• The KIPS Transactions:PartC
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• v.10C no.1
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• pp.51-60
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• 2003

One of the most important matters in designing network and realizing service, is to grip on the traffic characteristics. Conventional traffic prediction and analysis used the models which based on the Poisson or Markovian. Recently, experimental research on the LAN, WAN and VBR traffic properties have been pointed rut that they weren't able to display actual real traffic specificities because the models based on the Poisson assumption had been underestimated the long range dependency of network traffic and self-similar peculiarities, it has been lately presented that the new approach method using self-similarity characteristics as similar as the real traffic models. Therefore, in this paper, we generated self-similar data traffic like real traffic as background load. On the existing ABR congestion control algorithm, we analyzed by classify into ACR, buffer utilization. cell drop rate, transmission throughput with the representative EFCI, ERICA, EPRCA and NIST twitch algorithm to show the efficient reaction about the burst traffic.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.1926-1940
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• 1998

This paper is the part II of research results on the performance evaluation of fully interconnected ATM switch, and includes the performance evaluation results for bursty traffic and nonuniform distribution. The switch model is a fyully interconnected switch type proposed by ETRI and is the proper architecutre for a small-sized switch element. The proposed switch consists of two steps of buffering scheme in the switch fabric in order to effectively absorb the effect of bursty nature of ATM traffic. The switch uses bit addressing method for addressing shcmeme and thus it is easy to implement multicasting function without adding additional functional block. In order to incorporate the bursty nature of traffic in ATM networks, we use IBP(Interrupted Bernoulli Process) model as an input traffic model as well as random traffic model which has been used as a traditional traffic model. In order to design the various scenarios for simulation, we considered both uniform and nonuniform output distribution, and also implemented multicast function. In this paper, we presented the simulation results in diverse environments and evaluated the performance of the switch.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.963-966
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• 2003

IPv6-IPv4 변환시스템은 기존의 IPv4 네트워크와 신규 구축되는 IPv6 네트워크 간의 통신을 가능하게 하는 게이트웨이 기반 기술이다. 이러한 IPv6-IPv4 변환시스템에서는 네트워크 간의 모든 트래픽을 변환해야 하므로 높은 성능을 요구된다. 이에 본 연구에서는 이전 연구에서 구현된 게이트웨이 기반 IPv6-IPv4 변환시스템과 변환기의 성능분석에 적용될 수 있는 큐잉 모델을 제시하고 부과되는 트래픽에 따른 처리 성능을 산출하는 분석적인 방법을 제시하였다. IPv6-IPv4 변환시스템의 분석 모델의 경우, 도착간격은 지수분포를 따르고, 서비스시간은 M/M/l/K 모델 기반의 일반분포를 따른다. 또한 IPv6-IPv4 변환시스템의 변환기는 트래픽에 대한 변환 처리를 담당하는 핵심 모듈로서, 순차적인 단계로 이루어진다. 즉, 변환시스템의 변환기 자체의 분석 모델의 도착간격은 지수분포를 따르고, 서비스시간은 M/G/l/K 모델 기반의 일반분포를 따른다. 이렇게 제안된 모델에 대해 상세하게 설명하였으며, 이를 검증하기 위해서 모델을 적용하여 근사한 결과와 실제 측정 결과를 비교하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.1899-1906
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• 1998

In ATM switching system link bandwidth is one of the improtant resources. Thus ATM switching system must allocate the bandwidth to the users efficiently and guarantee the QoS. Especially to guarantee the QoS of the VBR traffic source such as video, users must declare the traffic characteristics and QoS expectations using UPC parameters. The CAC can use two multiplexig models in variation to link capacity and connection number. One is loseless multiplexing model; the second is a statistical multiplexing model. The loseless multiplexing model performs best when the number of mutiplexed sources is small, but as the number of multiplexed sources is increase the CAC must use the statistical multiplexing model. In this paper, the statistical multiplexing models are studied, which are suitable for high capacity ATM link on VBR traffic sources. The satistical multiplexing model and the loseless multiplexing model are combined. In statistical model we map the UPC parameters provided by new VBR connection to appropriate source traffic model. In the high capacity ATM link, as the connection number increases, the statical multiplexing gain increases.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8B
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• pp.699-706
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• 2003

This paper is to verify that 2-state MMPP Model conform to ATM VBR traffic characteristics by measuring and analyzing real-time VBR traffic in KT's ATM network. As a result, we validated the fact that real-time VBR traffic of ATM network cannot be apply to MMPP model and must be represented by previously general On-Off Model with characteristics as follows: arrival rate of On state (λ$_1$) is deterministic, arrival rate of Off state (λ$_2$) is zero, and two transition rate (T$_1$,T$_2$) is only random variable. As research results are to handle real traffic, these results can be used to all ATM network traffic model with traffic management function such as KT's ATM network.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.136-138
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• 2003

