Yu-Ben Miao

Smart Tunnel Union for NAT Traversal

Network address translator (NAT) is the well-known, transitional method to mitigate the problem of IPv4 address depletion in todays Internet. However, the assignment, translation, and export of address/port in a NAT at run time affect application functions. Accordingly, application servers behind the NAT cannot accept requests directly from public networks. Sensitive applications cannot hold their end-to-end security mechanisms. Applications lose connections after the NAT reboots or changes the binding address/port. However, current proposals for NAT traversal hardly solve the problems. Against the problems, we propose Smart Tunnel Union for NAT Traversal (STUNT) in the paper. STUNT permits applications behind the NAT to be actively contacted by Internet clients, keeps end-to-end security mechanisms, and avoids the risk of exporting binding information of the NAT to connection endpoints. Meanwhile, it permits applications to traverse the NAT and keeps the NAT intact

A transparent deployment method of RSVP-aware applications on UNIX

This paper proposes a method, called RLR (RSVP library redirection), which can transform legacy Internet applications into RSVP-aware applications without modifying their source files. RLR achieves the transparent transformation by redirecting procedure calls from the socket library to the RAPI (RSVP application programming interface) library. For UNIX operating systems, such as Linux, Free-BSD etc., the redirection can be realized since the related mechanisms of procedure call interception are supported in these operating systems. In addition to the advantage of transparent transformation, RLR can allow a single RLR software module to be used for multiple programs if they have similar behavior. We have used one RLR module to transform several FTP applications to be RSVP-aware. The experimental results show the feasibility of RLR.

Network Application Programming Interface over Session Initiation Protocol, a novel approach to the global roaming environment

Session Initiation Protocol (SIP) is the most favorable candidate as the mobility management protocol in mobile computing. However, both the application and its developer suffer from inconveniences in utilizing SIP due to lack of a universal interface of SIP. In this paper, the Network Application Programming Interface over Session Initiation Protocol (NAPISIP) is proposed to facilitate using SIP in applications. The NAPISIP has the advantages of supporting concurrent mobility, avoiding application modification, saving application developers from burdens of learning to use SIP, and freeing operating systems from requirements of supporting sophisticated services or Application Programming Interfaces (APIs) to get communication handoff information. The NAPISIP is implemented on Windows 2000 and given experiments. In the experiments with legacy computers, the NAPISIP not only shows a promising performance but also has no drawbacks in Mobile IP when mobile hosts roam through networks.

Session Splice on Multimedia Communication for Mobile Computing

Playing multimedia data with mobile devices is the trend in mobile computing. However, roaming around networks has the session continuity problem because of Internet routing fundamentals. We propose the session splice on multimedia communication for session continuity. It has following advantages: 1) operating without mobile IP nor the triangular route problem, 2) leaving applications unchanged to keep the compatibility, 3) having no need to deploy external proxies, and 4) hiding movements from applications so applications or users do not need to rejoin sessions at the communication handoff. We implement the session splice in windows 2000/XP and have experiments to show that the session splice with the negligible overhead can conserve home network bandwidth and maintain stable variation of packet round trip time

Twin-object platform: a generic proxy-based system for communication customization in mobile computing

Communication customization has been widely used and proved having benefits in mobile computing. However, most systems are designed for specific purposes. They may have weaknesses in compatibility and portability, and incur unnecessary overheads in certain situations. Besides, they may be not flexible as a generic system because of requiring particular software facilities or hardware devices. In the paper, we propose TOP, a generic proxy-based system for communication customization in mobile computing. TOP utilizes API hook and packet redirection technologies to provide objects with the service of packet manipulations. Rather than being limited Java Applet, the objects on TOP are Java application capable of accessing various Java libraries. Communication customization on TOP can fully change an existing protocols semantics without modifying application programs. We implement TOP on Windows 2000/XP and the experiments show that the performance of TOP is acceptable. Besides, we use TOP to overcome TCP disconnection hazards over wireless LAN as an example of applications on it.

