The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform

Min Young Chung - One of the best experts on this subject based on the ideXlab platform.

  • Inter-Domain QoS Routing Scheme using Link State Information
    2008 10th International Conference on Advanced Communication Technology, 2008
    Co-Authors: Hae-won Jung, Min Young Chung
    Abstract:

    In the Internet, in order to guarantee Quality of Service (QoS), all routers have to manage their Link State Databases (LSDBs) and determine a routing path that satisfies service requirements based on the LSDB. In addition, routing protocols have to provide QoS not only in the intra- domain but also in the inter-domain to enable the end to end QoS guarantee. In the intra-domain routing, it is possible that a router manages its LSDB because the Link State information is small in a domain. On the other hand, in inter- domain routing, since the amount of the Link State information is very large, it is unrealistic to manage the whole Link State information. The Border Gateway Protocol (BGP) is the most prominent inter-domain routing protocol in the current internet. However, it is difficult to guarantee the inter-domain QoS using BGP because the BGP is a path- vector based protocol. In this paper, we propose the inter- domain QoS routing schemes that can manage the LSDBs effectively and minimize a waste of the network system resources by Link State Update (LSU) massages. We evaluate the performance of the proposed schemes by simulations. From the results, the proposed schemes can reduce the blocking probability and amount of the Link State Update with a few Link State information.

  • a Link State Update algorithm based on a statistical threshold for guarantee of bandwidth
    Journal of KIISE:Information Networking, 2008
    Co-Authors: Min Young Chung, Hyunseung Choo
    Abstract:

    In order to determine path(s) satisfied with bandwidth-guaranteed in the Internet, routers should have information on network topology and Link State. The information is stored in Link State Database (LSDB) located in each router and managed. If Link States information is changed, routers inform their neighbor of Link State information changed by sending Link State Update (LSU) messages. However, there is trade-off between reflection of actual Link State information on LSDB and cost of sending LSU messages. To find a bandwidth-guaranteed path effectively, it is important to decide whether LSU messages are sent or not for the change of Link sate. In this paper, we propose a threshold-based LSU algorithm using statistic to effectively decide for sending LSU messages and evaluates its performance by intensive simulations. Simulation results show that the performance of proposed scheme is superior to the existing LSU schemes.

  • an enhanced simple adaptive Link State Update algorithm for qos routing
    IEICE Transactions on Communications, 2007
    Co-Authors: Seunghyuk Choi, Min Young Chung, Mijeong Yang, Jaehyung Park
    Abstract:

    In order to find paths guaranteed by Quality of Service (QoS), the Link State database (LSDB), containing QoS constraint information, and residing in routers, needs to be well managed. However, there is a trade-off between the exact reflection of the current Link status and the Update cost to calculate and maintain this data. In order to perfectly reflect the current Link State, each router immediately notifies its neighbors whenever Link State information changes. However, this may degrade the performance of the router. On the other hand, if current Link State information is not Updated routinely, route setup requests may be rejected because of the discrepancy between the current Link State information and the previously Updated Link State information in the LSDB. Therefore, we need Link State Update (LSU) algorithms making it possible to appropriately Update the LSDB. In addition, to facilitate implementation, they also should have low-complexity and must be adaptive under the variation of network conditions. In this paper, we propose an enhanced simple-adaptive (ESA) LSU algorithm, to reduce the generation of LSU messages while maintaining simplicity and adaptivity. The performance of this algorithm is compared with five existing algorithms by rigorous simulations. The comparision shows that the ESU algorithm can adapt to changes in network conditions and its performance is superior to existing LSU algorithms.

  • Link State Update Algorithm considering Traffic Variation
    The 9th International Conference on Advanced Communication Technology, 2007
    Co-Authors: Hae-won Jung, Min Young Chung
    Abstract:

    Routers determine a routing path considering network topology and Link State information for guaranteeing quality of service (QoS). Therefore, it is important that routers should know Link State information so as to calculate a routing path. However, if routers generate Link State Update messages inordinately, their router performance may be reduced due to the processing burden of Link State Update messages. On the other side, in case that Link State information is not Updated appropriately, route setup requests can be rejected even though there are available routes. In this paper, we propose an algorithm to improve router performance and evaluate the proposed algorithm performance as compared with conventional algorithm by simulations.

