Traffic Off Research Articles

Analyzing Network Time Protocol (NTP) Based Amplification DDoS Attack and its Mitigation Techniques

Network Time Protocol amplification attack is a form of distributed denial-of-service (DDoS) attack in which an attacker exploits or sends a request to a vulnerable NTP server by using their IP address to flood a targeted network or server with an overwhelming volume of User Datagram Protocol (UDP) traffic. In the past, the techniques that involved reflecting traffic off NTP servers to the victim, with the attacker hiding their identity by spoofing the source IP address were carried out using mainly Domain Name Server (DNS) servers but the use of vulnerable NTP servers as reflectors in DDoS attacks has gain lot of popularity since 2014, and this is as a result of the realization of high amplification scale that NTP servers can provide. This type of reflector attack maximized the use of the amplification factor of NTP servers to magnify the attack bandwidth, making it particularly disruptive and difficult to mitigate. Since NTP amplification is not a popularly known attack and there has not been much thorough research on it, this paper explores a holistic overview of NTP amplification attacks, how NTP is used for DDoS attacks, and the overall method that can be used to mitigate such attacks. Keywords: Distributed Denial-of-Service (DDoS) attack, DNS servers, NTP servers

Analyzing Network Time Protocol (NTP) Based Amplification DDoS Attack and its Mitigation Techniques

Network Time Protocol amplification attack is a form of distributed denial-of-service (DDoS) attack in which an attacker exploits or sends a request to a vulnerable NTP server by using their IP address to flood a targeted network or server with an overwhelming volume of User Datagram Protocol (UDP) traffic. In the past, the techniques that involved reflecting traffic off NTP servers to the victim, with the attacker hiding their identity by spoofing the source IP address were carried out using mainly Domain Name Server (DNS) servers but the use of vulnerable NTP servers as reflectors in DDoS attacks has gain lot of popularity since 2014, and this is as a result of the realization of high amplification scale that NTP servers can provide. This type of reflector attack maximized the use of the amplification factor of NTP servers to magnify the attack bandwidth, making it particularly disruptive and difficult to mitigate. Since NTP amplification is not a popularly known attack and there has not been much thorough research on it, this paper explores a holistic overview of NTP amplification attacks, how NTP is used for DDoS attacks, and the overall method that can be used to mitigate such attacks. Keywords: Distributed Denial-of-Service (DDoS) attack, DNS servers, NTP servers

Energy and Latency Efficient Caching in Mobile Edge Networks: Survey, Solutions, and Challenges

Future wireless networks provide research challenges with many fold increase of smart devices and the exponential growth in mobile data traffic. The advent of highly computational and real-time applications cause huge expansion in traffic volume. The emerging need to bring data closer to users and minimizing the traffic off the macrocell base station introduces the use of caches at the edge of the networks. Storing most popular files at the edge of mobile edge networks (MENs) in user terminals (UTs) and small base stations caches is a promising approach to the challenges that face data-rich wireless networks. Caching at the mobile UT allows to obtain requested contents directly from its nearby UTs caches through the device-to-device (D2D) communication. In this survey article, solutions for mobile edge computing and caching challenges in terms of energy and latency are presented. Caching in MENs and comparisons between different caching techniques in MENs are presented. An illustration of the research in cache development for wireless networks that apply intelligent and learning techniques in a specific domain in their design is presented. We summarize the challenges that face the design of caching system in MENs. Finally, some future research directions are discussed for the development of cache placement and cache access and delivery in MENs.

Ship collision avoidance behaviour recognition and analysis based on AIS data

A novel approach is proposed to automatically identify the ship collision avoidance behaviour from ship trajectories based on an improved Sliding Window Algorithm. The approach has three main stages: (1) determining the ships’ obligations according to the Convention on the International Regulations for Preventing Collision at Sea (COLREGs); (2) assessing the rudder angle according to the true bearing of the target ship; (3) identifying the corresponding ship handling behaviour from the ship trajectory taking into account the Rate of Turn and its derivative based on the Sliding Window Algorithm. Four typical encounter scenarios are studied to demonstrate the feasibility and effectiveness of the proposed method. The approach is then applied to near collision scenarios identified in the maritime traffic off the continental coast of Portugal, which allowed the characterization of the relative and spatial distributions of the locations at which the ships take evasive manoeuvres. The results show that the approach can be applied to accurately detect the ship collision avoidance behaviour from Automatic Identification System trajectory data, and the characterization of the collision avoidance behaviour can potentially be used by situational awareness systems and as the basis for ship collision avoidance decision-making.

