizing the number of activated replica servers should be considered in order to reduce the operation cost of the system. We propose a semantic approached algorithm that has function to optimize the selection of active replica servers which managed from SoR. The algorithm has capability to find the best location of replica servers and performs load balancing among replica servers. Our simulation result indicates that the proposed algorithm can efficiently activate the replica servers according to user's request with 33.9% effective compared to other algorithm within about one millisecond RTT increase.
Open Access
Modeling of router-based request redirection for content distribution network
(Foundation of Computer Science, 2013-01-01) Harahap, E; Wijekoon, J; Tennekoon, R; Yamaguchi, F; Ishida, S; Nishi, H
The increase of digital data between content’s servers and clients in a network causes congestion problems when downloading big web contents including files, streaming media, etc. The problem becomes pronounced when a narrow bandwidth or unexpected termination of streaming services is appeared. Content Delivery Network (CDN) is introduced to overcome such problems by redirect client’s request to the best server which proximal and least loaded. However, with intensity increase of people accessing a particular content, the performance of CDN is reduced and sometimes congested. We propose an architecture to solve such problems with a new method to redirect client’s request through a special router called Service-oriented Router (SoR). In this paper, several analytical studies and experiments have been conducted and the result show that router-based redirection is more effective than DNS-based redirection that is currently being used. SoR has been introduces as a content-based router and has capability to do deep packet inspection (DPI) into the packet streams and analyze them. We use SoR in our proposed method as a CDN’s core-router to redirect client’s request to the best server. Our experiment conducted with model and numerical analytic supported by optimal redirection probability based on delay between router and server. The experiment result confirmed that the router-based redirection reduced the response time by 23.3% compared to the DNSbased redirection.
Embargo
A router-based management system for prediction of network congestion
(IEEE, 2014-03-14) Harahap, E; Wijekoon, J; Tennekoon, R; Yamaguchi, F; Ishida, S; Nishi, H
Network Management System (NMS) plays an important role in networks to maintain the best performance of a network. It employs variety of tools, applications, and devices in order to support network administrators to monitor and maintain the stability of a network. Fault management is part where the NMS dealing with problems and failures, such as congestion, in the network. Generally, most NMSs use Simple Network Management Protocol (SNMP) to monitor and map network availability, performance, and error rates. In the existing NMS process, an SNMP agent is deployed to get information about the network condition and then send them to the administrator for taking further action on solving the problems. However, deploying such agent to the network may increase the traffic density. On the other hand, packet latency and RTT will increase as well. In this paper, we implemented a prototype of the proposing novel system that no need to deploy such agent to obtain network information. Our system analyze the streaming traffic by implementing a Service-oriented Router (SoR). Our objective is to predict a congestion in the specific link in the network through a router-based data traffic analysis using a Bayesian network model. The purpose of the prediction is to support the network administrator to notify the early warning regarding to the fault in the network as long as possible before it actually happening. By this prediction, the network administrator can immediately taking action to avoid the problems.We provided simulation experiment to demonstrate the performance of the proposed system. Our simulation results show that the proposed system can predict a congestion link caused by a particular problem, before hand it is getting congested.
Embargo
Router-based request redirection management for a next-generation content distribution network
(IEEE, 2013-12-09) Harahap, E; Wijekoon, J; Tennekoon, R; Yamaguchi, F; Nishi, H
The increase in the amount of digital data transferred between contents Servers and Clients in a network causes problems created by congestion when downloading big web files, streaming media, etc. Content Delivery Networks (CDNs) are introduced to overcome such problems by redirecting the Clients request to the nearest Server. However, as the number of people accessing Internet increases rapidly, the performance of CDN is reduced, resulting in network congestion at times. To solve these problems, we propose an architecture in which a new management method is employed to redirect the Clients request using a content-based Router called the Service-oriented Router (SoR). This method is more effective than the currently implemented, traditional DNS-based request redirection (RR). The SoR is a special router that can perform a deep packet inspection of the packet streams. Our experiments were based on analytical modeling as well as test bed experiments, and they confirmed that the response time in the Router-based RR was less than that in the DNS-based RR by 23.3%. In addition, our test bed experiments showed that the RTT in the Router-based RR is less than that in the DNS-based RR by 7.7%.