Hongtaek Ju

XML-based configuration management for IP network devices

As the Internet continues to grow, the tasks of operations and management of IP networks and systems are becoming more difficult. Over the past few years, much effort has been given to improve the deficiencies of SNMP, but most have failed to be standardized. One critical deficiency of SNMP is in the area of configuration management. Recent work focuses on the use of XML technology for network and service management as an alternative or complementary approach to SNMP. This article presents the IETFs latest effort, Netconf, which is viewed by many as a promising revolutionary solution for configuration management. To validate this new effort, we present the design and implementation of an XML-based configuration management system based on Netconf. We also discuss our experience with XCMS and make some suggestions for improving the current Netconf protocol.

Correlation analysis of MQTT loss and delay according to QoS level

MQTT is an open protocol developed and released by IBM. To ensure the reliability of message transmission, MQTT supports three levels of QoS. In this paper, we analyze MQTT message transmission process which consists of real wired/wireless publish client, broker server and Subscribe client. By transmitting messages through 3 levels of QoS with various sizes of payloads, we have captured packets to analyze end-to-end delays and message loss.

Interaction Translation Methods for XML/SNMP Gateway

XML-based network management has been proposed as an alternative or to complement SNMP-based network management. But the XML-based network management does not yet provide a method to manage networks equipped with legacy SNMP agents in the integrated management system. This integrated management system must include an XML/SNMP gateway, which translates and relays messages between the XML-based manager and the SNMP agent. In this paper, we propose three methods for interaction translation in the gateway. First, we propose a DOM-based translation, which provides a method for XML-based manager to directly access management information through the standard DOM interfaces. Second, we propose an HTTP-based translation using URI extenstion with XPath and XQuery. Finally, we apply SOAP, which is accepted as a standard protocol for XML, and propose a translation method for the gateway to advertise the translation services to the manager using SOAP RPC. We also compare the advantages and disadvantages of the proposed translation methods.

The Architecture of NG-MON: A Passive Network Monitoring System for High-Speed IP Networks

This paper presents the design of a next generation network traffic monitoring and analysis system, called NG-MON (Next Generation MONitoring), for high-speed networks such as 10 Gbps and above. Packet capturing and analysis on such high-speed networks is very difficult using traditional approaches. Using distributed, pipelining and parallel processing techniques, we have designed a flexible and scalable monitoring and analysis system, which can run on off-the-shelf, cost-effective computers. The monitoring and analysis task in NG-MON is divided into five phases; packet capture, flow generation, flow store, traffic analysis, and presentation. Each phase can be executed on separate computer systems and cooperates with adjacent phases using pipeline processing. Each phase can be composed of a cluster of computers wherever the system load of the phase is higher than the performance of a single computer system. We have defined efficient communication methods and message formats between phases. Numerical analysis results of our design for 10 Gbps networks are also provided.

An embedded Web server architecture for XML-based network management

Embedded Web servers are widely used today for IP-based element management. We present a new management architecture that combines this technology with XML, DOM, and XPath to unify element management and network management. XML is used for both management information modeling and manager-agent communication. By taking advantage of modern Web technologies, the proposed architecture provides a method to develop management applications efficiently and to manage network devices effectively. We also explain how legacy SNMP agents are integrated into our proposed architecture.

An efficient embedded Web server for Web-based network element management

An embedded Web server (EWS) is a Web server that runs on an embedded system with limited computing resources and serves embedded Web documents to a Web browser. By embedding a Web server into a network device, it is possible for an EWS to provide a powerful Web-based management user interface constructed using HTML, graphics and other features common to Web browsers. When applied to embedded systems, Web technologies offer graphical user interfaces which are user-friendly, inexpensive, cross-platform, and network-ready. This paper explores the topic of an efficient and lightweight embedded Web server for Web-based network element management. We present the architecture of an embedded Web server that can provide a simple but powerful API. We also present the design and implementation of POS-EWS, which is an embedded Web server that we have developed for Web-based network element management. As well, we present the results of POS-EWSs performance evaluation and EWS optimization methods in a commercial Internet router.

Towards autonomic handover decision management in 4g networks

Mobility management has become an important issue in 4G networks due to the integration of multiple network access technologies. Traditionally, only the received signal strength has been considered for the vertical handover. However, more considerations will be necessary to satisfy the end users preferences. In this paper, we propose an Autonomic Handover Manager (AHM) based on the autonomic computing concept to decide the best network interface to handover in 4G networks. AHM decides the appropriate policy for the specific service or application without the users intervention using the context information from the mobile terminal, the network and the user. We present the context information and the context evaluation function to decide handover based on the user preferences. We then describe the scenario to validate its feasibility using multimedia conferencing service on the mobile terminal.

A Hybrid Approach for Accurate Application Traffic Identification

The traffic dynamics of the Internets dominant applications, such as peer-to-peer and multimedia, worsen the accuracy of the existing application traffic identification. There is a strong need for both practical and reliable identification methods with proof of accuracy. This paper proposes a hybrid approach of signature matching and session behavior mapping methods for accurate application traffic identification. In particular, the paper explores a priority-based signature matching scheme on early packet samples to replace conventional signature matching. It then uses session relationships to identify application traffic from the remaining, unidentified traffic. In validation, we present the accuracy analysis of applications using the Port Dependency Ratio (PDR) method for simulated traffic as well as real traffic.

OMA DM-based remote software fault management for mobile devices

Mobile devices (e.g. mobile handsets or PDAs) have gained much functionality and intelligence with the growth of mobile network technologies and the increased use of mobile services. As a consequence, mobile devices have become more complex and many related problems have occurred. Specifically, sudden rebooting and freezing problems caused by software faults decrease the availability of the mobile device and cause inconvenience to end-users. To solve such problems, academia and industry have focused on Open Mobile Alliance (OMA) Device Management (DM); this method is the international de facto standard for mobile device management. In this paper, we propose a software fault management method to remotely determine and correct problems of mobile devices based on OMA DM. We present a definition of management objects and a method to collect them from mobile devices using the OMA DM protocol. We also present a method for debugging and correcting software faults using the collected information. Finally, we present a prototype implementation and performance evaluation to validate our proposed method. Results of the performance evaluation show that our proposed method is efficient and scalable in regard to network traffic overhead and response time.

Towards Management Requirements of Future Internet

The Internet is one of the most successful modern technologies; we cannot imagine what our lives would be without the Internet. Despite the huge success of the Internet, many problems such as shortage of IP addresses, insufficient security and performance have emerged because of the increasing worldwide Internet population. Furthermore, the technologies developed to incrementally solve the abovementioned problems are causing new problems. Therefore, a redesign of the Internet architecture must be considered. Many research groups around the world are conducting work on the next version of the Internet architecture, called the Future Internet architecture. In this paper, we propose the management requirements and operations of the Future Internet with regard to the key parameters that are being researched through initiatives of research groups, such as FIND, GENI, FIRE and JGN.