Dinh Thai Bui

Packet delay variation management for a better IEEE1588V2 performance

Designed for the distribution of time, IEEE 1588V2 also called as Precision Time Protocol V2 (PTPV2) is often referred to as a key candidate for synchronization over Packet Switched Networks (PSNs). Unfortunately, as the IETFs Network Time Protocol and unlike the ITU-Ts Synchronous Ethernet, the performance of this protocol strongly depends on Packet Delay Variations (PDVs) produced by the telecom network environment. Such behavior represents a strong issue, particularly considering the severe synchronization requirements of the mobile backhaul segment. This article focuses on different manners to control and to fight out PDVs. After discussing PDV-management principles, via the illustration of some existing mechanisms, we propose a new distributed ranging scheme which allows for optimizing the overall PTPV2 synchronization performance. Finally, considered as a critical mobile backhaul use case, IEEE 1588V2 over Digital Subscriber Line (DSL) is investigated regarding PDV concerns.

Software-Defined LANs for Interconnected Smart Environment

In this paper, we propose a solution to delegate the control and the management of the network connecting the many devices of a smart environment to a software entity, while keeping end-users in control of what is happening in their networks. For this, we rely on the logical manipulation of all connected devices through device abstraction and network programmability. Applying Software Defined Networking (SDN) principles, we propose a software-based solution that we call Software-Defined LANs in order to interconnect devices of smart environments according to the services the users are requesting or expecting.We define the adequate virtualization framework based on Virtual Objects and Communities of Virtual Objects. Using these virtual entities, we apply the SDN architectural principles to define a generic architecture that can be applied to any smart environment. Then we describe a prototype implementing these concepts in the home networking context, through a scenario in which users of two different homes can easily interconnect two private but shareable DLNA devices in a dedicated video-delivery SD-LAN. Finally we provide a discussion of the benefits and challenges of our approach regarding the generalization of SDN principles, autonomic features, Internet of Things scalability, security and privacy aspects enabled by SD-LANs intrinsic properties.

Dual and hybrid PTP modules

the IEEE 1588-2008 standard [1] introduces and specifies Boundary Clock (BC) and Transparent Clock (TC) concepts in order to address stringent time distribution requirements (e.g. 1 µs accuracy for the end application) across a communication network. Both concepts present different strengths and weaknesses which are generally used as arguments to oppose one against the other. This paper, on the contrary, is advocating for the implementation of both functionalities on the same network node with regards to the great commonalities and complementarities between them. Going further on this complementary approach, this contribution proposes a hybrid module aiming at combining different advantages offered respectively by BC and TC concepts.

Supporting multicast and broadcast traffic for groups of connected devices

In order to secure the Internet of Things, we have proposed to split connected devices into groups, called communities of devices. Each of those communities connects devices authorized to communicate with each other using a defined set of applications. To isolate information exchanged within each community, the network can be “sliced”, with each slice being dedicated to a community. However, such a network architecture is challenging to the control of multicast and broadcast traffics, especially when each of the devices can pertain to several communities simultaneously. This paper exposes specific issues regarding multicast and broadcast traffic within the described IoT environment. It proposes an appropriate and innovative solution to work around those issues.

Protocol agnostic On-Path Supports

Targeting the distribution of accurate frequency and time references across Packet Switched Networks (PSNs), the IEEE Std 1588TM-2008 (a.k.a. 1588V2 or PTPV2) standard specifies network infrastructure components intended to reduce the impact of network elements located between the Grandmaster clock and Slave clocks. Also referred to as On-Path Supports (OPS), these PTPV2 build-in network components are the Boundary Clock (BC) and the Transparent Clock (TC). After briefly discussing on both components relatively to their strengths and weaknesses, this paper focuses on the challenging environment imposed by the next generation mobile standard, namely the 3GPP Long Term Evolution (LTE). Addressing security concerns, this standard particularly recommends the use of IPSec tunneling which forbids any use of TCs and BCs. Facing such a challenge, this document proposes innovative protocol-agnostic On-Path Supports which can be seen as complementary to the OPSs of PTPV2.

From Ethernet to Synchronous Ethernet

This article presents a comprehensive overview on the upcoming migration from the current Ethernet infrastructure towards synchronous Ethernet. It first presents within a synchronization perspective a brief description of the current Ethernet and compares it to the SDH/SONET technology. The intent is to outline the current Ethernet gaps in terms of network synchronization. Secondly, it describes the key additional functional blocks, as specified by the ITU-T (study group 15, question 13), enabling Ethernet to support frequency synchronization (or syntonization) and thus yielding to the standardized synchronous Ethernet. Finally, it points out some possible migration scenarios by putting the stress on both technical difficulties and operational investments foreseen during the implementation phase.

Future Spaces: Reinventing the Home Network for Better Security and Automation in the IoT Era

Cyber-Physical Systems (CPSs) are complex systems comprising computation, physical, and networking assets. Used in various domains such as manufacturing, agriculture, vehicles, etc., they blend the control of the virtual and physical worlds. Smart homes are a peculiar type of CPS where the local networking fundamentals have seen little evolution in the past decades, while the context in which home networks operate has drastically evolved. With the advent of the Internet of Things (IoT), the number and diversity of devices connected to our home networks are exploding. Some of those devices are poorly secured and put users’ data privacy and security at risk. At the same time, administrating a home network has remained a tedious chore, requiring skills from un-savvy users. We present Future Spaces, an end-to-end hardware-software prototype providing fine-grained control over IoT connectivity to enable easy and secure management of smart homes. Relying on Software-Defined Networking-enabled home gateways and the virtualization of network functions in the cloud, we achieve advanced networking security and automation through the definition of isolated, usage-oriented slices. This disrupts how users discover, control and share their connected assets across multiple domains, smoothly adapting to various usage contexts.

A generic interface for Open vSwitch

In this paper, we describe a new generic interface to a software-defined switch allowing the controller to inform the switch of the existence of an external function. Through the same generic interface, the switch can call for the external function during its internal forwarding processes. Such innovating interface allows the network operator to add new functionalities to the switch, in the form of external functions, without having to upgrade the switch core forwarding processes. This should allow the operator for saving his/her OPEX After describing the new concept, we present the implementation of such a concept onto the open-source software-based Open vSwitch.