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Along with the popularization and adoption of IP in various emerging scenarios, challenges also arise with the ossified address structures. The reason is that conventional IP address is designed with fixed length and lacking extensibility, while the demand for IP varies greatly in different scenarios. Flexible IP (FlexIP), as a variable-length IP address, proactively makes address structure flexible enough to adapt to various network cases and solves the problem of low transmission efficiency faced by current IP addresses. However, due to the variable length of FlexIP, the conventional routing addressing scheme is not suitable for it. In this paper, we propose a new Bloom filter addressing scheme suitable for FlexIP address. We use controllable prefix extension to limit the prefix distribution of FlexIP, and use one-hashing to improve the computational overhead of the Bloom filter. Simulations show that the addressing scheme we proposed is more suitable for FlexIP than other schemes, and has better query efficiency.

Wireless sensor networks have been widely used in environmental monitoring, but one of the characteristics of the traditional IPv6 wireless sensor networks using in the environmental monitoring is traffic convergent. In the root node, the flow of collecting sensor data could be much heavy than other nodes. The overall structure of the load is unbalance. Therefore, using multiple devices at the root node deployment to facilitate data collection could be inevitable in heavy traffic sensor environment. However, with the increase of the number of sensor nodes deployed at the root nodes, it is hard to control the access between them. In this paper, an IPv6-based load balancing strategy for ecological monitoring network are presented to solve this problem. Finally, we will use some experiments to prove its effectiveness.

6LoWPAN is the short name for the IPv6 low-power wireless personal area network. Traditional 6LoWPAN use RPL routing protocols. When the RPL protocol is in storage mode, each node needs to keep the routing information of all the nodes in the subtree. When the network size is large, the number of the node's routing table entry will be very large. This paper presents a hierarchical cluster routing protocol (HCRP). This is a switch-based routing protocol, different from the traditional routing protocol. It contains the routing path information in the node's IP address. It can solve the above problems. Each node stores only its parent node information and a small amount of configuration information. Finally, it is proved that the HCPR is superior to the traditional RPL protocol in many aspects.

In the application layer multicast (ALM), providing reliable (i.e., lossless) data delivery service is complex. This paper proposes a hierarchical loss recovery solution, called HR, for reliable application layer multicast. HR can be used as an extension to existing tree-based ALM protocols, to provide lossless ALM service. In the HR solution, the group members at the top of the ALM tree are in a recovery plane (i.e., Plane 1), and the members at the bottom of the ALM tree are in another recovery plane (i.e., Plane 2). HR employs a robust and quick approach to recover the losses at the group members in Plane 1, which can avoid the potential losses at the downstream nodes and provide many relatively reliable recovery sources. HR uses a loss recovery approach, which can effectively reduce the link load, to recover the loss found by the group member in Plane 2. In HR, the recovery packet is retransmitted by an area-constrained multicast means, which can recover the loss at one or multiple group members with little recovery diffusion. Through a cooperative and active way, HR can effectively address the error correlation problem of ALM.

This paper presents a two-tiered reliable application layer multicast (ALM) solution, called HRALM, to provide lossless ALM services. HRALM builds a domain-based multicast tree, and divides the members into two transport planes (i.e., Plane 1 and Plane 2) in terms of the tree. In any domain, the distance between each member and the domain header is below a given threshold, which improves the capability of topology-awareness. According to the loss detected by members in different planes, HRALM adopts different but correlated recovery solutions. In HRALM, a member duplicates and forwards the received recovery packet to each of its children if it has not received the data unit carried by the recovery packet before receiving the recovery packet, which can actively recover the loss at the downstream nodes. The simulation experiments show that HRALM has desirable transport and recovery performance.

The Heihe Watershed Allied Telemetry Experimental Research (HiWATER) is a significant research project that performs airborne, satellite-borne and ground based remote sensing experiments at various scales by coordinating interdisciplinary researchers from different institutions and projects. Therefore, in order to discover, access and process sensors within the heterogeneous systems, we use the Sensor Model Language (Sensor ML) to model these sensors and sensor systems in the stations, and use Sensor Observation Service (SOS) to display the sensor information and observation data information. In this paper, we firstly introduce the Sensor ML and SOS, then mainly present a model of sensor station and the application of this model in SOS.

