• Title/Summary/Keyword: Buffer management

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Fair delay and loss priority control in ATM networks (ATM 망에서 공평한 지연 및 손실 우선순위 제어)

  • 박창욱;임인칠
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.6
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    • pp.23-32
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    • 1996
  • This paper proposes a new buffer management scheme to service delay-sensitive traffic and loss-sensitive traffic fairly in ATM networks. The proposed scheme uses tow buffers for delay-sensitive traffic and loss-sensitive traffic. To satisfy the average delay time of delay-sensitive traffic, cells in real-time buffer are served first. When congestion occurs in nonreal-time buffer, low loss priority cell in real-time buffer can be pushed out by high loss priority cell in nonreal-time buffer can be transferred to real-time buffer considering threshold value in real-time buffer. Using computer simulation, the existing methods and proposed scheme are compared and analyzed with respect to cell loss rate and average delay time. Simulation results show that the proposed scheme have superior performance to conventional schemes.

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Analysis of Optimal Buffer Capacities in 3-node Tandem Queues with Blocking (3-노(盧)드 유한 버퍼 일렬대기행렬에서의 최적 버퍼 크기에 대한 분석)

  • Seo, Dong-Won
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2005.05a
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    • pp.881-889
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    • 2005
  • In this study, we consider characteristics of waiting times in single-server 3-node tandem queues with a Poisson arrival process, finite buffers and deterministic or non-overlapping service times at each queue. There are three buffers: one at the first node is infinite and the others are finite. The explicit expressions of waiting times in all areas of the systems, which are driven as functions of finite buffer capacities, show that the sojourn time does not depend on the finite buffer capacities and also allow one to compute and compare characteristics of waiting times at all areas of the system under two blocking policies: communication and manufacturing blocking. As an application of these results, moreover, an optimization problem which determines the smallest buffer capacities satisfying predetermined probabilistic constraints on waiting times is considered. Some numerical examples are also provided.

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다수의 동일한 입력원을 갖는 ATM Multiplexer의 정확한 셀 손실 확률 분석

  • Choi, Woo-Yong;Jun, Chi-Hyuck
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1995.04a
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    • pp.435-444
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    • 1995
  • We propose a new approach to the calculation of the exact cells loss probability in a shared buffer ATM multiplexer, which is loaded with homogeneous discrete-time ON-OFF sources. Renewal cycles are identified in regard to the state of input sources and the buffer state on each renewal circle is modelled as a K(shared buffer size)-state Markov chain. We also analyze the behavior of queue build-up at the shared buffer whose distribution together with the steady-state probabilities of the Markov chain leads to the exact cell loss probability. Our approach to obtaining the exact cell loss probability seems to be more efficient than most of other existing ones since our underlying Markov chain has less number of states.

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A Study on Bandwidth and Buffer Management Mechanisms of IP Networks (IP 네트워크의 대역폭 및 버퍼 관리 메커니즘에 관한 연구)

  • Hai, Hoang Dang;Thuong, Pham Van;Hong, You-Sik
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.2
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    • pp.143-149
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    • 2010
  • Bandwidth and Buffer are critical network resources to determine the end-to-end quality of service. In this paper, we investigate several techniques on bandwidth and buffer management and classify them according to the types they used for controlling the throughput of a TCP/IP network. Moreover, in this paper, it present a new approach for modeling the active bandwidth and buffer control mechanisms for TCP/IP networks.

Buffer Management Mechanism Using DT-DFBA Algorithm for GFR Service (GFR 서비스를 위한 DT-DFBA 버퍼관리 메커니즘)

  • 안상규;최승권;신승수;조용환
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.5C
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    • pp.474-485
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    • 2002
  • To keep simplicity that needs for GFR service and improve fairness of FIFO based buffer management algorithm, we propose a new LBO threshold decision mechanism. Proposed mechanism uses dynamic threshold that are adjusted according to the sum of active VC's weight. We reformed DT-DFBA(Differential Threshold-Differential Fair Buffer Allocation) algorithm using proposed LBO threshold decision mechanism with existing DFBA algorithm.

Application of (Max, +)-algebra to the Waiting Times in Deterministic 2-node Tandem Queues with Blocking ((Max, +)-대수를 이용한 2-노드 유한 버퍼 일렬대기행렬에서의 대기시간 분석)

  • Seo Dong-Won
    • Journal of the Korean Operations Research and Management Science Society
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    • v.30 no.1
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    • pp.149-159
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    • 2005
  • In this study, we consider characteristics of stationary waiting times in single-server 2-node tandem queues with a finite buffer, a Poisson arrival process and deterministic service times. The system has two buffers: one at the first node is infinite and the other one at the second node is finite. We show that the sojourn time or departure process does not depend on the capacity of the finite buffer and on the order of nodes (service times), which are the same as the previous results. Furthermore, the explicit expressions of waiting times at the first node are given as a function of the capacity of the finite buffer and we are able to disclose a relationship of waiting times between under communication blocking and under manufacturing blocking. Some numerical examples are also given.