  • Performance analysis of an adaptive Link status Update scheme based on Link-usage statistics for QoS routing
    Etri Journal, 2006
    Co-Authors: Mijeong Yang, Hae-won Jung, Min Young Chung, Seunghyuk Choi, Myounghee Jung, Jaehyung Park
    Abstract:

    In the global Internet, a constraint-based routing algorithm performs the function of selecting a routing path while satisfying some given constraints rather than selecting the shortest path based on physical topology. It is necessary for constraint-based routing to disseminate and Update Link State information. The triggering policy of Link State Updates significantly affects the volume of Update traffic and the quality of services (QoS). In this letter, we propose an adaptive triggering policy based on Link-usage statistics in order to reduce the volume of Link State Update traffic without deterioration of QoS. Also, we evaluate the performance of the proposed policy via simulations.

Tee Hiang Cheng - One of the best experts on this subject based on the ideXlab platform.

  • BROADNETS - The Performance of Periodic Link-State Update in Wavelength-Routed Networks
    2006 3rd International Conference on Broadband Communications Networks and Systems, 2006
    Co-Authors: Shu Shen, Gaoxi Xiao, Tee Hiang Cheng
    Abstract:

    Distributed lightpath establishment in wavelength- routed networks requires up-to-date Link-State information to achieve blocking performance target. Invalid routing and wavelength assignment decisions caused by inaccurate Link-State information may degrade network performance significantly as the lightpaths become more and more dynamic. In this paper, we evaluate the performance of periodic Link-State Update, where Link-State information is exchanged between network nodes at regular intervals. By proposing an accurate analytical model as well as by carrying out extensive simulations, we show how different components of network blocking probability are affected by inaccurate information under different traffic loads, and provide insights into the high sensitivity of blocking performance to Link- State Update interval under light traffic loads. We demonstrate how the sensitivity could be affected by network connectivity as well.

  • A novel method of Link-State Update in wavelength-routed networks
    Journal of Lightwave Technology, 2006
    Co-Authors: Shu Shen, Gaoxi Xiao, Tee Hiang Cheng
    Abstract:

    Link-State Update is a critical component of the routing protocol in wavelength-routed networks. High-frequency Updates impose heavy traffic on network control channels as well as excessive burden of electronic processing, while stale Link-State information seriously degrades network performance. Therefore, a tradeoff has to be made between control overhead and network blocking probability. This paper proposes a novel Link-State Update method. By actively regulating the Link-State Update rate, the proposed method efficiently handles the inherent burstiness of Link-State changes without overloading control network with excessive Update messages. To improve the blocking performance under limited control bandwidth, it assigns different types of Updates with different priorities such that the stale Link-State information of more negative impact has a higher chance to be removed. Comprehensive performance evaluations show that the method successfully enforces the control bandwidth quota while achieving much lower blocking probability than existing Link-State Update methods

  • The Performance of Periodic Link-State Update in Wavelength-Routed Networks
    2006 3rd International Conference on Broadband Communications Networks and Systems, 2006
    Co-Authors: Shu Shen, Gaoxi Xiao, Tee Hiang Cheng
    Abstract:

    Distributed lightpath establishment in wavelength- routed networks requires up-to-date Link-State information to achieve blocking performance target. Invalid routing and wavelength assignment decisions caused by inaccurate Link-State information may degrade network performance significantly as the lightpaths become more and more dynamic. In this paper, we evaluate the performance of periodic Link-State Update, where Link-State information is exchanged between network nodes at regular intervals. By proposing an accurate analytical model as well as by carrying out extensive simulations, we show how different components of network blocking probability are affected by inaccurate information under different traffic loads, and provide insights into the high sensitivity of blocking performance to Link- State Update interval under light traffic loads. We demonstrate how the sensitivity could be affected by network connectivity as well.