Defining priority areas for blue whale conservation and investigating overlap with vessel traffic in Chilean Patagonia, using a fast-fitting movement model

Defining priority areas and risk evaluation is of utmost relevance for endangered species` conservation. For the blue whale (Balaenoptera musculus), we aim to assess environmental habitat selection drivers, priority areas for conservation and overlap with vessel traffic off northern Chilean Patagonia (NCP). For this, we implemented a single-step continuous-time correlated-random-walk model which accommodates observational error and movement parameters variation in relation to oceanographic variables. Spatially explicit predictions of whales’ behavioral responses were combined with density predictions from previous species distribution models (SDM) and vessel tracking data to estimate the relative probability of vessels encountering whales and identifying areas where interaction is likely to occur. These estimations were conducted independently for the aquaculture, transport, artisanal fishery, and industrial fishery fleets operating in NCP. Blue whale movement patterns strongly agreed with SDM results, reinforcing our knowledge regarding oceanographic habitat selection drivers. By combining movement and density modeling approaches we provide a stronger support for purported priority areas for blue whale conservation and how they overlap with the main vessel traffic corridor in the NCP. The aquaculture fleet was one order of magnitude larger than any other fleet, indicating it could play a decisive role in modulating potential negative vessel-whale interactions within NCP.

Spatial correlation analysis of near ship collision hotspots with local maritime traffic characteristics

A spatial correlation analysis of near collision clusters with local traffic characteristics is presented. The Moran's I and Getis-Ord Gi* spatial autocorrelation methods are used to determine whether near collisions show spatial clustering from global and local perspectives. The application of the developed approach to Automatic Identification System data of the maritime traffic off the coast of Portugal shows that there are several hotspots where the density of ship near collisions is relatively high. A co-occurrence analysis is then conducted to relate the near collision hotspots with selected local maritime traffic characteristics such as the average ship speed, speed dispersion, degree of speed acceleration, ship route overlaps and degree of angular deviation from ship route centreline. The identification of near collisions clusters and the assessment of the correlation of ship near collision hotspots with the maritime traffic features provide a means for improving maritime safety and reducing the occurrence of ship-ship collisions.

Illegal Under the Laws of All Nations? The Courts of Haiti and the Suppression of the Atlantic Trade in African Captives

In 1816, the mostly-American crew of a slaving brig bound from Cuba staged a mutiny before reaching West Africa, and then sailed on (without a captive cargo) to the antislavery republic of Haiti. Their voyage culminated in a remarkable prize case before the admiralty court at Port-au-Prince. The sailors claimed indignation at the “diabolical” slave trade, hoping to win profits from the condemnation of the vessel and to avoid future prosecution for enlisting in a slaving voyage that was illegal under U.S. federal law. Haitian prosecutors invoked the agreements of the Congress of Vienna, arguing that the trade had been prohibited by the laws of nations. It fell to the admiralty court to reconcile such aspirational claims with Haiti's ongoing struggle for political survival. The brig's journey between the United States, Cuba, Spanish Florida, Cape Verde, and finally Haiti reveals the ways in which slave traders calculated the relative risks of legal penalties against the possible gains from the trade. The records of the adjudication of the case show how Haitian officials developed their own legal strategies for the suppression of the trade, laying the foundations for an escalating campaign to police slaving traffic off of their shores.

