Roberto Canonico

An Overlay Tree Building Control Protocol

TBCP is a generic Tree Building Control Protocol designed to build overlay spanning trees among participants of a multicast session, without any specific help from the network routers. TBCP therefore falls into the general category of protocols and mechanisms often referred to as Application-Level Multicasting. TBCP is an efficient, distributed protocol that operates with partial knowledge of the group membership and restricted network topology information. One of the major strategies in TBCP is to reduce convergence time by building as good a tree as possible early on, given the restricted membership/topology information available at the different nodes of the tree. We analyse our TBCP protocol by means of simulations, which shows its suitability for purpose.

Integrating a network IDS into an open source Cloud Computing environment

The success of the Cloud Computing paradigm may be jeopardized by concerns about the risk of misuse of this model aimed at conducting illegal activities. In this paper we address the issue of detecting Denial of Service attacks performed by means of resources acquired on-demand on a Cloud Computing platform. To this purpose, we propose to investigate the consequences of the use of a distributed strategy to detect and block attacks, or other malicious activities, originated by misbehaving customers of a Cloud Computing provider. In order to check the viability of our approach, we also evaluate the impact on performance of our proposed solution. This paper presents the installation and deployment experience of a distributed defence strategy and illustrates the preliminary results of the performance evaluation.

Scalable adaptive hierarchical clustering

We propose a new application-level clustering algorithm capable of building an overlay spanning tree among participants of large multicast sessions, without any specific help from the network routers. The algorithm and associated protocol are shown to exhibit scalable properties.

Scalability of a mobile cloud management system

Ubiquitous network access allows people to access an ever increasing range of services from a variety of mobile terminals, including laptops, tablets and smartphones. A flexible and economically efficient way of provisioning such services is through Cloud Computing. Assuming that several cloud-enabled datacenters are made available at the edges of the Internet, service providers may take advantage of them by optimally locating service instances as close as possible to their users. By localizing traffic at the edges of access networks, such an approach may result beneficial for both service and network providers. In this paper we present Follow-Me Cloud (FMC), a technology developed at NEC Laboratories Europe that allows transparent migration of services in TCP/IP networks, thanks to the dynamic configuration of a set of coordinated OpenFlow switches located at the edge of the network. In particular, in this paper we analyze the scalability properties of an FMC-based system and propose a role separation strategy based on distribution of control plane functions which enables scale-out of the system. By means of simulation, we prove that the application of the proposed separation strategy results in less state retained by individual OpenFlow controllers and in more effective localization of network traffic.

Detecting backoff misbehaviour in IEEE 802.11 EDCA

In this paper, we suggest the use of the chi-square test for detecting backoff misbehaviour in IEEE 802.11 EDCA networks. A performance evaluation is performed to compare the chi-square test with two other methods, known in the literature. To perform a suitable comparison, these two methods are extended to support EDCA and the BEB mechanism. We assume a misbehaviour model, which can be easily executed by a selfish user. We show that the chi-square test outperforms the other methods in terms of the probability of misbehaviour detection and time required to positively identify a misbehaving node. Copyright

System-Level Virtualization and Mobile IP to Support Service Mobility

In many areas of ICT the use of virtualization techniques has decoupled the binding between physical resources and functional roles assigned to them. While the use of virtualization in computing systems is already extremely popular, similar forms of virtualization have been proposed for the network infrastructure as well. In such a context, we propose a new paradigm that aims at extending the concept of virtualization to network services, by decoupling service execution environments and their physical location. We call this paradigm Service Switching. In a Service Switching environment, service instances may be dynamically migrated across geographically dispersed data centers to pursue better usage of both network and computing resources.

Impact of Contention Window Cheating on Single-Hop IEEE 802.11e MANETs

This paper presents a work in progress which deals with the important and unresolved problem of node misbehavior. A realistic approach is used to determine the impact of contention window manipulation on IEEE 802.11e ad-hoc networks. It is explained why such networks are more prone to misbehavior. Novel results pertaining to the 802.11e standard are presented. Simulation analysis is done for several scenarios with a distinction made for uplink and downlink traffic. It is shown that a misbehaving node can jeopardize network performance, therefore, countermeasures to this problem need to be developed.

Transparent migration of virtual infrastructures in large datacenters for Cloud computing

Cloud-enabled datacenters need advanced support for an integrated management of platform virtualization technologies. The networking infrastructure of large-scale datacenters is implemented according to redundant multi-tiered architectures whose layers operate at Layer 3 of the networking stack. Splitting the network infrastructure of a datacenter in a number of IP subnets, however, creates limits to the migration of Virtual Machines, reducing the possibility for administrators to efficiently balance the load and reduce the energy consumption of the whole infrastructure. In this paper we propose an innovative solution that allows transparent migration of Virtual Machines across the whole datacenter, based on the coordinated use of NAT rules that need to be consistently managed across the layers of the datacenter networking infrastructure. We describe in details how our approach can be easily implemented with current network devices without any modification to their hardware and present an experimental evaluation of an early prototype of our solution.

Interactive Multimedia on Next Generation Networks

Content delivery network architectures are initiatives designed to support the effective delivery of continuous and discrete media to end-users. Mobile devices are now capable of exploiting services such as content delivery, but with the protocols governing the content delivery networks designed for wired networked topologies; an assessment of the impact of mobile devices on the network has never been undertaken. Wireless devices access causes significant issues in the ability of the media transport system to function efficiently or as intended. This paper will highlight the current content delivery architectures available, their level of support for mobile devices and the issues therein.

Analysis of the handover procedure in Follow-Me Cloud

Follow-Me Cloud (FMC) allows transparent migration of end-points (users and services) in TCP/IP networks. In this paper we describe in details the FMC handover procedures and analyze the parameters that may affect their performance. Our analysis suggests possible optimizations for such procedures.