• International Journal of Control, Automation, and Systems
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• v.5 no.3
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• pp.317-323
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• 2007

Quality of Service (QoS) in the Internet depends on queuing and sophisticated scheduling in routers. In this paper, we address the issue of managing traffic flows with different priorities. In our reference model, incoming packets are first classified based on their priority, placed into different queues with different capacities, and then multiplexed onto one router link. The fuzzy nature of the information on Internet traffic makes this problem particularly suited to fuzzy methodologies. We propose a new solution that employs a fuzzy inference system to dynamically and efficiently schedule these priority queues. The fuzzy rules are derived to minimize the selected Lyapunov function. Simulation experiments show that the proposed fuzzy scheduling algorithm outperforms the popular Weighted Round Robin (WRR) queue scheduling mechanism.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.5
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• pp.959-975
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• 2011

Wireless mesh networks enlarge the wireless coverage area by interconnecting relatively stationary wireless routers (mesh routers). As wireless mesh networks are envisioned to provide high-bandwidth broadband Internet service to a large community of users, the Internet gateway, which acts as a central point of Internet attachment for the mesh networks, is likely to suffer heavily from the scramble for shared wireless resources because of aggregated traffic toward the Internet. It causes performance decrement on end-to-end transmissions. We propose a scheme to balance the load in a mesh network based on link quality variation to different Internet gateways. Moreover, under the mesh coverage, mobile nodes can move around and connect to nearby mesh routers while still keeping the connections to the Internet through the best gateway in terms of link quality. In this structure, gateways perform the balancing procedure through wired links. Information about gateways and mobile node's location is distributed appropriately so that every mesh router can quickly recognize the best gateway as well as the positions of mobile nodes. This distributed information assists mobile nodes to perform fast handoff. Significant benefits are shown by the performance analysis.

• Journal of KIISE
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• v.43 no.1
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• pp.1-12
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• 2016

As the need for a flexible Internet grows, research for software and virtual routers has increased. Although software routers and virtual routers provide Internet flexibility, they have low performance compared with existing hardware routers. In addition, the low performance problem is intensified in virtual routers because they have virtualization overheads. GPU routing is one method of improving the performance of software routers. However, previous GPU routing is based on native software routers, which are not virtualized, and presents experimental simulation results only. In this paper, we examine the effect of GPU routing on a virtual router using PathSavanna. Our GPU routing is implemented on the virtual router and forwards real packets to another machine, which is connected by a network.

• Journal of Communications and Networks
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• v.18 no.6
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• pp.948-961
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• 2016

Internet protocol (IP) spoofing is a serious problem on the Internet. It is an attractive technique for adversaries who wish to amplify their network attacks and retain anonymity. Many approaches have been proposed to prevent IP spoofing attacks; however, they do not address a significant deployment issue, i.e., filtering inefficiency caused by a lack of deployment incentives for adopters. To defeat attacks effectively, one mechanism must be widely deployed on the network; however, the majority of the anti-spoofing mechanisms are unsuitable to solve the deployment issue by themselves. Each mechanism can work separately; however, their defensive power is considerably weak when insufficiently deployed. If we coordinate partially deployed mechanisms such that they work together, they demonstrate considerably superior performance by creating a synergy effect that overcomes their limited deployment. Therefore, we propose a universal anti-spoofing (UAS) mechanism that incorporates existing mechanisms to thwart IP spoofing attacks. In the proposed mechanism, intermediate routers utilize any existing anti-spoofing mechanism that can ascertain if a packet is spoofed and records this decision in the packet header. The edge routers of a victim network can estimate the forgery of a packet based on this information sent by the upstream routers. The results of experiments conducted with real Internet topologies indicate that UAS reduces false alarms up to 84.5% compared to the case where each mechanism operates individually.

• Journal of Computing Science and Engineering
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• v.1 no.1
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• pp.31-55
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• 2007

Contemporary end-servers and network-routers rely on traffic shaping to deal with server overload and network congestion. Although such traffic shaping provides a means to mitigate the effects of server overload and network congestion, the lack of cooperation between end-servers and network-routers results in waste of network resources. To remedy this problem, we design, implement, and evaluate NetDraino, a novel mechanism that extends the existing queue-management schemes at routers to exploit the link congestion information at downstream end-servers. Specifically, NetDraino distributes the servers' traffic-shaping rules to the congested routers. The routers can then selectively discard those packets-as early as possible-that overloaded downstream servers will eventually drop, thus saving network resources for forwarding in-transit packets destined for non-overloaded servers. The functionality necessary for servers to distribute these filtering rules to routers is implemented within the Linux iptables and iproute2 architectures. Both of our simulation and experimentation results show that NetDraino significantly improves the overall network throughput with minimal overhead.