빠른 속도와 넓은 대역폭을 이용한 멀티미디어 데이터 전송이 가능하게 됨으로써 패킷 스위칭 네트워크로부터 발생되는 트래픽은 burstiness 성질을 보여준다. 이러한 트래픽은 전통적인 해석적 방법에서 네트워크의 성능평가를 위해 사용되고 있는 트래픽 모델과는 상당히 다른 self­similar 트래픽 성질을 갖고 있다는 것이 실제 트래픽을 측정한 결과 나타나고 있다. 일반적으로 ATM 스위치는 패킷을 효율적으로 전송하기 위해 다양한 공유 버퍼관리 방법을 적용한다. 따라서 본 논문에서는 공유 버퍼를 사용하여 다중 스위치로 상호 연결된 ATM 스위치에서 self­similar 트래픽이 이웃 스위치들 간에 미치는 영향을 통하여 초고속 네트워크의 성능을 분석한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.113-116
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• 2017

최근 급격히 증가한 모바일 기기와 Over The Top (OTT) 서비스의 활성화로 인하여 CMM 기반의 LTE/EPC 네트워크에 과다한 데이터/제어 트래픽의 수용이 힘들어지는 문제가 중요 이슈로 부각되고 있다. 이를 해결하기 위하여 IETF는 Distributed Mobility Management (DMM) 기반의 이동성 관리 방안을 제안하였다. 하지만 DMM 기술은 중앙의 트래픽 부하 분산에 초점을 두고 있어 단말의 이동과 관련하여 발생하는 과다한 제어 트래픽 수용에 관한 문제를 해결하기에는 부족하다. 따라서 본 논문에서는 이러한 문제를 해결하기 위하여 SDN 기반으로 CMM과 DMM을 함께 이용하는 HMM (Hybrid Mobility Management) LTE/ECP 네트워크 모델을 제시한다. 또한 HMM 기반의 LTE/EPC 네트워크 모델은 CMM 및 DMM 기법의 선택을 위해 단말의 이동성과 PDN 연결의 개수를 고려한 선택방안을 제시하며, 제안하는 HMM 기반의 LTE/EPC 네트워크 구조에서의 데이터 트래픽 부하량과 단말의 이동성과 PDN 연결 개수에 따라 제어 트래픽의 양을 비교하는 그래프를 제시하며 제안하는 네트워크 모델의 타당성을 입증한다.

• The KIPS Transactions:PartC
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• v.10C no.4
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• pp.471-478
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• 2003

Traditionally,, analysis, simulation and measurement have all been used to evaluate the performance of network protocols and functional entities that support mobile wireless service. Simulation methods are useful for testing the complex systems which have the very complicate interactions between components. To develop a mobile call simulator which is used to examine, validate, and predict the performance of mobile wireless call procedures must have the teletraffic model, which is to describe the mobile communication environments. Mobile teletraffic model is consists of 2 sub-models, traffic source and network traffic model. In this paper, we analyzed the network traffic data which are gathered from selected Base Stations (BSs) to define the mobile teletraffic model. We defined 4 types of cell location-Residential, Commercial, Industrial, and Afforest zone. We selected some Base Stations (BSs) which are represented cell location types in Seoul city, and gathered real data from them And then, we present the call rate per hour, cail distribution pattern per day, busy hours, loose hours, the maximum number of call, and the minimum number of calls based on defined cell location types. Those parameters are very important to test the mobile communication system´s performance and reliability and are very useful for defining the mobile network traffic model or for working the existed mobile simulation programs as input parameters.

• The Journal of the Korea Contents Association
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• v.5 no.3
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• pp.175-181
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• 2005

Recent measurements of local-area and wide-area traffic have shown that network traffic exhibits at a wide range of scales-Self-similarity. Self-similarity is expressed by long term dependency, this is contradictory concept with Poisson model that have relativity short term dependency. Therefore, first of all for design and dimensioning of next generation communication network, traffic model that are reflected burstness and self-similarity is required. Here self-similarity can be characterized by Hurst parameter. In this paper, when different many data traffic being integrated under various environments is arrived to communication network, Hurst Parameter's change is analyzed and compared with simulation results.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.235-237
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• 2003

멀티미디어 데이터 전송이 가능한 초고속 통신망의 발달로 음성을 위주로 서비스하던 과거와는 다른 self-similar 특성을 갖는 데이터 트래픽이 발생된다는 것이 알려지고 있다. 이러한 트래픽은 전통적인 네트워크 해석 방법인 포와송 트래픽 모델과는 상당히 차이가 난다는 것이 여러 트래픽의 측정 결과 나타나고 있다. 본 논문에서는 공유 메모리를 갖는 CS(Complete Sharing), DT(Dynamic Threshold), PO(Push-Out) 그리고, SMXQ(Sharing with Maximum Queue)와 같은 다양한 ATM(Asynchronous Transfer Mode) 스위치의 버퍼 관리 기법을 이용하여 입력포트에 self-similar 성질을 갖는 트래픽이 들어올 때 출력포트에서의 self-similarity와 셀 손실률 그리고, 이용률 등을 분석한다.