Rafael Pasquini

An Architecture for Mobility Support in a Next-Generation Internet

The current internetworking architecture presents some limitations to naturally support mobility, security and multi- homing. Among the limitations, the IP semantic overload seems to be a primary issue to be considered. In this paper we present a next generation internetworking architecture to overcome the IP semantic overload by introducing an identity layer located between the network and transport layers. This new layer provides a stable cryptographic identifier for end-hosts and seamlessly allows the deployment of new services, such as mobility, multi-homing and security. A prototype was implemented and evaluated considering some mobility scenarios, including intra-domain, inter-domain and simultaneous node mobility.

Towards the Use of XOR-Based Routing Protocols in Vehicular Ad Hoc Networks

In this paper we present a performance analysis of XOR-based flat routing protocols in high mobility conditions, considering a vehicular ad hoc network (VANET) formed in a highway scenario. First, we describe an XOR-based protocol that incorporates several adaptations of the existing XOR-based routing algorithms for wired networks, in order to cope with the network mobility. Then we propose an improved version of it, XORi, which modifies the protocols information gathering process to accommodate the specific dynamic nature of VANETs topology. Finally, we evaluate the performance of XOR-based protocols with other topology-based routing protocols. Simulation results allow us to characterize the performance of this class of protocols through the comparison of the packet delivery ratio, end-to-end path delay and average number of path hops. When a moderate density of nodes is considered, simulations show that XOR-based algorithms achieve almost the same packet delivery rate as link state algorithms, such as OLSR, while for high density of nodes XOR-based algorithms scale better in terms of delay when compared to source routing algorithms, such as DSR.

Domain Identifiers in a Next Generation Internet Architecture

In this paper we make the domain entity a first class citizen. The concept of Domain Identifiers (DIDs) is introduced to effectively bring the domains to the next generation Internet scenario. The paper presents an architecture to address challenging next generation Internet requirements such as node and domain mobility, multi-homing, security, network composition and inter-domain routing. Although our architecture supports all the mentioned requirements, the focus of this paper is specifically on node and domain mobility in order to evaluate and compare the advantages of having DIDs for facilitating the mobility. First, we present the generic Next Generation Internet architecture proposal and its envisioned scenario. Then, we show how to instantiate it to work together with the current Internet. We have developed a prototype to evaluate our proposal and we depict results related to node and domain mobility under this gradual deployment scenario using the Internet as the core.

Hamming DHT: Taming the similarity search

The semantic meaning of a content is frequently represented by content vectors in which each dimension represents an attribute of this content, such as, keywords in a text, colors in a picture or profile information in a social network. However, one important challenge in this semantic context is the storage and retrieval of similar contents, such as the search for similar images assisting a medical procedure. Based on it, this paper presents a new Distributed Hash Table (DHT), called Hamming DHT, in which Locality Sensitive Hashing (LSH) functions, specially the Random Hyperplane Hashing (RHH), are used to generate content identifiers, propitiating a scenario in which similar contents are stored in peers nearly located in the indexing space of the proposed DHT. The evaluations of this work simulate profiles in a social network to verify if the proposed DHT is capable of reducing the number of hops required in order to improve the recall in the context of a similarity search.

On the analysis of multicast traffic over the Entity Title Architecture

New applications bring a new set of requirements that the Internet is not able to satisfy in a proper way. Internet architecture must be reviewed and researchers from all over the world are engaged in the design of a new Internet. Software Defined Networking (SDN), which is materialized in OpenFlow, represents an extraordinary opportunity to rethink computer networks. In this paper, taking advantage of SDN and the concepts of our previous work regarding the Entity Title Model, we present a proof of concept OpenFlow based implementation of the Entity Title Architecture. It is a clean slate network architecture for future networks where multicast and mobility are seamlessly provided. By using this implementation, we describe some experiments conducted and present a comparison between a video application implemented first, using the TCP/IP stack and then using our architecture focusing on its multicast capabilities and by consequently reducing bandwidth consumption. The results presented in this paper show that this consumption near the source by using our architecture remains constant while using TCP/IP it increases monotonically.

Performance analysis of XOR-based routing in urban vehicular ad hoc networks

This paper presents the URBAN_XOR1 protocol, an XOR-based flat routing mechanism developed for vehicular ad hoc networks (VANETs) formed in urban scenarios. The paper firstly describes the URBAN_XOR routing principle, which requires reduced knowledge about the set of nodes present in the VANET in order to provide traffic forwarding. Basically, the URBAN XOR protocol introduces the concept of local visibility, prioritizing the insertion of closer neighbors (in number of hops) in the routing tables, and simplifying the management of the frequent network mobility found in VANETs. Then, the performance of the proposed URBAN_XOR protocol is compared through simulation with other topology-based and position-based protocols, characterizing its performance in terms of path availability ratio, end-to-end delay, path length and path duration. The results reveal that URBAN_XOR contributes for the overall network stability, reducing the end-to-end delay due to its ability of generating shorter paths. At the same time, URBAN_XOR exhibits path availability similar to other topology-based protocols, but exhibiting better path duration times.

An architecture for autonomic management of ambient networks

This paper proposes an architecture for Ambient Networks (AN) management, which is based on components such as Autonomic Networking and Policy Based Network Management. The main goal is to allow AN management aligned to the network requirements, incorporating functionalities such as self-configuration, self-management, self-healing and self-protection. In the proposed architecture, all these functionalities are controlled by a distributed policy-based system, allowing network configuration based on business policies.

An implementation of an OSPF-TE to support GMPLS-controlled all-optical WDM networks

GMPLS-controlled all-optical networks are the promise to handle the increasing volume of IP traffic. The GMPLS routing and signaling protocols, mainly OSPF and RSVP, work in such a way that the route calculation for optical circuits does not take into account the label (lambda) availability. This is not optimal in terms of network usage and blocking probability of new circuits. To deal with this scenario, more efficient RWA algorithms could be used to calculate the route and the wavelength assignment at one time. These RWA engines need to know the optical topology in a way that is not described by the current OSPF standards. This paper proposes Traffic Engineering extensions to the OSPF protocol to enable the GMPLS control plane to take advantage of the most effective RWA classes. A prototype was developed and deployed in an optical-simulated copper-based network to verify its feasibility based on the bandwidth overhead generated in the control plane.

HCube: A Server-centric Data Center Structure for Similarity Search

The information society is facing a sharp increase in the amount of information driven by the plethora of new applications that sprouts all the time. The amount of data now circulating on the Internet is over zettabytes (ZB), resulting in a scenario defined in the literature as Big Data. In order to handle such challenging scenario, the deployed solutions rely not only on massive storage, memory and processing capacity installed in Data Centers (DC) maintained by big players all over the globe, but also on shrewd computational techniques, such as Big Table, MapReduce and Dynamo. In this context, this work presents a DC structure designed to support the similarity search. The proposed solution aims at concentrating similar data on servers physically close within a DC, accelerating the recovery of all data related to searches performed using a primitive get(k, sim), in which k represents the query identifier, i.e., the data used as reference, and sim a similarity level.

Semantically enriched services to understand the need of entities

Researchers from all over the world are engaged in the design of a new Internet, and Software-Defined Networking (SDN) is one of the results of this engagement. Net-Ontology uses a SDN approach to bring semantics to the intermediate network layers and make them capable of handling application requirements and adapt their behaviour over time as required. In this paper we present an experimental evaluation of Net-Ontology and a feature comparison against the traditional TCP/IP stack. This paper extends our earlier work towards a Future Internet, showing a viable approach to introduce semantics at network lower layers by contributing to bring richer and efficient services.