• Journal of KIISE:Information Networking
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• v.29 no.5
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• pp.510-523
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• 2002

The routers in an active network perform customized computations on the messages flowing through them, while the role of routers in the traditional packet network, such as the Internet, is to passively forward packets as fast as possible. In contrast to the Internet, the processing in active networks can be customized on a per user or per application basis. Active networks allow users to inject information into the network, where the information describes or controls a program to be executed for the users by the routers as well as the end hosts. So the network users can realize the active networks by "programming" the network behavior via the programming interface exposed to them. In this paper, we devise a network protocol model and present a verification technique for reasoning about the correctness of an active application defined using the model. The technique is developed in a platform- and language-independent way, and it is algorithmic and can be automated by computer program. We give an example dealing with network auction to illustrate the use of the model and the verification technique.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.27-38
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• 2019

Sensors collect information for Internet of Things (IoT)-based services. However, indoor construction sites have a poor communication environment and many interfering elements that make it difficult to collect sensor information. In this study, a network was constructed between a Bluetooth Low Energy (BLE)-based IoT device based on a serverless IoT framework and a router. This experimental environment was applied to large- and small-scale indoor construction sites. Experiments were performed to test the communication performance of BLE-based IoT devices and routers at indoor construction sites. An analysis of the received signal strength indication (RSSI) graph patterns collected from the communication between the BLE-based IoT devices and routers for different testbed site situation revealed areas with good communication performance and poor communication performance due to interfering factors. The results confirmed that structural components of the building as well as the materials, equipment, and temporary facilities used in indoor construction interfere with the communication performance. Construction project managers will require improved technical knowledge of IoT, such as optimizing the router placement and matching communication between the router and workers, to improve the communication performance for large-scale indoor construction.

• Journal of KIISE:Information Networking
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• v.32 no.6
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• pp.745-752
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• 2005

BGP is a unique routing protocol in broadband internet. It chooses routing paths considering internet hierarchy and local policies. As BGP routers selectively bypass routing information to a subset of neighboring BGP routers, connectivity by way of a series of links between source and destination nodes does not mean reachability of routing information of the two. In emergency when BGP routers or links over wide range are not available, BGP routers have to use links that are not normally used to keep reachability. This paper listed out the requirements for BGP backup routing and proposed a routing solution that hides most demerits in currently published ones. The proposed backup operates in three tiers according to network damage. Under this rule, BGP routers use tier-0 routing paths at normal. If networks are impaired, they choose tier-1 paths. If networks are seriously damaged, tier-2 paths are allowed to use. Also this paper proves that the proposed backup guarantees stability and safeness. As results, the proposed backup is very adaptive to light network damages as well as serious ones and provides strong routing reachability at all times.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.9
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• pp.4641-4657
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• 2017

Named Data Networking (NDN) has emerged and become one of the most promising architectures for future Internet. However, like traditional IP-based networking paradigm, NDN may not evade some typical network threats such as malicious data aggregates (MDA), which may lead to bandwidth exhaustion, traffic congestion and router overload. This paper firstly analyzes the damage effect of MDA using realistic simulations in large-scale network topology, showing that it is not just theoretical, and then designs a fine-grained MDA mitigation mechanism (MDAM) based on the cooperation between routers via alert messages. Simulations results show that MDAM can significantly reduce the Pending Interest Table overload in involved routers, and bring in normal data-returning rate and data-retrieval delay.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.11C
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• pp.1171-1177
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• 2002

In this paper, we proposed a high speed IP(Internet Protocol) packet forwarding engine of ATM(Asynchronous Transfer Mode) based label edge routers for POS(Packet over SONET) interface. The forwarding engine uses TCAM(Ternary Content Addressable Memory) for high performance lookup processing of the packet received from POS interface. We have accomplished high speed IP packet forwarding in hardware by implementing the functions of high speed IP header Processing and lookup control into FPGA(Field Programmable Gate Array). The proposed forwarding engine has the functions of label edge routers as the lookup controller supports MPLS(Multiprotocol Label Switching) packet processing functionality.