Structured Random Linear Codes (SRLC): Bridging the Gap between Block and Convolutional Codes

Several types of AL-FEC (Application-Level FEC) codes for the Packet Erasure Channel exist. Random Linear Codes (RLC), where redundancy packets consist of random linear combinations of source packets over a certain finite field, are a simple yet efficient coding technique, for instance massively used for Network Coding applications. However the price to pay is a high encoding and decoding complexity, especially when working on $GF(2^8)$, which seriously limits the number of packets in the encoding window. On the opposite, structured block codes have been designed for situations where the set of source packets is known in advance, for instance with file transfer applications. Here the encoding and decoding complexity is controlled, even for huge block sizes, thanks to the sparse nature of the code and advanced decoding techniques that exploit this sparseness (e.g., Structured Gaussian Elimination). But their design also prevents their use in convolutional use-cases featuring an encoding window that slides over a continuous set of incoming packets. In this work we try to bridge the gap between these two code classes, bringing some structure to RLC codes in order to enlarge the use-cases where they can be efficiently used: in convolutional mode (as any RLC code), but also in block mode with either tiny, medium or large block sizes. We also demonstrate how to design compact signaling for these codes (for encoder/decoder synchronization), which is an essential practical aspect.Comment: 7 pages, 12 figure

Protocol Analysis of Any-Source Multicast and Source-Specific Multicast

It is in general recognized that IP multicast routing protocols are fairly complex and non-scalable and its property to make it work ideally requires additional maintenance cost to network administrators and operators. Hence although the Internet community has been doing a significant amount of research works on IP multicast over the last decade and most router vendors already support basic IP multicast routing protocols, there are still deployment problems in the Internet. In this document, we analyze the difficulties of traditional many-to-many communication and the benefit of one-to-many or few-to-many communication. While the former communication model called Any-Source Multicast (ASM) does not require the source address specification, the later communication model called Source-Specific Multicast (SSM) requires the source address specification, when an application joins to the group. We mainly study the difference of the routing protocols between these models

Consideration of Multicast Channel Announcement Architecture

In this document, we propose a new multicast session directory system, «Channel Reflector». One of the goals of this system is to provide a feasible channel announcement mechanism for Source-Specific Multicast (SSM) environment without using traditional SAP advertisement. The main advantage of it is to provide a channel announcement policy and a data distribution area by effective scoping technique. Channel Reflector does not require any protocol change to an end user, therefore, the easy deployment is also one of the benefits. The channel information including the policy configurati- on is written in XML format. Due to an XML's property, network administrators can flexibly prepare independent channel information, and the end user retrieves available channel information as a human-readable information transparently

Implementation Specification of Channel Reflector

In this document, we detail an implementation specification of ``Channel Reflector''. Channel Reflector (CR) offers an effective policy and scope control technique for multicast channel announcement without use of a traditional SAP advertisement. It appears as a hierarchical directory system and each end user accesses this system as a regular Web server and retrieves available channel information via his Web browser. According to this property, we have designed the CR implementation which can work with a common and well-known http server and database implementations. More precisely, our CR has been implemented as modules used with an Apache http server. In addition, while the channel information including the policy configuration is defined in XML format in CR, all the information are converted and stored in MySQL efficiently. Such the implementation strategy reduces the operator's maintenance cost and finally contributes to the easy deployment

Low Latency Low Loss Streaming using In-Network Coding and Caching

International audienceOwing to the rapid growth in high-quality video streaming over the Internet, preserving high-level robustness against data loss and low latency, while maintaining higher data transmission rates, is becoming an increasingly important issue for high-quality real-time delay-sensitive streaming. In this paper, we propose a low latency, low loss streaming mechanism, L4C2, convenient for high-quality delay-sensitive streaming. With L4C2, nodes in the network estimate the acceptable delay and packet loss probability in their uplinks, aiming at retrieving lost data packets from in-network cache and/or coded data packets using in-network coding within an acceptable delay, by extending the Content-Centric Networking (CCN) approach. Further, L4C2 naturally provides multiple paths and multicast technologies to efficiently utilize network resources while sharing network resources fairly with competing data flows by adjusting the video quality when necessary. We validate through comprehensive simulations that L4C2 achieves a high success probability of data transmission considering the acceptable one-way delay, and higher QoE while suppressing the interest and redundant data traffic than the proposed multipath congestion control mechanism in CCN