  • evaluating Link State Update triggers in wavelength routed networks
    Proceedings of SPIE, 2005
    Co-Authors: Shu Shen, Gaoxi Xiao, Tee Hiang Cheng
    Abstract:

    In this paper, we evaluate Link-State Update triggers in wavelength-routed networks. We consider two popular triggers, namely the Absolute Threshold Trigger and the Relative Threshold Trigger. The blocking performance of the two triggers is confirmed to be highly dependent on traffic load. Moreover, it is observed that under light traffic load, blocking performance degrades significantly once the threshold is shifted away from advertising every single Link State change immediately. We expect that the above observation would be of significant importance and would impose a critical challenge to the future development of Link-State Update methods.

  • Evaluating the impact of the Link-State Update period on the blocking performance of wavelength-routed networks
    Optical Fiber Communication Conference 2004. OFC 2004, 2004
    Co-Authors: Shu Shen, Gaoxi Xiao, Tee Hiang Cheng
    Abstract:

    The impact of the Link-State Update period on the blocking performance of wavelength-routed networks is evaluated. We show that exclusive use of wavelengths and wavelength continuity constraint cause the impact to be highly load-sensitive.

Shu Shen - One of the best experts on this subject based on the ideXlab platform.

  • BROADNETS - The Performance of Periodic Link-State Update in Wavelength-Routed Networks
    2006 3rd International Conference on Broadband Communications Networks and Systems, 2006
    Co-Authors: Shu Shen, Gaoxi Xiao, Tee Hiang Cheng
    Abstract:

    Distributed lightpath establishment in wavelength- routed networks requires up-to-date Link-State information to achieve blocking performance target. Invalid routing and wavelength assignment decisions caused by inaccurate Link-State information may degrade network performance significantly as the lightpaths become more and more dynamic. In this paper, we evaluate the performance of periodic Link-State Update, where Link-State information is exchanged between network nodes at regular intervals. By proposing an accurate analytical model as well as by carrying out extensive simulations, we show how different components of network blocking probability are affected by inaccurate information under different traffic loads, and provide insights into the high sensitivity of blocking performance to Link- State Update interval under light traffic loads. We demonstrate how the sensitivity could be affected by network connectivity as well.

  • A novel method of Link-State Update in wavelength-routed networks
    Journal of Lightwave Technology, 2006
    Co-Authors: Shu Shen, Gaoxi Xiao, Tee Hiang Cheng
    Abstract:

    Link-State Update is a critical component of the routing protocol in wavelength-routed networks. High-frequency Updates impose heavy traffic on network control channels as well as excessive burden of electronic processing, while stale Link-State information seriously degrades network performance. Therefore, a tradeoff has to be made between control overhead and network blocking probability. This paper proposes a novel Link-State Update method. By actively regulating the Link-State Update rate, the proposed method efficiently handles the inherent burstiness of Link-State changes without overloading control network with excessive Update messages. To improve the blocking performance under limited control bandwidth, it assigns different types of Updates with different priorities such that the stale Link-State information of more negative impact has a higher chance to be removed. Comprehensive performance evaluations show that the method successfully enforces the control bandwidth quota while achieving much lower blocking probability than existing Link-State Update methods

  • The Performance of Periodic Link-State Update in Wavelength-Routed Networks
    2006 3rd International Conference on Broadband Communications Networks and Systems, 2006
    Co-Authors: Shu Shen, Gaoxi Xiao, Tee Hiang Cheng
    Abstract:

    Distributed lightpath establishment in wavelength- routed networks requires up-to-date Link-State information to achieve blocking performance target. Invalid routing and wavelength assignment decisions caused by inaccurate Link-State information may degrade network performance significantly as the lightpaths become more and more dynamic. In this paper, we evaluate the performance of periodic Link-State Update, where Link-State information is exchanged between network nodes at regular intervals. By proposing an accurate analytical model as well as by carrying out extensive simulations, we show how different components of network blocking probability are affected by inaccurate information under different traffic loads, and provide insights into the high sensitivity of blocking performance to Link- State Update interval under light traffic loads. We demonstrate how the sensitivity could be affected by network connectivity as well.

