• Title/Summary/Keyword: ATM switch

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The copy networks controlling the copy number according to the fluctuations of the input traffics for an ATM Multicast Switch (입력 트래픽의 특성에 따라 복사 수가 제어되는 ATM 멀티캐스트 스위치 복사 망)

  • Paik, Jung-Hoon;Lim, Chae-Tak
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.10
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    • pp.52-63
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    • 1998
  • In this paper, several improvements to a copy network proposed previously for multicast packet switching are described. The improvements provide a solution to some problems inherent in multicasting. The input fairness problem caused by overf low is solved by a dynamic starting point decider(DSD), which can calculate running sums of copy requests starting from any input port. The starting point is changed adaptively in every time slot based on both the fill level of the input buffers in current time slot and the overflow situations of the previous time slot. Using the fill level of the conventional network. The DSD also provides the function of regulating overall copy requests according to the amount of input traffics. This is an essential function in improving overall throughputs of the copy networks. The throughput of a multicast switch can be improved substantially if partial service of copy request is implemented when overflow occurs. Call-splitting can also be implemented by the DSD in a straightforward manner. The hardware for the DSD is derived with the objective of simple architectures for the high speed operation. Simulation study of the copy network under various traffic conditions is presented to evaluate its performance.

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Design and Implementation for A Scalable Web-Based Distributed Simulator (확장성을 갖는 웹 기반 분산 시뮬레이터의 구현 및 설계)

  • Kim, Jong-Eun
    • Journal of Korea Game Society
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    • v.2 no.1
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    • pp.42-48
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    • 2002
  • Many web-based simulation environments have been proposed to create models and execute simulation through the Web. Although web-based simulation has the advantage of utilizing many computers connected to Internet, overhead of the web server and heavy traffic caused by Java RMI degrade the performance and scalability of simulation. In this paper, we design and implement web-based distributed simulator using Java for the scalability and performance. In addition, we can apply the proposed simulator to create model server and client engines in online game. We apply the proposed simulator to simulate ATM switch queueing model.

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EPGA Implementation and Verification of CSIX Module (CSIX 모듈의 FPGA 구현 및 검증)

  • 김형준;손승일;강민구
    • Journal of Internet Computing and Services
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    • v.3 no.5
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    • pp.9-17
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    • 2002
  • CSIX-L1 is the Common Switch Interface that defines a physical interface for transferring information between a traffic manager (Network Processor) and a switching fabric in ATM, IP, MPLS, Ethernet and data communication areas. In Tx, data to be transmitted is generated in Cframe which is the base information unit and in Rx, original data is extracted from the received Cframe. CSIX-L1 suppots the 32, 64, 96, and 123-bit interface and generates a variable length CFrame and Idle Cframe. Also CSIX-L1 appends Padding byte and supports 16-bit Vertical parity, CSIX-L1 is designed using Xilinx 4,1i. After functional and timing simulations are completed. CSIX-L1 module is downloaded in Xilinx FPGA XCV1000EHQ240C and verified. The synthesized CSIX module operates at 27MHz.

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A cell distribution algorithm of the copy network in ATM multicast switch (ATM 멀티캐스트 스위치에서 복사 네트워크의 셀 분배 알고리즘)

  • Lee, Ok-Jae;Chon, Byoung-Sil
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.8
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    • pp.21-31
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    • 1998
  • In this paper, a new algorithm is proposed which distributes multicast cells in a copy network. The dual copy network is composed of running adder network, distributor, dummy address encoder, and broadcasting network. It is operated lower input address and higher one simultaneously by the distribution algorithm. As a result, for each input has a better equal opportunity of processing, cell delay and hardware complexity are reduced in copy network. Also, for it adopts the broadcasting network from an expansion Banyan network with binary tree and Banyan network, overflow probability is reduced to a half in that network. As a result of computer simulation, the copy network processed by the distribution algorithm is remarkably improved in cell delay of input buffer according to all input loads.

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Performance Analysis of ATM Switch Using Priority Control by Cell Transfer Ratio (셀 전송비율에 의한 우선순위 제어방식을 사용한 ATM 스위치의 성능 분석)

  • 박원기;김영선;최형진
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.12
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    • pp.9-24
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    • 1995
  • In this paper, we proposed and analysed two kinds of priority control mechanism to archive the cell loss rate requirement and the delay requirement of each class. The service classes of our concern are the high time priority class(class 1) and the high loss priority class(class 2). Two kinds of priority control mechanism is divided by the method of storing the arriving class 2 cell in buffer on case of buffer full. The first one is the method which discarding the arriving class 2 cell, the second one is the mothod which storing the arriving class 2 cell on behalf of pushing out the class 1 cell in buffer. In the proposed priority schemes, one cell of the class 1 is transmitted whenever the maximum K cells of the class 2 is transmitted on case of transmitting the class 1 cell and the class 2 cell sequentially. In this paper, we analysed the cell loss rate and the mean cell delay for each class of the proposed priority scheme by using the Markov chain. The analytical results show that the characteristic of the mean cell delay becomes better for the class 1 cell and that of the cell loss rate becomes better for the class 2 cell by selecting properly the cell transfer ratio according to the condition of input traffic.

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A Study on Efficient Transmission Rate Control of ABR Traffic in ATM (ATM 망에서 효율적인 ABR 트래픽 전송률 제어에 관한 연구)

  • 정명수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.9A
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    • pp.1413-1421
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    • 2000
  • In this paper, we analyze previous flow control algorithm for serving ABR traffic, and then propose the algorithm which calculate fair transmission rate and control efficiently ABR traffic using VS/VD switch which has an effect on WAN environment with long delay. For getting the transmission rate, the proposed algorithm use FMMAR as ER scheme which calculate exactly the fair share. And, in large delay state. we can obtain fair cell sharing by calculating transmission rates which obtained by transmitted queue length information of VD to VS for serve and drain cell in queue Through the computer simulation, we evaluate the performance of proposed algorithm. According to the results, the proposed algorithm shows good performance.