Vector field observations near the continental slope off Big Sur, California

In this work, data collected approximately 3 km off the coast of Big Sur, California, by a low frequency vector sensor system will be analyzed. Directional and temporal variations in the ambient noise field will be evaluated, and causes will be considered including flow noise due to currents, surface (wind) noise, distant shipping, and marine mammals. Bearing estimation results for shipping will be compared with AIS tracks recorded during the period of deployment. Local sound speed measurements and bathymetry in the vicinity of the deployment area will be used as inputs to a two-dimensional propagation model that properly invokes reciprocity of the acoustic vector field. Surface wave spectra collected by a nearby buoy will be used to generate rough surface realizations in order to evaluate the impact of these perturbations on low frequency vector field structure. These results will be combined with acoustic data observations in attempts to determine the impact of propagation on the structure of the field. Such an approach may allow us to infer acoustic source levels of AIS traffic off the coast.

Mobility as an Alternative Communication Channel: A Survey

We review the research literature investigating systems in which mobile entities can carry data while they move. These entities can be either mobile by nature (e.g., human beings and animals) or mobile by design (e.g., trains, airplanes, and cars). The movements of such entities equipped with storage capabilities create a communication channel which can help overcome the limitations or the lack of conventional data networks. Common limitations include the mismatch between the capacity offered by these networks and the traffic demand or their limited deployment owing to environmental factors. Application scenarios include offloading traffic off legacy networks for capacity improvement, bridging connectivity gaps, or deploying ad hoc networks in challenging environments for coverage enhancement.

Understanding Livable Streets in the Context of the Arterials that Surround Them

Not long after the advent of cars, a conflict between traffic and residential livability arose. The typical response pushed traffic off residential streets and onto nearby major roads. This line of thinking evolved into a hierarchical approach to the street networks and arterial roads designed to carry the majority of vehicle traffic. With many researchers identifying traffic on residential streets to be an underlying issue behind poor livability, this solution makes sense. However, is the relationship between residential livability and traffic moderated by the character of the nearby arterial road? By use of a residential study in Denver, Colorado, 10 arterials were partitioned along two dimensions: high and low traffic and high and low design quality. Comparable residential roads within the surrounding neighborhoods were selected to fit descriptions of heavy, moderate, and light traffic, and 723 residents were surveyed. The results suggest that the surrounding street network—in particular, the character of the nearby arterial road—influences the livability of residential areas on the adjacent streets according to a number of livability measures. When income was controlled for, both high levels of traffic and low levels of urban design on the arterial were found to detract from livability in the surrounding neighborhoods, sometimes more so than the residential street traffic itself. This finding should not be taken as a call to shift traffic onto residential streets. Rather, planners and engineers need to take a broader perspective and consider the whole network to understand livability. Livable residential streets can be only part of the solution; more livable arterials are also needed.

Spatial and Temporal Variability in Shipping Traffic Off San Francisco, California

Shipping traffic poses a worldwide threat to many large whale species. Spatially explicit risk assessments are increasingly being used as a tool to minimize ship-strike risk. These assessments often use static representations of shipping patterns. We used Automatic Identification System data to quantify variability in cargo shipping traffic entering and exiting San Francisco Bay, which contains some of the busiest ports in the United States, at three temporal resolutions: (1) before and after implementation of the California Air Resources Board's Ocean-Going Vessels Fuel Rule, (2) among seasons, and (3) day versus night. We used the nonparametric Mood's Median test to compare median daily distance traveled because the data were not normally distributed and the variance was not homogeneous. Our analyses show that shipping traffic off San Francisco is dynamic at both interannual and daily temporal resolutions, but that traffic was fairly consistent among the seasons considered. Our analyses emphasize the importance of economic and regulatory drivers on interannual shipping traffic patterns. Shipping traffic is expected to continue to change off the U.S. West Coast and to increase globally. These changes in shipping traffic could have implications for the risk of ships striking whales and should be included in risk assessments.

Traffic load-based LPI control mechanism in ethernet access network

IEEE802.3az working group has recommended LPI based Energy Efficient Ethernet standard in order to efficiently reduce unnecessary waste of energy that might occur while there is no data to be transmitted. This paper proposes an enhanced LPI control mechanism to improve energy efficiency between terminal equipment and Ethernet switch in an EEE environment. The proposed mechanism measures the amount of traffic coming to the terminal during specific period of time. According to the measured traffic amount, ON and OFF duration for the following basic cycle will be decided. The performance evaluation results indicate that the suggested mechanism improves the overall performance in a way of significant reduction of energy consumption while it maintains an average packet delay to similar levels compared to the traditional method.