  • evaluating Link State Update triggers in wavelength routed networks
    Proceedings of SPIE, 2005
    Co-Authors: Shu Shen, Gaoxi Xiao, Tee Hiang Cheng
    Abstract:

    In this paper, we evaluate Link-State Update triggers in wavelength-routed networks. We consider two popular triggers, namely the Absolute Threshold Trigger and the Relative Threshold Trigger. The blocking performance of the two triggers is confirmed to be highly dependent on traffic load. Moreover, it is observed that under light traffic load, blocking performance degrades significantly once the threshold is shifted away from advertising every single Link State change immediately. We expect that the above observation would be of significant importance and would impose a critical challenge to the future development of Link-State Update methods.

  • Evaluating the impact of the Link-State Update period on the blocking performance of wavelength-routed networks
    Optical Fiber Communication Conference 2004. OFC 2004, 2004
    Co-Authors: Shu Shen, Gaoxi Xiao, Tee Hiang Cheng
    Abstract:

    The impact of the Link-State Update period on the blocking performance of wavelength-routed networks is evaluated. We show that exclusive use of wavelengths and wavelength continuity constraint cause the impact to be highly load-sensitive.

Raul Toral - One of the best experts on this subject based on the ideXlab platform.

  • Absorbing phase transition in the coupled dynamics of node and Link States in random networks
    Scientific Reports, 2019
    Co-Authors: Meghdad Saeedian, Maxi San Miguel, Raul Toral
    Abstract:

    We present a stochastic dynamics model of coupled evolution for the binary States of nodes and Links in a complex network. In the context of opinion formation node States represent two possible opinions and Link States represent positive or negative relationships. Dynamics proceeds via node and Link State Update towards pairwise satisfactory relations in which nodes in the same State are connected by positive Links or nodes in different States are connected by negative Links. By a mean-field rate equations analysis and Monte Carlo simulations in random networks we find an absorbing phase transition from a dynamically active phase to an absorbing phase. The transition occurs for a critical value of the relative time scale for node and Link State Updates. In the absorbing phase the order parameter, measuring global order, approaches exponentially the final frozen configuration. Finite-size effects are such that in the absorbing phase the final configuration is reached in a characteristic time that scales logarithmically with system size, while in the active phase, finite-size fluctuations take the system to a frozen configuration in a characteristic time that grows exponentially with system size. There is also a class of finite-size topological transition associated with group splitting in the network of these final frozen configurations.

  • Absorbing phase transition in the coupled dynamics of node and Link States in random networks
    arXiv: Physics and Society, 2018
    Co-Authors: Meghdad Saeedian, Maxi San Miguel, Raul Toral
    Abstract:

    We present a stochastic dynamics model of coupled evolution for the binary States of nodes and Links in a complex network. In the context of opinion formation node States represent two possible opinions and Link States a positive or negative relation. Dynamics proceeds via node and Link State Update towards pairwise satisfactory relations in which nodes in the same State are connected by positive Links or nodes in different States are connected by negative Links. By a mean-field rate equations analysis and Monte Carlo simulations in random networks we find an absorbing phase transition from a dynamically active phase to an absorbing phase. The transition occurs for a critical value of the relative time scale for node and Link State Updates. In the absorbing phase the order parameter, measuring global order, approaches exponentially the final frozen configuration. Finite size effects are such that in the absorbing phase the final configuration is reached in a characteristic time that scales logarithmically with system size, while in the active phase, finite-size fluctuation take the system to a frozen configuration in a characteristic time that grows exponentially with system size. There is also a finite-size topological transition associated with group splitting in the network of these final frozen configurations.

Hae-won Jung - One of the best experts on this subject based on the ideXlab platform.

