Cooperative announcement-based caching for video-on-demand streaming

Recently, video-on-demand (VoD) streaming services like Netflix and Hulu have gained a lot of popularity. This has led to a strong increase in bandwidth capacity requirements in the network. To reduce this network load, the design of appropriate caching strategies is of utmost importance. Based on the fact that, typically, a video stream is temporally segmented into smaller chunks that can be accessed and decoded independently, cache replacement strategies have been developed that take advantage of this temporal structure in the video. In this paper, two caching strategies are proposed that additionally take advantage of the phenomenon of binge watching, where users stream multiple consecutive episodes of the same series, reported by recent user behavior studies to become the everyday behavior. Taking into account this information allows us to predict future segment requests, even before the video playout has started. Two strategies are proposed, both with a different level of coordination between the caches in the network. Using a VoD request trace based on binge watching user characteristics, the presented algorithms have been thoroughly evaluated in multiple network topologies with different characteristics, showing their general applicability. It was shown that in a realistic scenario, the proposed election-based caching strategy can outperform the state-of-the-art by 20% in terms of cache hit ratio while using 4% less network bandwidth

Study and analysis of mobility, security, and caching issues in CCN

Existing architecture of Internet is IP-centric, having capability to cope with the needs of the Internet users. Due to the recent advancements and emerging technologies, a need to have ubiquitous connectivity has become the primary focus. Increasing demands for location-independent content raised the requirement of a new architecture and hence it became a research challenge. Content Centric Networking (CCN) paradigm emerges as an alternative to IP-centric model and is based on name-based forwarding and in-network data caching. It is likely to address certain challenges that have not been solved by IP-based protocols in wireless networks. Three important factors that require significant research related to CCN are mobility, security, and caching. While a number of studies have been conducted on CCN and its proposed technologies, none of the studies target all three significant research directions in a single article, to the best of our knowledge. This paper is an attempt to discuss the three factors together within context of each other. In this paper, we discuss and analyze basics of CCN principles with distributed properties of caching, mobility, and secure access control. Different comparisons are made to examine the strengths and weaknesses of each aforementioned aspect in detail. The final discussion aims to identify the open research challenges and some future trends for CCN deployment on a large scale

Design of Scalable On-Demand Video Streaming Systems Leveraging Video Viewing Patterns

The explosive growth in on-demand access of video across all forms of delivery (Internet, traditional cable, IPTV, wireless) has renewed the interest in scalable delivery methods. Approaches using Content Delivery Networks (CDNs), Peer-to-Peer (P2P) approaches, and their combinations have been proposed as viable options to ease the load on servers and network links. However, there has been little focus on how to take advantage of user viewing patterns to understand their impact on existing mechanisms and to design new solutions that improve the streaming service quality. In this dissertation, we leverage on the observation that users watch only a small portion of videos to understand the limits of existing designs and to optimize two scalable approaches -- the content placement and P2P Video-on-Demand (VoD) streaming. Then, we present our novel scalable system called Joint-Family which enables adaptive bitrate streaming (ABR) in P2P VoD, supporting user viewing patterns. We first provide evidence of such user viewing behavior from data collected from a nationally deployed VoD service. In contrast to using a simplistic popularity-based placement and traditionally proposed caching strategies (such as CDNs), we use a Mixed Integer Programming formulation to model the placement problem and employ an innovative approach that scales well. We have performed detailed simulations using actual traces of user viewing sessions (including stream control operations such as pause, fast-forward, and rewind). Our results show that the use of segment-based placement strategy yields substantial savings in both disk storage requirements at origin servers/VHOs as well as network bandwidth use. For example, compared to a simple caching scheme using full videos, our MIP-based placement using segments can achieve up to 71% reduction in peak link bandwidth usage. Secondly, we note that the policies adopted in existing P2P VoD systems have not taken user viewing behavior -- that users abandon videos -- into account. We show that abandonment can result in increased interruptions and wasted resources. As a result, we reconsider the set of policies to use in the presence of abandonment. Our goal is to balance the conflicting needs of delivering videos without interruptions while minimizing wastage. We find that an Earliest-First chunk selection policy in conjunction with the Earliest-Deadline peer selection policy allows us to achieve high download rates. We take advantage of abandonment by converting peers to "partial seeds"; this increases capacity. We minimize wastage by using a playback lookahead window. We use analysis and simulation experiments using real-world traces to show the effectiveness of our approach. Finally, we propose Joint-Family, a protocol that combines P2P and adaptive bitrate (ABR) streaming for VoD. While P2P for VoD and ABR have been proposed previously, they have not been studied together because they attempt to tackle problems with seemingly orthogonal goals. We motivate our approach through analysis that overcomes a misconception resulting from prior analytical work, and show that the popularity of a P2P swarm and seed staying time has a significant bearing on the achievable per-receiver download rate. Specifically, our analysis shows that popularity affects swarm efficiency when seeds stay "long enough". We also show that ABR in a P2P setting helps viewers achieve higher playback rates and/or fewer interruptions. We develop the Joint-Family protocol based on the observations from our analysis. Peers in Joint-Family simultaneously participate in multiple swarms to exchange chunks of different bitrates. We adopt chunk, bitrate, and peer selection policies that minimize occurrence of interruptions while delivering high quality video and improving the efficiency of the system. Using traces from a large-scale commercial VoD service, we compare Joint-Family with existing approaches for P2P VoD and show that viewers in Joint-Family enjoy higher playback rates with minimal interruption, irrespective of video popularity

