• Title/Summary/Keyword: Adaptive delay threshold

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A Feedback Control Model for ABR Traffic with Long Delays (긴 지연시간을 갖는 ABR 트래픽에 대한 피드백제어 모델)

  • O, Chang-Yun;Bae, Sang-Hyeon
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.4
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    • pp.1211-1216
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    • 2000
  • Asynchronous transfer mode (ATM) can be efficiently used to transport packet data services. The switching system will support voice and packet data services simultaneously from end to end applications. To guarantee quality of service (QoS) of the offered services, source rateot send packet data is needed to control the network overload condition. Most existing control algorithms are shown to provide the threshold-based feedback control technique. However, real-time voice calls can be dynamically connected and released during data services in the network. If the feedback control information delays, quality of the serviced voice can be degraded due to a time delay between source and destination in the high speed link. An adaptive algorithm based on the optimal least mean square error technique is presented for the predictive feedback control technique. The algorithm attempts to predict a future buffer size from weight (slope) adaptation of unknown functions, which are used fro feedback control. Simulation results are presented, which show the effectiveness of the algorithm.

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An ABR Service Traffic Control of Using feedback Control Information and Algorithm (피드백 제어 정보 및 알고리즘을 이용한 ABR 서비스 트래픽제어)

  • 이광옥;최길환;오창윤;배상현
    • Journal of Internet Computing and Services
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    • v.3 no.3
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    • pp.67-74
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    • 2002
  • Asynchronous transfer mode (ATM) can be efficiently used to transport packet data services. The switching system will support voice and packet data services simultaneously from end to end applications. To guarantee quality of service (QoS) of the offered services, source rate to send packet data is needed to control the network overload condition. Most existing control algorithms are shown to provide the threshold-based feedback control technique. However, real-time voice calls can be dynamically connected and released during data services in the network. If the feedback control information delays, quality of the serviced voice can be degraded due to a time delay between source and destination in the high speed link, An adaptive algorithm based on the optimal least mean square error technique is presented for the predictive feedback control technique. The algorithm attempts to predict a future buffer size from weight (slope) adaptation of unknown functions, which are used for feedback control. Simulation results are presented, which show the effectiveness of the algorithm.

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A SIP INVITE Flooding Detection algorithm Considering Upperbound of Possible Number of SIP Messages (발생 메시지의 상한값을 고려한 SIP INVITE 플러딩 공격 탐지 기법연구)

  • Ryu, Jea-Tek;Ryu, Ki-Yeol;Roh, Byeong-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.8B
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    • pp.797-804
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    • 2009
  • Recently, SIP(Session Initiation Protocol) is used to set up and manage sessions for multimedia applications such as VoIP(Voice over IP) and IMS(IP Multimedia Subsystem). However, because SIP operates over the Internet, it is exposed to pre-existed internet security threats such as service degradation or service disruptions. Multimedia applications which are delay sensitive even suffers more from the threats mentioned above. The proposed methods so far to detect SIP INVITE flooding are CUSUM(Cumulative Sum), Hellinger distance and adaptive threshold, but among methods only take normal state into consideration. So, it is not capable of adapting the condition of the network congestion which are dynamically changing. In this paper, SIP INVITE flooding detection algorithm considering network congestion which enables efficient detections of such attacks is proposed. The proposed algorithm is expected to detect other types of attacks such as BYE and CANCEL more precisely compared to other methods.