  • Inter-Domain QoS Routing Scheme using Link State Information
    2008 10th International Conference on Advanced Communication Technology, 2008
    Co-Authors: Hae-won Jung, Min Young Chung
    Abstract:

    In the Internet, in order to guarantee Quality of Service (QoS), all routers have to manage their Link State Databases (LSDBs) and determine a routing path that satisfies service requirements based on the LSDB. In addition, routing protocols have to provide QoS not only in the intra- domain but also in the inter-domain to enable the end to end QoS guarantee. In the intra-domain routing, it is possible that a router manages its LSDB because the Link State information is small in a domain. On the other hand, in inter- domain routing, since the amount of the Link State information is very large, it is unrealistic to manage the whole Link State information. The Border Gateway Protocol (BGP) is the most prominent inter-domain routing protocol in the current internet. However, it is difficult to guarantee the inter-domain QoS using BGP because the BGP is a path- vector based protocol. In this paper, we propose the inter- domain QoS routing schemes that can manage the LSDBs effectively and minimize a waste of the network system resources by Link State Update (LSU) massages. We evaluate the performance of the proposed schemes by simulations. From the results, the proposed schemes can reduce the blocking probability and amount of the Link State Update with a few Link State information.

  • Link State Update Algorithm considering Traffic Variation
    The 9th International Conference on Advanced Communication Technology, 2007
    Co-Authors: Hae-won Jung, Min Young Chung
    Abstract:

    Routers determine a routing path considering network topology and Link State information for guaranteeing quality of service (QoS). Therefore, it is important that routers should know Link State information so as to calculate a routing path. However, if routers generate Link State Update messages inordinately, their router performance may be reduced due to the processing burden of Link State Update messages. On the other side, in case that Link State information is not Updated appropriately, route setup requests can be rejected even though there are available routes. In this paper, we propose an algorithm to improve router performance and evaluate the proposed algorithm performance as compared with conventional algorithm by simulations.

  • Performance analysis of an adaptive Link status Update scheme based on Link-usage statistics for QoS routing
    Etri Journal, 2006
    Co-Authors: Mijeong Yang, Hae-won Jung, Min Young Chung, Seunghyuk Choi, Myounghee Jung, Jaehyung Park
    Abstract:

    In the global Internet, a constraint-based routing algorithm performs the function of selecting a routing path while satisfying some given constraints rather than selecting the shortest path based on physical topology. It is necessary for constraint-based routing to disseminate and Update Link State information. The triggering policy of Link State Updates significantly affects the volume of Update traffic and the quality of services (QoS). In this letter, we propose an adaptive triggering policy based on Link-usage statistics in order to reduce the volume of Link State Update traffic without deterioration of QoS. Also, we evaluate the performance of the proposed policy via simulations.

  • Adaptive Threshold-based Link Status Update Mechanism
    2006 8th International Conference Advanced Communication Technology, 2006
    Co-Authors: Hae-won Jung, Min Young Chung
    Abstract:

    The current Internet Protocol (IP)-based networks face tremendous requirements such as Quality of Service (QoS) guarantees, efficient Traffic Engineering (TE), network scalability, and high network performance, in accordance with the emergence of diverse Internet services. A constraint-based routing path is determined based on network topology and Link State information to guarantee QoS. It is necessary for constraint-based routing to disseminate and Update Link State information. Throughput can be reduced due to processing Link State Update messages if Link Update messages are generated excessively. On the other side, route setup requests can be rejected even though there are available routes in case that Link State information is not Updated appropriately. This paper proposes a new adaptive threshold-based Link status Update mechanism to reduce the volume of Link State Update traffic and to provide QoS-guaranteed path. In addition, the performance of the proposed mechanism is evaluated via simulations.

  • Adaptive Threshold-based Link Status Update Mechanism
    2006 8th International Conference Advanced Communication Technology, 2006
    Co-Authors: Hae-won Jung, Min Young Chung
    Abstract:

    The current Internet protocol (IP)-based networks face tremendous requirements such as quality of service (QoS) guarantees, efficient traffic engineering (TE), network scalability, and high network performance, in accordance with the emergence of diverse Internet services. A constraint-based routing path is determined based on network topology and Link State information to guarantee QoS. It is necessary for constraint-based routing to disseminate and Update Link State information. Throughput can be reduced due to processing Link State Update messages if Link Update messages are generated excessively. On the other side, route setup requests can be rejected even though there are available routes in case that Link State information is not Updated appropriately. This paper proposes a new adaptive threshold-based Link status Update mechanism to reduce the volume of Link State Update traffic and to provide QoS-guaranteed path. In addition, the performance of the proposed mechanism is evaluated via simulations