Computer Science

The network partition problem in switched industrial Ethernet is analyzed, which is shown to be equivalent to a multi-objective optimization problem: the network partition should reduce the inter-network communication, and simultaneously make the network traffic be evenly distributed over the respective sub-networks. Furthermore, the switch capability must be respected when assigning devices to sub-networks, which sets constraints for the optimization

IP Multicast is an important enabling service for the current and future Internet. With the explosive, growth of the Internet, a challenging issue facing IP multicast is scalability, in particular, the problem of multicast forwarding state and control explosion. In this paper, we propose a new methodology to address the multicast scalability problem for backbone domains Multicast Tunneling with Branch Filtering (MTBF). This multicast group aggregation scheme is designed on top of the inter-domain protocol architecture such as MASC/BGMP, and is independent of any underlying intra-domain multicast protocols. It aggregates multicast groups by constructing Border Router (BR)-based multicast routing trees and forwards data by using an encapsulation technique called Multicast Tunneling (MT). To minimize excess traffic due to aggregate multicast address based data forwarding, an efficient Dynamic Filtering Point Selection (DFPS) algorithm is used. The feasibility and performance of our scheme is demonstrated through analysis and simulations

For mission-critical network systems such as distributed process control applications, it is essential that the underlying networking system provides end-to-end deadline guarantees. Since network resources such as switches are shared among the hosts, it is more likely to have a ...

We propose Adaptive Geo-Source Multicast Routing (AGSMR) for WSNs. It addresses the scalability issue of previous location based stateless multicast protocols in WSNs. AGSMR is a novel stateless multicast protocol that optimizes the location-based and source-based multicast approaches in various ways. First, it saves the cost of a tree building by using receiver’s geographic location information during the receiver’s the membership establishment stage without flooding. Second, it decreases computation time, in turn, energy usage by determining the multicast routing path at a multicast source node (or rendezvous point (RP)) rather than calculating and selecting neighbors at each forwarding node. Third, it reduces packet overhead by encoding with a small node ID instead of potentially large location information, and by adaptively using branch geographic information for common source routing path segments.

Traffic measurement and monitoring are an important component of network management and traffic engineering. With high-speed Internet backbone links, efficient and effective packet sampling techniques for traffic measurement and monitoring are not only desirable, but also increasingly becoming a necessity. Since the utility of sampling depends on the accuracy and economy of measurement, it is important to control sampling error. In this paper, we propose an adaptive packet sampling technique for flow-level traffic measurement with a stratification approach. We employ and advance sampling theory in order to ensure the accurate estimation of large flows. With real network traces, we demonstrate that the proposed sampling technique provides unbiased estimation of flow size with controllable error bound, in terms of both packet and byte counts for elephant flows, while avoiding excessive oversampling.

IP Multicast is an important enabling service for the current and future Internet. With the explosive, growth of the Internet, a challenging issue facing IP multicast is scalability, in particular, the problem of multicast forwarding state and control explosion. In this paper, we propose a new methodology to address the multicast scalability problem for backbone domains Multicast Tunneling with Branch Filtering (MTBF). This multicast group aggregation scheme is designed on top of the inter-domain protocol architecture such as MASC/BGMP, and is independent of any underlying intra-domain multicast protocols. It aggregates multicast groups by constructing Border Router (BR)-based multicast routing trees and forwards data by using an encapsulation technique called Multicast Tunneling (MT). To minimize excess traffic due to aggregate multicast address based data forwarding, an efficient Dynamic Filtering Point Selection (DFPS) algorithm is used. The feasibility and performance of our scheme is demonstrated through analysis and simulations

Traffic measurement and monitoring is an important component of network QoS management and traffic engineering. With high-speed Internet links, efficient and effective packet sampling techniques for traffic measurement are not only desirable, but increasingly becoming a necessity. In this paper, we propose and analyze an adaptive random packet sampling technique for traffic load measurement. In particular, we address the problem of bounding sampling error within a pre-specified tolerance level. Using real network traffic traces, we show that the proposed adaptive random sampling technique indeed produces the desired accuracy, while also yielding significant reduction in the amount of traffic samples.

For mission-critical network systems such as distributed process control applications, it is essential that the underlying networking system provides end-to-end deadline guarantees. Since network resources such as switches are shared among the hosts, it is more likely to have a ...

We propose Adaptive Geo-Source Multicast Routing (AGSMR) for WSNs. It addresses the scalability issue of previous location based stateless multicast protocols in WSNs. AGSMR is a novel stateless multicast protocol that optimizes the location-based and source-based multicast approaches in various ways. First, it saves the cost of a tree building by using receiver’s geographic location information during the receiver’s the membership establishment stage without flooding. Second, it decreases computation time, in turn, energy usage by determining the multicast routing path at a multicast source node (or rendezvous point (RP)) rather than calculating and selecting neighbors at each forwarding node. Third, it reduces packet overhead by encoding with a small node ID instead of potentially large location information, and by adaptively using branch geographic information for common source routing path segments.

Point-to-point delay is an important network performance measure as it captures service degradations caused by various events. We study how to measure and report delay in a concise and meaningful way for an ISP, and how to monitor it efficiently. We analyze various measurement ...

We propose a network quality aware routing (NQAR) mechanism to provide an enabling method of the delay-sensitive data delivery over error-prone wireless sensor networks. Unlike the existing routing methods that select routes with the shortest arrival latency or the minimum hop count, the proposed scheme adaptively selects the route based on the network qualities including link errors and collisions with minimum additional complexity. It is designed to avoid the paths with potential noise and collision that may cause many non-deterministic backoffs and retransmissions. We propose a generic framework to select a minimum cost route that takes the packet loss rate and collision history into account. NQAR uses a data centric approach to estimate a single-hop delay based on processing time, propagation delay, packet loss rate, number of backoffs, and the retransmission timeout between two neighboring nodes. This enables a source node to choose the shortest expected end-to-end delay path to send a delay-sensitive data. The experiment results show that NQAR reduces the end-to-end transfer delay up to approximately 50% in comparison with the latency-based directed diffusion and the hop count-based directed diffusion under the error-prone network environments. Moreover, NQAR performs better than other routing methods in terms of jitter, reachability, and network lifetime.