Although Border Gateway Protocol – BGP is increasingly becoming a multi-purpose protocol, it suffers from security issues regarding bogus announcements for malicious goals. Some of these security breaches are particularly critical for distributed intrusion detection systems that use BGP as their underlay network for interchanging alarms. In this case, assessing the confidence level of these BGP messages helps to prevent internal attacks. Most of the proposals addressing the confidence level of BGP messages rely on complex and time-consuming mechanisms that can also be a potential target for intelligent attacks. In this paper, we propose Gonogo as an out-of-band system based on machine learning to infer the confidence level of the intrusion alarms using just the mandatory header of each BGP message that transports them. Tests using a synthetic data set reflecting the indirect effects of a widespread worm attack over the BGP network show promising results, considering well-known performance metrics, such as recall, accuracy, receiver operating characteristics (ROC), and f1-score.

5G relies on its pervasive and convergent cloud-based architecture to accomplish its futuristic challenge of being the next-generation communication platform. However, the new perspectives opened by 5G networks do not go unnoticed. Regardless of their motivation or objectives, cyberattackers find in the new 5G ecosystem, including its tenancy-driven control plane, an attractive greenfield to create new types of denial of services attacks. In this article, we leverage on the virtualised environment of 5G to propose REPEL – an intelligent resource scaling strategy to mitigate DDoS signalling attacks preserving legitimate traffic. Our prevention-based approach uses games theory to build up a defence front line, able to keep services availability and discourage the attacker. To demonstrate the effectiveness and feasibility of our approach, we feed a queuing model with parameters obtained from a testbed, where simulated subscribers connect to a virtualised evolved packet core prototype. The final results show a dramatic signalling losses reduction, which can ensure the appropriate control plane availability under a DDoS attack.

The IEEE 802.16 is a well known set of standards, which have been developed for global deployment of Metropolitan Area Networks (MANs) in order to provide broadband wireless accesses supporting the integrated transmission of multimedia applications with different Quality of Service (QoS) requirements. In order to achieve the QoS requirements of multimedia applications, the IEEE 802.16 standards offers different scheduling schemes. This paper is concerned with the analytical modelling of the MAC protocol and the analysis of average message delays for real and non-real time traffics in broadband access wireless networks operating under the IEEE 802.16 standard. The message delays results obtained are presented for two scenarios, as a function of the load generated for different types of traffic. In addition, the impact on the network performance caused by some of the parameters utilized as part of the random access mechanism is also investigated. The results obtained through the use of the analytical model proposed in this paper are compared with those obtained with the aid of a simulation tool. The agreement of comparisons involving analytical and simulation results in the examples studied show that the model proposed in this paper could be very useful when utilized to represent and study further behavior characteristics of the end-to-end message delays involved in IEEE 802.16 standard MAC protocol under consideration.

We present a new analysis for human mobility through real traces captured in a recreational environment. The goal of this analysis is to investigate the motion components, in both a qualitative and quantitative way, and thus, to get a better knowledge of pedestrian mobility behavior. Moreover, some results based upon human mobility captured in a real scenario with GPS equipment are presented. In these captured data, we verified that the speed and acceleration components follow a Normal distribution, while the direction angle variation component and the pause time measure follow a Lognormal distribution. Finally, we show that velocity and direction angle change components of captured scenario have a temporal dependence unlike the random mobility models.

In this paper is proposed a real mobility characterization study for wireless devices. For this, we use mobility metrics and statistic analysis to evaluate the behavior of device movement components.

In this paper, we propose an alternative QoS architecture for the IEEE 802.16 Standard, that incorporates a priority based packet scheduling and a new traffic shaping. For this, we present the ideas of a traffic conditioner based on concept of "Fair Marker".

Mobility models try to represent the movement behavior of devices in mobile ad hoc networks. These models are used in performance evaluation of applications and communication systems, allowing the analysis of the mobility's impact. In this context, two individual mobility models for mobile ad hoc networks are proposed in this paper. These models were based in [C Chaing et al. (1998)] and intend to represent a wider movement capability. Using the proposed models it is possible to move in the same direction, in adjacent directions, to accelerate and to stop, avoiding sharp turns and sudden stops. This way, it is tried a closer representation to the real movement of the users in urban environments and roads. In this paper, the models are described analytically by Markov chains. Besides that, some comparisons between the proposed models, the waypoint model and the random walk model are presented through the use of simulations.

