Misuse Detection in Consent-based Networks

Consent-based networking, which requires senders to have permission to send traffic, can protect against multiple attacks on the network. Highly dynamic networks like Mobile Ad-hoc Networks (MANETs) require destination-based consent networking, where consent needs to be given to send to a destination in any path. These networks are susceptible to multipath misuses by misbehaving nodes. In this paper, we identify the misuses in destination-based consent networking, and provide solution for detecting and recovering from the misuses. Our solution is based on our previously introduced DIPLOMA architecture. DIPLOMA is a deny-by-default distributed policy enforcement architecture that can protect the end-host services and network bandwidth. DIPLOMA uses capabilities to provide consent for sending traffic. In this paper, we identify how senders and receivers can misuse capabilities by using them in multiple paths, and provide distributed solutions for detecting those misuses. To that end, we modify the capabilities to aid in misuse detection and provide protocols for exchanging information for distributed detection. We also provide efficient algorithms for misuse detection, and protocols for providing proof of misuse. Our solutions can handle privacy issues associated with the exchange of information for misuse detection. We have implemented the misuse detection and recovery in DIPLOMA systems running on Linux operating systems, and conducted extensive experimental evaluation of the system in Orbit MANET testbed. The results show our system is effective in detecting and containing multipath misuses

Approximation algorithms for wavelength assignment

Winkler and Zhang introduced the FIBER MINIMIZATION problem in [3]. They showed that the problem is NP-complete but left the question of approximation algorithms open. We give a simple 2-approximation algorithm for this problem. We also show how ideas from the Dynamic Storage Allocation algorithm of Buchsbaum et al [1] can be used to give an approximation ratio arbitrarily close to 1 provided the problem instance satisfies certain criteria. We also show that these criteria are necessary to obtain an approximation scheme. Our 2-approximation algorithm achieves its guarantee unconditionally. We generalize the problem to a ring network and give a 2 + o(1)-approximation algorithm for this topology. Our techniques also yield a factor-2 approximation for the related problem of PACKING INTERVALS IN INTERVALS, also introduced by Winkler and Zhang in [3].

Optimization Models for the Radio Planning of Wireless Mesh Networks

The classical approach of radio planning in wireless access networks is often tailored as a set covering problem. Such approach is no longer suited for Wireless Mesh Networks (WMNs), where, beside the problem of covering clients, also the wireless network topology must be planned and the tra±c must be routed on wireless links towards mesh access points. In this paper we propose novel optimization models for the planning of WMNs whose objective is to minimize the network installation cost, while providing full coverage to wireless mesh clients. Our mixed integer linear programming models aim at selecting the number and positions of mesh routers and access points, while taking into account in an ac- curate way tra±c routing, interference, rate adaptation, and channel assignment. We provide the optimal solutions of the proposed problem formulations on a set of realistic-size instances and discuss the e®ect of di®erent parameters on the characteristics of the planned networks