Post Sockets: Towards an Evolvable Network Transport Interface

The traditional Sockets API is showing its age, and no longer provides effective support for modern networked applications. This has led to a proliferation of non-standard extensions, alternative APIs, and workarounds that enable new features and allow applications to make good use of the network, but are difficult to use, and require expert knowledge that is not widespread. In this paper, we present Post Sockets, a proposed new standard network API, that is designed to support modern network transport protocols and features, while raising the level of abstraction and enhancing usability. Specifically, Post Sockets aims to give portable applications the ability to use a clear, messages based, interface to multi-path and multi-stream transports, rendezvous and connection racing, and fast connection re-establishment

Transparent network-assisted flow mobility for multimedia applications in IMS environments

Cellular network operators are striving to solve the problem caused by the increasing volume of traffic over their networks. Given the proliferation of multi-interface devices, offloading part of the traffic to available access networks (e. g., WiFi or 3G access networks, even from other operators) seems to be a promising alternative. Here, we propose an IMS-compatible solution for flow mobility between access networks that exhibits two key features: flow mobility is transparent to both local applications at mobile nodes and their communication peers (e. g., multimedia content servers), and mobility operations are assisted by the network, so the home network supports the terminal in the process of access network discovery, and provides the terminal with policies that meet visited and home operators' roaming agreements while optimizing the use of their networks. The proposed solution has been validated using a real IMS testbed with Ethernet and WiFi access networks, where the mobility of UDP and TCP flows has been tested.The work in this article has been partially granted by the Madrid Community through the MEDIANET project (S-2009/TIC-1468) and by the Celtic UP-TO-US project (TSI-020400-2010-114)Publicad

Evaluating IP security and mobility on lightweight hardware

This work presents an empirical evaluation of applicability of selected existing IP security and mobility mechanisms to lightweight mobile devices and network components with limited resources and capabilities. In particular, we consider the Host Identity Protocol (HIP), recently specified by the IETF for achieving authentication, secure mobility and multihoming, data protection and prevention of several types of attacks. HIP uses the Diffie-Hellman protocol to establish a shared secret for two hosts, digital signatures to provide integrity of control plane and IPsec ESP encryption to protect user data. These computationally expensive operations might easily stress CPU, memory and battery resources of a lightweight client, as well as negatively affect data throughput and latency.We describe our porting experience with HIP on an embedded Linux PDA, a Symbian-based smartphone and two OpenWrt Wi-Fi access routers, thereby contributing to the protocol deployment. We present a set of measurement results of different HIP operations on these devices and evaluate the impact of public-key cryptography on the processor load, memory usage and battery lifetime, as well as the influence of the IPsec encryption on Round-Trip Time and TCP throughput. In addition, we assess how the lightweight hardware of a mobile handheld or a Wi-Fi access router in turn affects the duration of certain protocol operations including HIP base exchange, HIP mobility update, puzzle solving procedure and generation of an asymmetric key pair. After analyzing the empirical results we make conclusions and recommendations on applicability of unmodified HIP and IPsec to resource-constrained mobile devices. We also survey related work and draw parallels with our own research results

Mobility Support in User-Centric Networks

In this paper, an overview of challenges and requirements for mobility management in user-centric networks is given, and a new distributed and dynamic per-application mobility management solution is presented. After a brief summary of generic mobility management concepts, existing approaches from the distributed and peer-to-peer mobility management literature are introduced, along with their applicability or shortcomings in the UCN environment. Possible approaches to deal with the decentralized and highly dynamic nature of UCNs are also provided with a discussion and an introduction to potential future work

Wireless mesh networks for smart-grids

Tese de mestrado. Mestrado Integrado em Engenharia Electrotécnica e de Computadores - Major Telecomunicações. Faculdade de Engenharia. Universidade do Porto. 201