Abstract-The IEEE 802.11s draft standard defines a mesh network in which frame delivery is done by forwarding the frame through nodes, called Mesh Points (MPs). To make this possible, it specifies two routing protocols: HWMP and RA-OLSR. Both protocols suffer from scalability issues caused by the use of broadcast messages for discovery and update of routes. In this work, we propose a new routing protocol, the DHT-based Cluster Routing Protocol (DCRP), that improves the scalability of 802.11s networks. Our approach is based on two mechanisms: clustering of nodes and DHT-based searching. Clustering allows to reduce the number of broadcast messages required for routing as well as the amount of routing information broadcasted. DHT-based searching is used to make up for the required routing information that is not diffused by the DCRP itself. Some back-of-the-envelope calculations indicate that our approach increases the scalability of the routing protocol.

Abstract

The following electrocardiographic parameters were related to the degree of mechanical dyssynchrony: QRS duration and notches in QRS. In addition, the patients tend to have highest S amplitude in precordial leads.

Distributed firewall systems emerged with the proposal of protecting individual hosts against attacks originating from inside the network. In these systems, firewall rules are centrally created, then distributed and enforced on all servers that compose the firewall, restricting which services will be available. However, this approach lacks protection against software vulnerabilities that can make network services vulnerable to attacks, since firewalls usually do not scan application protocols. In this sense, from the discovery of any vulnerability until the publication and application of patches there is an exposure window that should be reduced. In this context, this article presents Self-Adaptive Distributed Firewall (SADF). Our approach is based on monitoring hosts and using a vulnerability assessment system to detect vulnerable services, integrated with components capable of deciding and applying firewall rules on affected hosts. In this way, SADF can respond to vulnerabilities discovered in these hosts, helping to mitigate the risk of exploiting the vulnerability. Our system was evaluated in the context of a simulated network environment, where the results achieved demonstrate its viability.