Environmental monitoring in ecological and hydrological watershed-scale research is an important and promising area of application for wireless sensor networks. This paper presents the system design of the IPv6 wireless sensor network (IPv6WSN) in the Heihe River watershed in the Gansu province of China to assist ecological and hydrological scientists collecting field scientific data in an extremely harsh environment. To solve the challenging problems they face, this paper focuses on the key technologies adopted in our project, metadata modeling for the IPv6WSN. The system design introduced in this paper provides a solid foundation for effective use of a self-developed IPv6 wireless sensor network by ecological and hydrological scientists.

We develop a remote monitoring system on environmental quality of Heihe river basin. The system consists of client and server, client is responsible for collecting data. We use multi-thread approach to develop server software, realizing online monitoring of sensor device, data management and log management and so on. Server uses Socket programming to communicate with client, the system has been running on the server.

In application layer multicast (ALM), member hosts lack direct knowledge of underlying network topology, which brings some performance penalty. This paper investigates an effective way to rapidly obtain some related topology knowledge, i.e. getting topology hints from existing IP registered resources -- WHOIS database. We further propose a clustering scheme, which can be integrated into the existing ALM solutions. Our proposed scheme can cluster some nearby member hosts no matter when these hosts join the group. Therefore the scheme also solves the join sequences problem in some degree. We also present an application framework of the clustering scheme, and give an application example named HMTP-E that integrates the scheme into HMTP protocol. The experiment results show that the clustering scheme plays a positive role on improving the performance of existing ALM solutions.

Environmental monitoring in ecological and hydrological watershed-scale research is an important and promising area of application for wireless sensor networks. This paper presents a system design of IPv6 wireless sensor network (IPv6WSN) in Heihe river watershed in Gansu province of China to assist ecological and hydrological scientists collecting field scientific data in an extremely harsh environment. To solve the challenging problems, this paper focus on three key technologies adopted in our project, which includes the design of hardware platform, integration of the newest network protocol (IPv6), Metadata modeling for IPv6WSN. The system design introduced in this paper provides a solid foundation for effective use of self-developed IPv6 wireless sensor network by ecological and hydrological scientists.

The converge cast traffic pattern ???many-to-one data communication??? of wireless sensor networks leads to high load at nodes that are aggregating data. Therefore, we need to distribute the entire traffic load by deploying multiple data collectors and each node should select a collector node to access. Additionally, with the progress of IPv6-based wireless sensor networks, advantages of IPv6 protocols can be considered to address the above problem. In this paper, we propose an IPv6-based traffic balancing scheme for multiple mobile data collectors in wireless sensor networks, which can distribute the traffic load on multiple mobile data collectors based on IPv6 any cast and pseudo-mobility (IPv6APM). The scheme has the advantages of seamless compatibility with current protocol, higher scalability, short delay time, no topological constraint compared to other approaches. We also present our simulation work and discuss performance comparison between the scheme and other load balancing mechanisms. The results show that the scheme has very advanced performance and scalability.

Identity management and secure end to end communication are the core topics of trustworthy network research. This paper proposes a hierarchical IPv6 real-name address space as network identity. We also built an IPv6 real-name address resource PKI according to current IP address allocation structure for real-name address allocation, management and authentication work. We designed and implemented a trustworthy communication system supported by third party's IPv6 real-name address resource PKI. This method can overcome the inherent defects of IPsec that may be circumvented in the identifier conversion process and mobile environment. It also provides end to end authentication service on the Internet. We believe this is an effective solution for Internet real-name access and privacy protection problem.

Teredo is a service that enables nodes located behind one or more IPv4 Network Address Translations (NATs) to obtain IPv6 connectivity by tunneling packets over IPv4 UDP. Although Teredo is a useful protocol, it also has some weaknesses. It can not work with symmetric NAT, and it raises some security concerns, such as bypassing security controls, reducing defense in depth, and allowing unsolicited traffic. In this paper, we propose a new IPv6-in-IPv4-UDP tunneling protocol—Escort, which adopts ID/Locator split thought, and we explain how an Escort client configures its Escort host identity address, learns its global Escort IPv6 address and obtains IPv6 connectivity with the help of Escort servers and Escort relays. We also describe in details our strategies for implementing Escort server and Escort relay under linux, and make a performance measurement of our Escort relay implementation and compare the packet processing latency of the Escort relay with that of Miredo-relay.

