Daniel Won-Kyu Hong

A QoS management framework for distributed multimedia systems

This paper proposes a high-performance connection management architecture to design a common QoS framework applied to an ATM network based on the Open Distributed Processing (ODP) concept. We design the QoS framework in accordance from the RM-ODP information and computational viewpoints.

A Segment-based Protection Scheme for MPLS Network Survivability

This paper proposes a new approach, segment-based path protection, which provides much more enhanced network resource utilization than the local protection scheme and achieves much more fast restoration than the global protection scheme. This segment-based protection scheme consists of two subsequent steps: determination of the optimal restoration scope taking the working path state, bandwidth, and delay constraints into account and calculation of optimal segmented backup path that is link and node disjoint path with the found working path. In addition, we evaluate the performance of the proposed protection scheme under the randomly generated Waxmans network topology

An integrated network management framework for Internet access service using ATM over ADSL technology

We propose an integrated network management framework for Internet access service using ATM over ADSL technology. There are two distinct networks of ATM and Internet. Most of the routers in the Internet are connected with WDM. The network access server (NAS) in the Internet provides the Internet access service for the ATM over ADSL subscriber. The ATM network takes the roles of backbone network for the pure ATM PVC and SVC services and the access network for the ATM over ADSL service. In order to define the generic network model that can be commonly applicable for the backbone network for pure ATM service and the access network for ATM over ADSL service taking into account the scalability, we suggest two fragments of the topological fragment and connectivity fragment to maximize the scalability in accordance with the ITU-T G805 layering and partitioning concepts and the RM-ODP information viewpoint. In addition, we propose the distributed computational model of the ATM over ADSL network management system using the RM-ODP computational viewpoint and TMN functional decomposition of FCAPS taking into account the functional distribution and the modularity. Lastly, we describe the scenario for providing the Internet access service.

A rerouting scheme with dynamic control of restoration scope for survivable MPLS network

This paper proposes a rerouting scheme that can be applied to the restoration of working Label Switched Paths (LSPs) and preprovisioned backup LSPs, which consists of two subsequent algorithms. The first algorithm for the dynamic deterimination of the restoration scope (RS)increases the restoration speed by minimizing the complexity of the network topology and by maximizing the reusability of the existing working LSP. The second newly proposed concept of RS extension minimizes the probability of restoration failure by dynamically widening the restoration scope until the RS is equal to the whole network topology. Through simulation, we evaluate the performance of our restoration scheme and the existing protection schemes in terms of the restoration speed, packet loss, network resource utilization, and resource reusability of the existing working LSP.

A Flow-Through Workflow Control Scheme for BGP/MPLS VPN Service Provision

In a competitive telecommunications marketplace, operators must provide customers with rapid access to both new and traditional service offerings. Market share is developed through greater customer satisfaction and by reducing dissatisfaction. To maximize profitability, an operator must reduce the costs of delivering new services while building revenues from existing services. This paper proposes a workflow-based service delivery architecture for telecommunications services. We describe an business process management in telecommunications and propose the workflow patterns that are commonly applicable for the workflow management of the proposed telecommunications architecture. In addition, this paper proposes an XML-based workflow control scheme incorporating the workflow patterns for providing telecommunications services. Finally, we describe a scenario for the delivery of the BGP/MPLS VPN service adopting the proposed workflow-based service delivery architecture.

An integrated service and network management system for point-to-multipoint reservation service in an ATM network

This paper describes an integrated service and network management system for provisioning the point-to-multipoint reservation service (PMRS) in an ATM network. There are two major issues confronting the network service provider in relation to this service: one is to rapidly confirm the acceptability of the subscribers reservation at subscription time, and the other is to punctually activate the reserved point-to-multipoint service. To meet these requirements, this paper proposes a service provision model (SPM) and a network resource model of bandwidth allocation timetable (BAT). This paper likewise proposes a point-to-multipoint routing algorithm composed of ordering and backtracking procedures, which can find an optimal branch point under the complex network topology and can add more destinations to the existing point-to-multipoint route. Lastly, this paper shows the feasibilities of the SPM, the BAT and the point-to-multipoint routing algorithm by means of implementation and performance analysis under the real ATM network of Korea Telecom.

Distributed networking system for Internet access service

The number of ADSL subscribers in Korea Telecom is remarkably increasing by as many as eight hundred new subscribers every day, with a total number now already at 3 million. Because of such a large number of customers, we need a systematic networking system that can easily accommodate the explosive growth in the number of ADSL subscribers, and efficiently and uniformly manage the various heterogeneous network equipments that are increasing in proportion to the growth of ADSL subscribers. This paper, thus, proposes the distributed networking system architecture for Internet-access service provision using ATM over ADSL. In this paper, we describe the hierarchical network model in deploying ADSL services across the ATM access networks, which can easily accommodate the explosive growth ADSL subscribers in the future. In addition, this paper describes the distributed networking system and its capability to provide a systemic network management using the principal networking concepts of service ordering, addressing, routing, adaptation and switching. All of the networking system components with CORBA objects in favor of the distribution and location transparency are defined and described using the CORBA interface description language (IDL) for commonality. Lastly, we present its implementation and operation in Korea Telecom.

A Hierarchical LSP Management Architecture for MPLS Traffic Engineering

In this paper, we propose a scalable Label Switched Path (LSP) management architecture for Multiprotocol Label Switching (MPLS) traffic engineering using a hierarchical network model. MPLS introduces the concept of a label hierarchy to support scalability by lessening the complexity of transit routers for the computation of complete routing tables. However, this hierarchical network model creates a critical disadvantage in providing a globally-optimal route because of topology abstraction or aggregation. This paper proposes a hierarchical routing scheme that can provide a globally-optimal route in hierarchical MPLS networks using propagation from the Condensed Subordinate Route Information (CSRI). CSRI is summarized route information among border nodes in the lower layer network and is reflected in the process of the LSP path computation in the higher layer network. We also propose the algorithms for generation of CSRI, for reflection CSRI to higher layer network topology, and for computation of an optimal LSP in a higher layer.

A configuration algorithm for provisioning of cell-based MPLS network

This paper proposes a configuration algorithm of multipoint-to-point connection for facilitating VC merge concept in an MPLS over ATM network. This configuration solves two major problems: determining the most reasonable candidate ATM switch served as an ATM-LSR under the complex ATM network topology; and providing the most reasonable multipoint-to-point connections with regards to network resource utilization. This algorithm is therefore subsequently composed of two procedures: ordering and backtracking. The ordering algorithm is for determining the orders of link and node taking the routing metrics of available bandwidth delay and hop count into account. The backtracking algorithm is to determine the optimal multipoint-to-point route based on the order information allocated by ordering algorithm. We evaluate the proposed algorithms under the operational network environment of KT.

A configuration algorithm for supporting VC-merge concept under the cell-based MPLS network

This paper proposes a configuration algorithm for determination of best VC-merge point under the cell-based MPLS network. This configuration algorithm solves two major problems: determining the most reasonable candidate ATM switch served as an ATM-LSR under the complex ATM network topology; and providing the most reasonable multipoint-to-point connections for deployment of cell-based MPLS network taking into account network resource utilization. This algorithm is subsequently composed of two procedures: ordering and backtracking. The ordering algorithm is for determining the orders of link and node taking the routing metrics of available bandwidth delay and hop count into account. The backtracking algorithm is to determine the best multipoint-to-point route based on the order information allocated by ordering algorithm. In addition, this paper describes the performance evaluation result of the proposed algorithms under the operational network environment of KT (Korea Telecom).