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A Study on Predictive Traffic Control Algorithms for ABR Services (ABR 서비스를 위한 트래픽 예측 제어 알고리즘 연구)

  • 오창윤;장봉석
    • Journal of Internet Computing and Services
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    • v.1 no.2
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    • pp.29-37
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    • 2000
  • Asynchronous transfer mode is flexible to support multimedia communication services using asynchronous time-sharing and statistical multimedia techniques to the existing data communication area, ATM ABR service controls network traffic using feedback information on the network congestion situation in order to guarantee the demanded service qualities and the available cell rates, In this paper we apply the control method using queue length prediction to the formation of feedback information for more efficient ABR traffic control. If backward node receive the longer delayed feedback information on the impending congestion, the switch can be already congested from the uncontrolled arriving traffic and the fluctuation of queue length can be inefficiently high in the continuing time intervals, The feedback control method proposed in this paper predicts the queue length in the switch using the slope of queue length prediction function and queue length changes in time-series, The predicted congestion information is backward to the node, NLMS and neural network are used as the predictive control functions, and they are compared from performance on the queue length prediction. Simulation results show the efficiency of the proposed method compared to the feedback control method without the prediction, Therefore, we conclude that the efficient congestion and stability of the queue length controls are possible using the prediction scheme that can resolve the problems caused from the longer delays of the feedback information.

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ABR Traffic Control Using Feedback Information and Algorithm

  • Lee, Kwang-Ok;Son, Young-Su;Kim, Hyeon-ju;Bae, Sang-Hyun
    • Proceedings of the KAIS Fall Conference
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    • 2003.11a
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    • pp.236-242
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    • 2003
  • ATM ABR service controls network traffic using feedback information on the network congestion situation in order to guarantee the demanded service qualities and the available cell rates. In this paper we apply the control method using queue length prediction to the formation of feedback information for more efficient ABR traffic control. If backward node receive the longer delayed feedback information on the impending congestion, the switch can be already congested from the uncontrolled arriving traffic and the fluctuation of queue length can be inefficiently high in the continuing time intervals. The feedback control method proposed in this paper predicts the queue length in the switch using the slope of queue length prediction function and queue length changes in time-series. The predicted congestion information is backward to the node. NLMS and neural network are used as the predictive control functions, and they are compared from performance on the queue length prediction. Simulation results show the efficiency of the proposed method compared to the feedback control method without the prediction. Therefore, we conclude that the efficient congestion and stability of the queue length controls are possible using the prediction scheme that can resolve the problems caused from the longer delays of the feedback information.

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A Study on Design and Implementation of a VC-Merge Capable LSR on MPLS over ATM (ATM기반 MPLS망에서 확장성을 고려한 VC-Merge 가능한 LSR 설계에 관한 연구)

  • Kim, Young-Chul;Lee, Tae-Won;Lee, Dong-Won;Choi, Deok-Jae;Lee, Guee-Sang
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.38 no.12
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    • pp.29-38
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    • 2001
  • Recently, as Internet and its services grow rapidly, IETF(Internet Engineering Task Force) introduced a new switching mechanism, MPLS(Multi-Protocol Label Switching), to solve the problem of the scalability in Internet backbone. In this paper, we implemented the LSR loaded with VC-merging function, which causes LSR's management cost to be significantly reduced. We propose a new VC-merge function which supports differentiated services. In case of network congestion in the output buffer of each core LSR, appling link polices to the output modules of the LSR using the EPD algorithm can prevent the buffer from being overflowed. Simulation was performed for Diffserv by using multiple traffic models and investigated the impact of VC-merge method compared to non VC-merge method. The proposed switch is modeled in VHDL and fabricated using the SAMSUNG $0.5{\mu}m$ SOG process.

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The study on Multicast Cell Scheduling for Parallel Multicast packet switch with Ring Network (링망을 이용한 병렬 멀티캐스트 패킷스위치에서의 멀티캐스트 셀 스케줄링에 관한 연구)

  • 김진천
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.5
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    • pp.1037-1050
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    • 2000
  • A goal of a BISDN network is to provided integrated transport for a wide range of applications such as teleconferencing, Video On Demand etc. There require multipoint communications in addition to conventional point-to-point connections. Therefore multicast capabilities are very essential in multimedia communications. In this paper, we propose a new multicast cell scheduling method on the Parallel Multicast Packet Switch with Ring network: PMRN which are based on separated HOL. In this method, we place two different HOLs, one for unicast cells and the other for multicast cells. Then using non-FIFO scheduling, we can schedule both unicast cells and multicast cells which are available at the time in the input buffer. The simulation result shows that this method reduces the delay in the input buffer and increases the efficiency of both point-to-point network and ring network and finally enhances the bandwidth of the overall packet switch. A goal of a BISDN network is to provided integrated transport for a wide range of applications such as teleconferencing, Video On Demand etc. There require multipoint communications in addition to conventional point-to-point connections. Therefore multicast capabilities are very essential in multimedia communications. In this paper, we propose a new multicast cell scheduling method on the Parallel Multicast Packet Switch with Ring network: PMRN which are based on separated HOL. In this method, we place two different HOLs, one for unicast cells and the other for multicast cells. Then using non-FIFO scheduling, we can schedule both unicast cells and multicast cells which are available at the time in the input buffer. The simulation result shows that this method reduces the delay in the input buffer and increases the efficiency of both point-to-point network and ring network and finally enhances the bandwidth of the overall packet switch.

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