Use of AIS Data to Characterise Marine Traffic Patterns and Ship Collision Risk off the Coast of Portugal

This paper studies the risk of ship collision off the coast of Portugal based on Automatic Identification System (AIS) data, which is recorded and maintained by the Portuguese coastal Vessel Traffic Service (VTS) control centre (CCTMC). Computer programs for decoding, visualization and analysis of the AIS data have been developed. From analysis of the AIS data available, maritime traffic off the coast of Portugal is characterized and a statistical analysis of traffic in the Traffic Separation Schemes is provided. An algorithm has been developed to assess the risk profile and the relative importance of routes associated with ports. A method is proposed to calculate the collision risk from the assessment of the number of collision candidates by estimating future distances between ships based on their previous positions, courses and speeds, and comparing those distances with a defined collision diameter. Values of causation probability suggested in several studies are used to calculate the expected number of collisions in the period of time under investigation based on the number of collision candidates. The results of this study are then compared with the number of collisions that have occurred between 1997–2006, registered and maintained by the Portuguese Maritime Authority.

Assessing the Risk of Ships Striking Large Whales in Marine Spatial Planning

Marine spatial planning provides a comprehensive framework for managing multiple uses of the marine environment and has the potential to minimize environmental impacts and reduce conflicts among users. Spatially explicit assessments of the risks to key marine species from human activities are a requirement of marine spatial planning. We assessed the risk of ships striking humpback (Megaptera novaeangliae), blue (Balaenoptera musculus), and fin (Balaenoptera physalus) whales in alternative shipping routes derived from patterns of shipping traffic off Southern California (U.S.A.). Specifically, we developed whale-habitat models and assumed ship-strike risk for the alternative shipping routes was proportional to the number of whales predicted by the models to occur within each route. This definition of risk assumes all ships travel within a single route. We also calculated risk assuming ships travel via multiple routes. We estimated the potential for conflict between shipping and other uses (military training and fishing) due to overlap with the routes. We also estimated the overlap between shipping routes and protected areas. The route with the lowest risk for humpback whales had the highest risk for fin whales and vice versa. Risk to both species may be ameliorated by creating a new route south of the northern Channel Islands and spreading traffic between this new route and the existing route in the Santa Barbara Channel. Creating a longer route may reduce the overlap between shipping and other uses by concentrating shipping traffic. Blue whales are distributed more evenly across our study area than humpback and fin whales; thus, risk could not be ameliorated by concentrating shipping traffic in any of the routes we considered. Reducing ship-strike risk for blue whales may be necessary because our estimate of the potential number of strikes suggests that they are likely to exceed allowable levels of anthropogenic impacts established under U.S. laws.

Spam and Beyond: An Information-Economic Analysis of Unwanted Commercial Messages

The phenomenon of unwanted commercial messages (UCM), including e-mail spam and emerging forms that target other Internet communications facilities, is analyzed from an information-economics perspective. UCM traffic pays off for its senders when it is noticed and consumed by Internet users; the industry is, therefore, dependent on a common-pool resource that is accessed through an information asset. An analytical model of the industry is derived and solved computationally, and two dimensions of information quality held by the senders of UCM traffic are manipulated in the model. It is shown that such manipulations can moderate over time both the number of UCM campaigns undertaken and the amount of Internet bandwidth consumed by UCM. Manipulations of the information-quality dimensions affected by e-mail filtering reduce the amount of traffic that penetrates an Internet user's attention space but increase the amount of Internet bandwidth consumed. This is consistent with data reported by e-mail security providers as filters have been deployed. It is also shown that both public and private entities have adopted policies and practices with unintentional informational side effects. These effects may have led to more rather than less, spam e-mail traffic. It is concluded that the lessons learned from the case of e-mail spam can be applied to the development of policies and practices for mitigating newer, emerging forms of UCM, including versions targeting instant-messaging systems and Web logs.