Optimal Buffer and Timeslot Allocation Scheme for Broadband Satellite Networks (광대역 위성 네트워크를 위한 최적 버퍼 및 타임슬롯 할당 체계)

  • Chang Kun-Nyeong;Park You-Jin
    • Journal of the Korean Operations Research and Management Science Society
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    • v.31 no.1
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    • pp.117-129
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    • 2006
  • In this paper, we consider broadband satellite networks using MF-TDMA (Multi-Frequency Time Division Multiple Access) scheme. We analyze the number of expected lost packets in each terminal, and mathematically formulate optimal buffer and timeslot allocation model to minimize the weighted sum of the numbers of expected lost packets. We also suggest optimal buffer and timeslot allocation scheme based on Lagrangean relaxation technique to solve the proposed model in a fast time. Extensive experiments show that the proposed scheme provides encouraging results.

Dynamic Cache Partitioning Strategy for Efficient Buffer Cache Management (효율적인 버퍼 캐시 관리를 위한 동적 캐시 분할 블록교체 기법)

  • 진재선;허의남;추현승
    • Journal of the Korea Society for Simulation
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    • v.12 no.2
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    • pp.35-44
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    • 2003
  • The effectiveness of buffer cache replacement algorithms is critical to the performance of I/O systems. In this paper, we propose the degree of inter-reference gap (DIG) based block replacement scheme that retains merits of the least recently used (LRU) such as simple implementation and good cache hit ratio (CHR) for general patterns of references, and improves CHR further. In the proposed scheme, cache blocks with low DIGs are distinguished from blocks with high DIGs and the replacement block is selected among high DIGs blocks as done in the low inter-reference recency set (LIRS) scheme. Thus, by having the effect of the partitioning the cache memory dynamically based on DIGs, CHR is improved. Trace-driven simulation is employed to verified the superiority of the DIG based scheme and shows that the performance improves up to about 175% compared to the LRU scheme and 3% compared to the LIRS scheme for the same traces.

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Basel III Effects on Bank Stability: Empirical Evidence from Emerging Countries

  • ASGHAR, Muhammad;RASHID, Abdul;ABBAS, Zaheer
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.3
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    • pp.347-354
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    • 2022
  • This article examines the influence of Basel III reforms, risk management, and banking sector efficiency on banks' financial stability in emerging countries. The data for this study is collected from various sources. Based on the GDP classification of IMF, the top 22 countries were selected as the sample. The sampling frame includes all six regions of the world including 482 banks and 3022 observations in total. The empirical analysis is carried out by estimating the random effects models. It is found that the effects of capital buffer, liquidity, and risk management practices are significant on financial stability. It is also noticed that the capital buffer has a constructive and significant influence on financial stability. However, liquidity management shows a mixed impact, as in some countries, its impact is positive and significant while, in other countries, it is insignificant. Risk management practices have an overall positive influence on financial stability in the case of large economies. However, results are insignificant in the case of small economies. Bank-specific variables, namely profitability, size, and efficiency have a positive whereas, loan quality has a negative impact on financial stability in the emerging countries. GDP has a positive impact on financial stability whereas inflation and unemployment both have a negative effect on financial stability.

An Adaptive Network Double Buffer Model for Efficient Memory Resource Usage (메모리 자원 사용 효율성 증진을 위한 적응적 네트워크 이중 버퍼 모델)

  • Choi, Daniel;Lee, Sung-Young
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.11
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    • pp.810-819
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    • 2006
  • This paper proposes an Adaptive Double Buffer Model. As a new FIFO buffer model, this technique minimizes packet losses from network congestion by logically managing buffers. It allocates the spare spaces of non-congested buffers to congested buffers by allowing receive/send buffers to share two queues, and hence it minimizes packet losses. In contrast to the buffer model utilizing a free list, this buffer model can prevent the bubble phenomenon caused by a memory leak and thereby apply to a network buffer in a restricted environment. Also, compared with the model using an way, this model brings maximum 100 percent improvement in accepting packets and compared with the model utilizing a free list, this model has the similar efficiency Results of the performance test on Adaptive Double Buffer Model, shows that this proposed model decreases packet losses and enhances memory efficiency.