Quality of Service Issues in Internet Web Services

Editorial special section on "Quality of Service Issues in Internet Web Services

Network architecture in a large-scale fully interactive VOD system based on hybrid multicast-unicast streaming.

Chan Kwun-chung.Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.Includes bibliographical references (leaves 71-73).Abstracts in English and Chinese.摘要 --- p.IIABSTRACT --- p.IIIACKNOWLEDGEMENT --- p.VTABLE OF CONTENTS --- p.VILIST OF FIGURES --- p.XLIST OF SYMBOLS --- p.XIIChapter 1. --- INTRODUCTION --- p.1Chapter 1.1 --- Contributions --- p.3Chapter 1.2 --- Organization of the Thesis --- p.4Chapter 1.3 --- Publications --- p.5Chapter 2. --- RELATED WORKS --- p.6Chapter 2.1 --- Previous VOD System --- p.7Chapter 2.1.1 --- Service Model --- p.7Chapter 2.1.1.1 --- Unicast VOD --- p.7Chapter 2.1.1.2 --- Multicast VOD --- p.8Chapter 2.1.2 --- Architecture --- p.9Chapter 2.1.2.1 --- Centralized Architecture --- p.9Chapter 2.1.2.2 --- Distributed Architecture --- p.10Chapter 2.1.3 --- Interactive Function --- p.11Chapter 2.1.3.1 --- Limited Interactive Function --- p.11Chapter 2.1.3.2 --- Unlimited Interactive Function --- p.11Chapter 2.1.4 --- Split and Merge Operation --- p.12Chapter 2.1.4.1 --- SAM Scheme (Split and Merge) --- p.12Chapter 2.1.4.2 --- SRMDRU Scheme (Single Rate Multicast Double Rate Unicast) --- p.14Chapter 2.2 --- Previous Caching Algorithm --- p.15Chapter 2.2.1 --- LFU (Least Frequently Used) --- p.15Chapter 2.2.2 --- LRU (Least Recently Used) --- p.15Chapter 2.2.3 --- Media Stream Caching --- p.15Chapter 3. --- DESIGN OFA NOVEL VOD SYSTEM --- p.17Chapter 3.1 --- System Architecture --- p.18Chapter 3.1.1 --- Multicast Video Server Cluster (MVSC) --- p.19Chapter 3.1.2 --- Unicast Video Server Cluster (UVSC) --- p.20Chapter 3.1.3 --- Multicast Backbone Network (MBN) --- p.20Chapter 3.1.4 --- Local Distribution Network (LDN) --- p.21Chapter 3.1.5 --- Distributed Interactive Server (DIS) --- p.21Chapter 3.1.6 --- Distributed Proxy Server (DPS) --- p.22Chapter 3.1.7 --- Client Station (CS) --- p.22Chapter 3.2 --- Batched Multicast Transmission --- p.24Chapter 3.3 --- Split and Merge Operation --- p.26Chapter 3.4 --- Interactive Function --- p.31Chapter 3.4.1 --- Pause --- p.31Chapter 3.4.2 --- Slow Motion --- p.35Chapter 3.4.3 --- Various Speed Fast Forward / Fast Rewind (FF/REW) --- p.37Chapter 3.4.4 --- Jump Forward/Jump Backward (JF/JB) --- p.42Chapter 3.5 --- Performance Analysis --- p.46Chapter 3.5.1 --- Model --- p.46Chapter 3.5.2 --- System Parameters --- p.49Chapter 3.5.3 --- Results --- p.49Chapter 4. --- DESIGN OF A VIDEO PROXY SYSTEM --- p.57Chapter 4.1 --- Video Proxy System --- p.58Chapter 4.1.1 --- Priority Function --- p.59Chapter 4.1.2 --- Two-Stage Replacement Policy --- p.60Chapter 4.1.3 --- Caching Policy --- p.61Chapter 4.2 --- Performance Evaluation --- p.63Chapter 4.2.1 --- Simulation Environment --- p.63Chapter 4.2.2 --- Performance Metric --- p.64Chapter 4.2.3 --- Results --- p.64Chapter 5. --- CONCLUSION --- p.69BIBLIOGRAPHY --- p.7