Le consulat de France à Larnaca à la fin de la Monarchie de Juillet. Correspondance de D. Fourcade et Th. Goepp (1840-1849). II. L'aide au commerce

Reporting on the state of trade and navigation was the essential task of the Consuls. In Cyprus trade mainly involved exports which depended directly on agriculture. If the harvests were sometimes abundant, drought and locusts could nullify the peasants' hard work who were in addition crippled by taxes. Their situation became so desperate that they were forced to flee. Internal troubles and international events also affected trade and in the middle of the 19th century this was limited to the export of produce from the island and the import of items needed for internal consumption. Furthermore, though Cyprus offered shipping a safe haven from the hazards of navigation, whether storms or pirates, and supplied foodstuffs at an attractive price, maritime traffic off Larnaca went into a clear decline : new direct sea routes with the Levant had been created, the more secure situation in Syria had prompted merchants to set themselves up there, and the island's quarantine regime and relatively high customs dues also played a negative role.

An analysis of using reflectors for distributed denial-of-service attacks

Attackers can render distributed denial-of-service attacks more difficult to defend against by bouncing their flooding traffic off of reflectors ; that is, by spoofing requests from the victim to a large set of Internet servers that will in turn send their combined replies to the victim. The resulting dilution of locality in the flooding stream complicates the victim's abilities both to isolate the attack traffic in order to block it, and to use traceback techniques for locating the source of streams of packets with spoofed source addresses, such as ITRACE [Be00a], probabilistic packet marking [SWKA00], [SP01], and SPIE [S+01]. We discuss a number of possible defenses against reflector attacks, finding that most prove impractical, and then assess the degree to which different forms of reflector traffic will have characteristic signatures that the victim can use to identify and filter out the attack traffic. Our analysis indicates that three types of reflectors pose particularly significant threats: DNS and Gnutella servers, and TCP-based servers (particularly Web servers) running on TCP implementations that suffer from predictable initial sequence numbers. We argue in conclusion in support of "reverse ITRACE" [Ba00] and for the utility of packet traceback techniques that work even for low volume flows, such as SPIE.

Trace zinc and copper concentrations in roadside vegetation and surface soils: a measurement of local atmospheric pollution in Alice, South Africa

The concentration of zinc and copper in 180 grass and associated soil samples collected in triplicate samples were determined. The triplicate field data were averaged to yield mean soil and vegetation metal concentrations at each sample location. The zinc levels ranged from 7.0 ± 1.4(S.D.) — 134.8 ± 6.3(S.D.) μgg‐1, dry weight, in grass and from 0.6 ± 0.2 (S.D.) — 119.5 ± 3.9 (S.D.) μgg‐1, dry weight, in surface soils. The results showed that zinc contents are high close to the road traffic and fall off rapidly with distance from the road edge. Similar studies on copper gave lower values ‐1.0 ± 0.2(S.D.) — 8.1 ± 1.4(S.D.) μgg‐1, dry weight in soil samples which did not show any correlation with distance from road traffic. Analysis of standard soil reference materials (SRM 2710) gave results (Zn, 6636.5 ± 43.7(S.D.); Cu, 2725 ± 49.1(S.D.)) which are found to be in good agreement with certified NIST values (Zn, 6952 ± 91; Cu, 2950 ± 130). Results of spiking experiments with vegetation gave high percentage recoveries for both elements (Zn, 96.6 ± 1.3(S.D.)% and Cu, 95.5 ± 0.5(S.D.)%). Blank determinations were done for background corrections.

Hydrocarbons in seawater, sediment, and oyster from the omani coastal waters

Over half of the world crude oil supply is transported from the Arabian Gulf area via tankers through the narrow Strait of Hormuz, which forms the northern boundary of the Sultanate of Oman. Generally, crude oil tanker traffic off the coast of Oman is relatively heavy and all the vessels entering the Gulf to load at various terminals pass by the coastal line of Oman. The present work plays an essential part on the Omani marine monitoring program. The purpose of this program was to establish baseline levels of selected heavy metals, chlorinated and petroleum hydrocarbons in some marine species. This study aims to assess hydrocarbons in seawater, sediment and rocky oysters from the different sites along Omani coastal waters.

日ノ御埼における一本釣り漁船集団と通航船舶について

日ノ御埼における一本釣り漁船集団と通航船舶について