Client-side session splice approach, a novel approach to achieving seamless handoffs for multimedia applications in mobile computing

Thanks to the invention of mobile computing technology, people nowadays can have various entertainment experiences with multi-function devices and heterogeneous network interfaces. When using multi-function devices with heterogeneous network interfaces to download and play streaming data, they maybe want to switch the communication from a network interface to another one in a device (i.e., the intra-terminal handoff), or to the network interface in another device (i.e., the inter-terminal handoff). In the handoffs, they have to manually reset or initiate the application, and then re-subscribe to the streaming service because the communication bound to the old network interface is lost. They are interrupted for a long time when watching the show. They have to remember the point or the scene played in the application before the handoff in order to re-subscribe to the streaming service after the handoff. They suffer from the troubling manual operations, especially when the handoff happens frequently to the network interfaces having limited communication ranges. When roaming through networks, accordingly, they need a way to download and play the streaming data without interruption due to handoffs. They can use the proposed Client-side Session Splice Approach (CSSA) to achieve seamless handoffs for multimedia applications in mobile computing. They can rely on the CSSA to automatically finish the handoff between network domains or homogeneous communication media in a network interface, the handoff between network interfaces in a device, and the handoff between network interfaces in different devices. For achieving seamless handoffs, they can count on the CSSA to automatically re-subscribe the streaming service on behalf of the application and smartly download the streaming data at the point or the scene played in the application just before the handoff happens. They don’t need to worry about the compatibility of the CSSA because the CSSA keeps intact applications, network infrastructures, and streaming servers. They can understand the principle, the practicability, the functionality, and the overheads of the CSSA through this paper.

P2PVR: A Networked VCR Service for Live Multimedia Streaming

Multimedia streaming has a tendency to become more and more popular. Many researches focused on this issue, and many peer-to-peer streaming systems were been published. In this paper, we proposed a networked VCR service for live multimedia streaming, called P2PVR. P2PVR treats the entire P2P overlay as a large disk and utilize the storage resource at each participant. P2PVR can support both live streaming and pre-recorded programs. Our experiments show that P2PVR can achieve an acceptable performance with low overhead.

Bottleneck Active Node Detouring for capsule-based active network

Active Node is a network device capable of forwarding packets and giving them the computation service in the meantime. It plays a critical role in capsule-based active networks to speed up the development of a protocol and facilitate the deployment of a service inside networks. When getting overloaded, however, it becomes a throughput bottleneck to all Active Applications whose packets traverse the Active Node. It can enable the Bottleneck Active Node Detouring (BAND) proposed in this paper to free Active Applications from the penalty of poor throughput because not all Active Applications need the computation service in the bottleneck Active Node. Besides, it can enable the BAND to give Active Applications other benefits identified in this paper.

A Novel Approach to Support Mobility Management in Wireless Internet

Multi-layers are involved in the handover procedure when the MN is moving between different networks. In order to ensure proper quality of service for real-time communication in a mobile wireless Internet environment, it is essential to minimize the transient handover delay and packet loss. This paper introduces multilayered techniques to reduce handover latency and packet loss during handover in a SIP-based signaling environment. In this article, a new integrated mobility management scheme that advantageously combines the mobility management of MAC layer, network layer and application layer is presented. The experimental results show that this integrated model provides fast handover and reduces the packet loss for ongoing media sessions.

An approach of QoS library redirection method for DiffServ in Microsoft Windows systems

The paper presents an implementation of QoS library redirection (QLR) for DiffServ in Microsoft Windows systems. In the QLR method, the legacy application obtains packet pre-marking ability without any modification of source codes. We have upgraded the FTP and vic (video conferencing) applications by using QLR in our Microsoft Windows testing platform. Our experimental results show that this approach can use really effectively and provide high performance of the QLR in Microsoft Windows systems.