The need to offer different service levels on the Internet has encouraged the research in differentiated services (diffserv or DS) (K. Nichols et al., 1998; S. Blake et al., 1998). The article analyses the behavior and evaluates the performance of a fair traffic marker implementation, called Fair Marker (FM), as proposed by H. Kim (1999). The implementation exploits the duality between buffer allocation and token consumption in a token bucket marker in order to enforce fairness among different flows originated from the same subscriber network in a differentiated services (diffserv) domain. The results obtained show that fairness can be achieved when parameters are correctly set. We establish well-defined guidelines to help configure the FM parameters. The results also show that the FM cannot provide fairness in the allocation of excess bandwidth. In order to overcome this problem, we present an extension to the original proposal called Three-Color Fair Marker (TCFM). As an additional contribution, marking strategies proposals are discussed and classified.

The authors consider symmetric multiserver multiqueue systems in the cases of exhaustive and gated service disciplines, and present exact analytical results for the average server cycle and vacation times, as well as approximate closed-form expressions for the average customer waiting time, thus complementing the results obtained by the same authors (1990) for the one-limited service discipline. Arrival processes at each queue are assumed to be Poisson, with the same rate for all queues; service times and walk times are modeled with independent, identically distributed random variables with arbitrary distributions. The two cases in which at most one server or any number of servers can simultaneously attend a queue are considered.>

An analysis of polling schemes with multiple servers is presented where the service discipline at each station is assumed to be of the nonexhaustive (limited) type, i.e. no more than one customer can be removed from a station per visit of a server. The times spent by servers to walk from station to station are assumed to be nonzero and are modeled by independent, identically distributed random variables. The arrival processes at each queue are assumed to be Poisson, and serving times are modeled with independent, identically distributed random variables with arbitrary PDF. The case in which at most one server and the case in which any number of servers can simultaneously attend a queue are separately considered. Under the assumption of balanced traffic (equal arrival rates at all stations), several results concerning the cycle analysis and the stability of such schemes are obtained. A simple, explicit expression that gives an approximation for the steady-state average customer waiting time is derived.>

A TDMA (time-division multiple-access) access-control scheme operating under a preemptive message-based priority discipline is considered and analyzed. The system considered is general, so that an arbitrary number of slots can be allocated to different stations, on a uniformly (equally) spaced basis, in each frame. Under the assumptions of a Poisson message arrival stream and random message lengths governed by a general distribution, it is shown how the Laplace-Stieltjes transform of the actual message waiting time and the delay distributions can easily be obtained, for each priority class, at each of the network stations. Using these results, explicit formulas for any moment of the message delay for any priority class can be obtained. In particular, expressions for the first two moments of the message waiting time and for the average delay of class-k messages are derived.>

The commenter corrects and comments on a few results reported in the paper by H. Takagi (see ibid., vol.COM-35, p.248-50, Feb. 1987). In addition, it is shown how these results can be utilized to give the average message delay for token passing protocols where each network station is allowed to send a maximum of one fixed-length packet per cycle (known as chaining discipline).>

A TDMA access-control scheme operating under a nonpreemptive message-based priority discipline is considered and analyzed. The moment generating function (MGF) of the message waiting-time is obtained, at an arbitrary station of the network, under the assumptions of a Poisson message arrival stream and random message lengths governed by a general distribution, for each priority class. Using these results, explicit formulas for any moment of the message delay can be obtained. In particular, expressions for the average and standard deviation of the message waiting-time are presented, for the case when short (e.g., interactive) messages have priority over longer (e.g., batch) messages.

Two efficient polling (token) schemes, which provide multiaccess coordination for local area networks, are described, analyzed, and compared. The two multiple-access polling protocols described here utilize gated and exhaustive disciplines in ordering the transmission of the messages buffered at each terminal. The delay-throughput performance behavior of polling schemes operating under the above mentioned disciplines is derived. Network terminals are modeled as independent sources, which generate messages in accordance with a renewal process. A queueing theoretic approach is employed in deriving the actual message delay. behavior of both schemes. Several comparisons are presented. Interesting results are obtained when we compare the average message waiting times in the case when the network traffic is completely balanced with the ease when this same traffic is mostly due to a single node. The latter case would arise, for example, m networks employing gateways.