Scalable Guaranteed-Bandwidth Multicast Service in Software Defined ISP networks

International audienceNew applications where anyone can broadcast video are becoming very popular on smartphones. With the advent of high definition video, ISP providers may take the opportunity to propose new high quality broadcast services to their clients. Because of its centralized control plane, Software Defined Networking (SDN) seems an ideal way to deploy such a service in a flexible and bandwidth-efficient way. But deploying large scale multicast services on SDN requires smart group membership management and a bandwidth reservation mechanism to support QoS guarantees that should neither waste bandwidth nor impact too severely best effort traffic. In this paper, we propose a Network Function Virtualization based solution for Software Defined ISP networks to implement scalable multicast group management. Then, we propose the Lazy Load balancing Multicast (L2BM) routing algorithm for sharing the network capacity in a friendly way between guaranteed-bandwidth multicast traffic and best-effort traffic. Our implementation of the framework made on Floodlight controllers and Open vSwitches is used to study the performance of L2BM

Efficient Pull-based Mobile Video Streaming leveraging In-Network Functions

International audienceThere has been a considerable increase in the demand for high quality mobile video streaming services, while at the same time, the video traffic volume is expected to grow exponentially. Consequently, maintaining high quality of experience (QoE) and saving network resources are becoming crucial challenges to solve. In this paper, we propose a name-based mobile streaming scheme that allows efficient video content delivery by exploiting a smart pulling mechanism designed for information-centric networks (ICNs). The proposed mechanism enables fast packet loss recovery by leveraging in-network caching and coding. Through an experimental evaluation of our mechanism over an open wireless testbed and the Internet, we demonstrate that the proposed scheme leads to higher QoE levels than classical ICN and TCP-based streaming mechanisms

Performance Analysis of a High-Performance Real-Time Application with Several AL-FEC Schemes

International audienceReal-time streaming applications typically require minimizing packet loss and transmission delay so as to keep the best possible playback quality. From this point of view, IP datagram losses (e.g. caused by a congested router, or caused by a short term fading problem with wireless transmissions) have major negative impacts. Although Application Layer Forward Error Correction (AL-FEC) is a useful technique for protecting against packet loss, the playback quality is largely sensitive to the AL-FEC code/codec features and the way they are used. In this work, we consider three FEC schemes for the erasure channel: 2D parity check codes, Reed-Solomon over GF(2^8) codes, and LDPC-Staircase codes, all of them being currently standardized within IETF. We have integrated these FEC schemes in the FECFRAME framework, a framework that is also being standardized at IETF, and whose goal is to integrate AL-FEC schemes in real-time protocol stacks in a simple and flexible way. Then we modified the Digital Video Transport System (DVTS) high-performance real-time video streaming application so that it can benefit from FECFRAME in order to recover from transmission impairments. We then carried out several performance evaluations in order to identify, for a given loss rate, the optimal configuration in which DVTS performs the best

Modular architecture providing convergent and ubiquitous intelligent connectivity for networks beyond 2030

The transition of the networks to support forthcoming beyond 5G (B5G) and 6G services introduces a number of important architectural challenges that force an evolution of existing operational frameworks. Current networks have introduced technical paradigms such as network virtualization, programmability and slicing, being a trend known as network softwarization. Forthcoming B5G and 6G services imposing stringent requirements will motivate a new radical change, augmenting those paradigms with the idea of smartness, pursuing an overall optimization on the usage of network and compute resources in a zero-trust environment. This paper presents a modular architecture under the concept of Convergent and UBiquitous Intelligent Connectivity (CUBIC), conceived to facilitate the aforementioned transition. CUBIC intends to investigate and innovate on the usage, combination and development of novel technologies to accompany the migration of existing networks towards Convergent and Ubiquitous Intelligent Connectivity (CUBIC) solutions, leveraging Artificial Intelligence (AI) mechanisms and Machine Learning (ML) tools in a totally secure environment