You-Hyeon Jeong

A Scalable and Highly Available Network Management Architecture on Consistent Hashing

To devise a large-scale network management system, we should consider following issues: heterogeneity of network devices, interoperation between multiple network domains, scal- ability and availability of the management system, and the cost of developing and deploying the system. Traditional network management software does not provide a cost-effective solution for the above issues because they are usually designed for a specific network domain composed of a limited set of network devices, and they have a complex multi-tiered architecture that usually requires a separate failover scheme and development strategy for each tier at the additional costs of development, deployment, and operation. In this paper, we propose a novel network management architecture, CORD, based on consistent hashing. CORD achieves scalable load balancing and sub-50ms failover performance against a node failure with a one-tired architecture. Using XML, CORD provides highly-customizable southbound management interface which integrates network devices from multiple vendors with ease. With the experiments, we have shown that the standard deviation of load balancing on CORD nodes is maintained around 5% and the failover time is below 50ms on average. In addition, we have applied CORD to the optical network management system development to reduce CAPEX and OPEX.

Implementation of inter-domain path computation element

The Path Computation Element (PCE) Working Group (WG) at the Internet Engineering Task Force (IETF) is chartered to specify a PCE-based architecture for the path computation of inter-domain MPLS/GMPLS-based traffic engineered Label Switched Paths (LSPs). The PCE architecture introduces a special computational entity that will corporate with similar entities to compute the best possible path through single or multiple domains. This paper presents the state-of-the-art in PCE and several topics (e.g. PCE discovery mechanism, inter-domain path computation). In this paper, we describe the details about our PCE implementation.

Study of High-Speed NGN Resource Control Schemes

Next generation network (NGN) is a packet-based converged network to support session and non-session services in QoS-enabled broadband transport network. QoS based resource control must be defined to support differentiated services for various network users in NGN. This paper defined parallel control schemes for NGN resource control interfaces to minimize session and resource control delays. We simulated the existing and proposed NGN control schemes to measure and analyze control delays and completion ratios. By arrival rate of 120 in two-phase resource control, we checked out that completion ratios of sequential and parallel schemes achieved 100%, and the control delay of parallel scheme was improved by about 21.5% compared to that of sequential scheme.

A Secure and Scalable Transaction Protocol for Ubiquitous Sensor Network using RFID Systems

The RFID technology has ample growth potential since it can be applied to practically all areas, ranging from retail and logistics sectors to livestock management, home network systems, traffic control and hospital patient management. With the advent of this technology, it is possible to realize ubiquitous sensor network (USN) such that every object is given an RFID tag giving them a digital identity, so-called ubiquitous tag or ubiquitous sensor. However, it is clear that the biggest challenge for RFID technology is to provide benefits without threatening the privacy of information. Many solutions have been suggested for RFID systems, but none of them suits to the USN environment because of their security weakness or non-scalability. In this paper, we propose a secure and scalable transaction (SST) protocol for USN using RFID technology. The SST protocol uses the advanced encryption standard (AES) algorithm for authentication and encryption so that it can be free from tag cloning and privacy attack. Moreover, it is scalable in a sense that an RFID reader does not need to perform a shared key distribution and management. In analyzing SST protocol, we show how forward privacy is guaranteed and demonstrate the results.

A CMQ Middleware Architecture for Multimedia Application in Ubiquitous Environment

Traditional applications are executed using the restricted resources of a single computer, do not consider contextual information, and can not support mobile users. However, ubiquitous applications provide optimal services for mobile users using the various resources of computers and the contextual information around users and devices. Thus, ubiquitous applications need to have the functionality of context awareness, user mobility and QoS adaptability. This paper design the CMQ (context-aware, mobility -aware, QoS-aware) middleware framework for ubiquitous applications and implement the middleware framework using Jini and Java. The implemented middleware system can process various contexts, provide the session handoff for a mobile user, and allow applications to adjust its QoS dynamically

Standardization efforts in optical networking focused on architecture and signaling issues

This paper summarizes the present state of optical networking, whereabouts of the optical network by which IP-centric networks carry the traffic. By start out from the assuming that the Internet transport infrastructure is moving towards a model of high speed routers interconnected by optical core networks, various technical issues mainly on optical network architecture and signaling standardization trends are presented in this article. Also, the author present the concepts of generalized multiprotocol label switching (GMPLS) in accordance to the future direction of deploying the IP over optical networks.

Mapping of QoS Information Elements and Implementation of Rs/Rw Interface Resource Control Protocols in NGN

NGN is a packet-based converged network to support session and non-session services in QoS-enabled broadband transport network. QoS based resource control must be defined to support differentiated services for various network users in NGN. We designed and implemented DIAMETER protocol as the Rs interface, and also defined mapping rules between DIAMETER information elements and SDP(Session Description Protocol) attributes for QoS based resource control in NGN. We selected and implemented DIAMETER protocol among alternate resource control protocols in ITU-T as the Rw interface because of simple interworking method with Rs interface and adequate AAA functionality. We defined mapping rules of messages and information elements between Rs and Rw interfaces for resource control from a service layer to a transport layer. Based on the mapping rule of QoS information elements and the interworking method between Rs and Rw interfaces, we built up a test-bed that support differentiated delivery services.

Routing information collector for Path Computation Element

In this paper, we present the design and the implementation of OSPF-TE routing information collector for MPLS and GMPLS networks. OSPF is commonly used as an IGP in MPLS and GMPLS networks to determine the topology over which LSPs can be established. TE extensions have been recently enabled in OSPF to support SPF tree calculation upon different purposes, thus possibly achieving optimal path computation and helping improve resource utilization efficiency. The IETF has standardized the PCE-based architecture, a good candidate to perform multidomain path computation. In such an architecture, the PCE needs the TED to compute the paths requested by a PCC. In this paper, we explain the approaches of using a OSPF-TE for the building and maintenance of the TED.

Policy Definition for Bottom-Up Recovery Scheme in Multilayer Network

For self-healing network, it is essential to deploy coordinated recovery scheme among several layers in multilayer network. By doing root-cause analysis of failures, network recovery function can be performed in the origin layer causing other failures on several layers, and as a result of this recovery function, the damage like service interruption can be prevented or minimized. This paper proposes multilayer network recovery scheme and policies, in which root-cause analysis is integrated with hold-off time of bottom-up recovery scheme.

High-Speed Control Mechanisms in NGN Rs and Rw Interfaces

Next generation network (NGN) is a packet-based converged network to support session and non-session services in QoS-enabled broadband transport network. QoS based resource control must be defined to support differentiated services for various applications in NGN. This paper defined parallel control mechanisms for NGN resource control interfaces to minimize session and resource control delays. We simulated the existing sequential mechanism and our proposed parallel mechanism to measure and analyze control delays and completion ratios.