Young Boo Kim

A Design of Network Simulation Environment Using SSFNet

Network simulation tool is needed to verify the functionalities and performance of networks. The SSFNet (Scalable Simulation Framework Network Models) is a network simulation tool using open source software with various network simulation applications. It has been designed for the expansion of network including topology, protocols, traffic, and etc, and is able to support simulation for the large-scale network like Internet. However it is not easy for general users to perform network simulation using SSFNet because the SSFNet does not provide users with any supplementary tools for designing of network elements and topology, and analyzing of simulation results. The network modeling and analysis process must be done manually by users themselves. This circumstance makes it difficult to perform reliable network simulation. In this paper, we design a network simulation environment available for SSFNet. Using this environment, users can build network simulation model effectually and analyze the simulation results without difficulty.

An architecture of scalable ATM switching system and its performance

In this paper, we present the basic idea and some concepts for the architecture of the ATM switching system being developed in ETRI of KOREA, and also describe its performance. RSE (Reference Service Entity) concept is introduced to define the characteristics of user’s traffic. This concept is useful to represent the demand of CPE (Customer Premise Equipment) user sets and one of point‐to‐multipoint connections. We also propose RUCA (Reference Units for Connection Attempts) concept with which we can illustrate the call/connection level performance of the ATM switching system. This concept can be applied for measuring the call processing capability in both point‐to‐multipoint connections and multipoint‐to‐multipoint connections when call set‐up between users is performed by a sequence of point‐to‐point connections basis. From the basic concepts and the recommendations of ITU‐T, the design objective of the system performance is specified. We represent the methodologies for dimensioning the system to achieve the design objectives, and estimate the system performances. Then we show that our developing system has suitable performance to accommodate the future B‐ISDN.

A flow admission control in Next Generation Networks with flow aggregate information exchange

Next Generation Networks (NGN) is defined as a set of multi-access, multi-transport, multi-service packet-based networks. There exists a variety of Quality of Service (QoS) architectures within NGN, therefore it is common to aggregate and de-aggregate flows at the boundaries of networks. A key question arises regarding the network performance is therefore whether we can guarantee end-to-end performance in this circumstance. In this work an efficient method for calculating end-to-end delay bounds of flows is given, which experience repetitive flow aggregations and de-aggregations. The calculation procedure requires network parameters exchanged among networks in the path as well as the traffic parameters of a flow. It is assumed that such parameters are exchanged according to a standard process recently approved in ITU-T. It is then suggested a simple admission control scheme for flows with strict delay bound requirements. In this scheme aggregation edge nodes store information only per flow aggregate; therefore the scalability is ensured. The delay bound and the admission control scheme are evaluated with simulations in a few realistic scenarios.

Philosophy & key design principles of BcN as an enhanced NGN

Existing Internet has problem in many areas such as reliability, service availability, and manageability. Active research has been done to solve this problem. In Korea, BcN was developed to solve the well known Internet problem and to achieve the fixed-mobile convergence services. This paper explains the philosophy and design principles of BcN architecture. We first explains the background of BcN activities and its key result of BcN. We then also introduce the design principle of BcN architecture. We also present the overview of the BcN architecture and briefly describe the issues and our approaches.