An efficient fault diagnosis is very helpful to save the time and resource of revising the found faults in the protocol conformance test procedure. However, it is very difficult to diagnose transfer faults accurately and quickly. This paper proposes a test precondition (called input-correct precondition) which is satisfied through the local test in the system development procedure. We further presents a transfer fault diagnosing method based on the finite state machine (FSM), which is applied to diagnose the possible transfer faults in an implementation that satisfies the input-correct precondition. The diagnosing method attempts to provide desirable transfer fault hints or locate some transfer faults accurately in terms of the protocol conformance test results.

The domain name system (DNS) is one of the most basic Internet infrastructures. Therefore, the IPv6 conformance testing is very necessary for accelerating the deployment of IPv6. This paper proposes a conformance testing framework for IPv6 DNS, in terms of the features of IPv6 DNS specifications. This framework employs the extended finite state machine (EFSM) model to describe the control and data flows of dynamic behaviors of IPv6 DNS, and configures the relevant variables and data files by a configuration module which can reduce the test cost.

In the group application, poor multicast trees might be built in some join sequences. Additionally, group members are dynamic, which sometimes brings negative influence on the multicast tree. This paper analyzes the poor shapes of multicast trees, and proposes an additional improvement scheme to enhance the multicast performance. The proposed scheme rearranges the locations of members in terms of a distance-heuristics, which makes the improved multicast tree be coincident with the underlying network topology in some degree. The simulation results show that our proposed improvement scheme can effectively enhance the multicast performance.

IPv6 is a new version protocol for next generation Internet, which has the advantages of supporting scalability, mobility and security better than current IPv4 Internet. However, IPv4 and IPv6 are not directly compatible. IPv4/IPv6 translator with high performance and reliability can facilitate the seamless coexistence of IPv4 and IPv6 networks during the transition period. In this paper, we proposed a design and implementation of IPv4/IPv6 translator using network processors. The challenges of this work lie in three areas: (1) effective use of network processor resources, (2) design and implementation of an advanced control plane on a commodity OS, and (3) fault tolerance to improve reliability of the whole system. We discuss our solutions to these challenges and presented analytic models to investigate the fault tolerance issue of our approaches. Our work provided guidelines and insights into design, implementation and configuration of the IPv4/IPv6 translator.

There are a number of works trying to adjust the contention window (CW) in order to provide differentiated service in IEEE 802.11-based wireless networks. However, these protocols cannot deliver firm service guarantees while maintaining high network utilization, particularly under congested network conditions. In this paper, we propose an adaptive enhanced service differentiation mechanism for QoS provisioning in IEEE 802.11e wireless networks. The mechanism includes traffic conditioning and adaptive MID CW updating rule with service differentiation based on per queue. Relative priorities are provisioned by adjusting the size of the CW of each traffic class taking into account both applications requirements and network conditions. Simulation results show that the proposed mechanism outperforms the basic EDCA scheme of 802.11e and another proposed scheme AEDCF in terms of network utilization, goodput and delay.

We proposed a new load balancing mechanism, called LBAM (load balancing based on pseudo-anycast and pseudo-mobility in IPv6), by which sessions can be distributed across a pool of servers for maximum performance. Load balancing is needed in many fields, such as Web servers, FTP server and NAT gateway, and there exist several approaches for load balancing. However, current approaches have problems such as poor scalability, inability to balance session flow, long latency time, and topological constraint on server pools. In this paper, we describe how LBAM works in principle without the above problems. We also present our simulation work using NS-2 and discuss performance comparison between LBAM and other load balancing mechanisms. The results show that LBAM has a very advanced performance and scalability. Finally, the ubiquitous applications of LBAM in NGI (next generation Internet) are presented.

Most of the existing congestion control works are suitable for the best effort flows, but not for the flows with quality of service (QoS) requirements. In this paper, by adopting equation-based congestion control (EBRC) for differentiated services instead of traditional TCP congestion control for best-effort service, a new congestion control mechanism supporting QoS requirements can be achieved. Three parts which the mechanism consists of are sender functionality, packet loss control mechanism in routers and receiver functionality. The details of design and implementation within this mechanism are investigated.

In the protocol conformance testing, many existing test methods can effectively detect the possible faults of the implementation under test. However, it is difficult to diagnose the found faults in terms of the test results. This paper presents a diagnosable input/output (DIO) sequence, to differentiate a state from other states under a given condition. We further propose a two-tier protocol conformance testing and diagnosing method based on DIO sequences. The proposed method can effectively detect and diagnose the possible faults of the implementation of a protocol.