Πολυμεσικό Υλικό στο Internet: Συγχρονισμός, Επεξεργασία και Διακίνηση Β. Μάγκλαρης <[email protected]> Multimedia content Μ. Γραμματικού <[email protected]> Δ. Καλογεράς <[email protected]> delivery in the Internet: www.netmode.ntua.gr CDNs, Real Time Streaming, Multimedia platforms & video service providers Άδεια Χρήσης Το παρόν εκπαιδευτικό υλικό υπόκειται σε άδειες χρήσης Creative Commons. Για εκπαιδευτικό υλικό, όπως εικόνες, που υπόκειται σε άδεια χρήσης άλλου τύπου, αυτή πρέπει να αναφέρεται ρητώς. Outline • Content Delivery Networks (CDNs) • Video on Demand servers/clouds • Real Time Streaming Content Delivery Networks (CDNs) http://en.wikipedia.org/wiki/Content_delivery_network • The first generation CDNs were not encountered before the late 90′s • CDN is a large distributed system of servers deployed in multiple data centers across the Internet • It serves content to end-users with high availability and high performance • It serves a large fraction of the Internet content : – including web objects (text, graphics and scripts), downloadable objects (media files, software, documents), applications (e-commerce, portals), live steaming media, on-demand streaming media, and social networks Single server distribution and CDN distribution Notable Content Delivery Service Providers http://en.wikipedia.org/wiki/Content_delivery_network Free CDNs[edit] Telco CDNs[edit] •BootstrapCDN •AT&T Inc. •CloudFlare •Bharti Airtel •Coral Content Distribution Network •Bell Canada •Incapsula (free version with Incapsula advertisement) •BT Group Traditional commercial CDNs[edit] •Deutsche Telekom •Akamai Technologies •Hibernia Networks •Amazon CloudFront •KT (formerly Korea Telecom) •Aryaka •KPN •Windows Azure CDN •Level 3 Communications •CacheFly •MegaFon •CDNetworks •NTT •ChinaCache •Pacnet •Cotendo (acquired by Akamai) •PCCW •Distil Networks •Qualitynet •EdgeCast Networks •SingTel •Highwinds Network Group •SK Broadband •HP Cloud Services •Tata Communications •Incapsula •TeliaSonera •Internap •Telecom Argentina •LeaseWeb •Telecom Italia •Level 3 Communications •Telecom New Zealand •Limelight Networks •Telefonica •MaxCDN •Telenor •MegaFon •Telstra •MetaCDN •Telus •Mirror Image Internet •Turk Telekom •NACEVI •Verizon •OnApp Commercial CDNs using P2P for delivery[edit] •OVH •BitTorrent, Inc. •Rackspace Cloud Files •Internap •Speedera Networks (acquired by Akamai) •Pando Networks •StreamZilla CDN Europe •Rawflow CDN 2014 – 2017: Operations and Analytics http://www.reportsnreports.com/reports/287274-cdn-2014-2017-operations-and- analytics.html • CDN (Content Delivery Network) revenue is projected at $3.36 billion in 2014, up 19%,directed by user appetite for self-selected content • Total 2013 commercial value of media and entertainment video (views and advertising), movie/TV files, music listening and downloads (including self-hosting entities such as Google and Amazon) stood at $3.35 billion, of which $1.05 billion (31.3%) was delivered through CDN contracts • Video viewing and advertising (combining self-hosted networks), TV/ movies and music accounted for 2.4+ billion gigabytes of data transfer, worth $1.6 billion in commercial market value (bandwidth and co-lo fees only), when priced at prevailing rates and against a volume (gigabytes delivered) model. • CDNs include Akamai Technologies, Limelight Networks, Cd Networks, China Cache, Mirror Image, Level 3, High winds, Cloud flare, Tata Communications and MaxCDN, among others Published By: AccuStream Research Content Delivery Networks http://www.globaldots.com/the-history-of-content-delivery-networks-cdn • In the past, the development of CDNs sought to deal with extreme bandwidth pressures, first as video streaming was growing in demand as well as the number of content providers • Now, CDNs are a continual trend, with the emergence of utility - cloud computing, charging end-users on demand and involving all layers of cloud computing: – SaaS (Software as a Service), e.g. Google Docs, Amazon CloudFront – PaaS (Platform as a Service) e.g. Google App Engine – IaaS (Infrastructure as a Service), e.g. GRNET Okeanos, Amazon EC2 Layers of Cloud Computing http://www.globaldots.com/the-history-of-content-delivery-networks-cdn Content Νetworking Τechniques • The Internet was designed according to the end-to-end neutrality principle. Core network : simple and moves the intelligence to the network end-points (hosts, clients) • CDNs distribute a variety of applications employing techniques to optimize content delivery. The resulting tightly integrated overlay uses web caching, server-load balancing, request routing, and content services – Web caches store popular content on servers that have the greatest demand for the content requested – Server-load balancing uses one or more techniques including service- based (global load balancing) or hardware-based • A variety of algorithms are used to route appropriately the request. These include Global Server Load Balancing, DNS-based request routing, Dynamic metafile generation, HTML rewriting and anycasting Content Delivery Networks (CDNs) Content Delivery Networks State of the Art, Insights, and Imperatives_2008, Mukaddim Pathan, Rajkumar Buyya and Athena Vakali • Most CDNs are operated as an Application Service Provider (ASP) on the Internet (also known as on- demand software or SaaS) targeting Content Providers, web administrators etc., wishing to optimize delivery to end-users • CDN Service and Functionalities: – Storage and Management of content – Distribution of content among edge servers – Cache management – Delivery of encoded media – Backup and disaster recovery solutions – Monitoring and Performance P2P and Private CDNs • Peer-to-peer CDNs – In P2P content-delivery networks, clients provide resources as well as use them, so the content serving capacity of P2P networks can actually increase as more users begin to access the content • Private CDNs – The owners create their own CDN – A private CDN consists of Points of Present (PoPs) that are only serving content for their owner Top International CDNs make deals directly with ISPs and/or Internet Exchanges http://blog.streamingmedia.com/2014/07/apples-cdn-now-live.html https://peering.google.com/about/ • Apple’s CDN Now Live: Has Paid Deals With ISPs, Massive Capacity In Place • Google Peering and Content Delivery – Data centers – Backbone – Edge Points of Presence (POPs) – Google's edge caching infrastructure • Netflix Announces New Content Delivery Network, Offering Free Caches To ISPs A Pioneer Content Delivery Network (CDN): Akamai http://www.akamai.com/html/about/company_history.html Erik Nygren, Ramesh K. Sitaraman, Jennifer Sun, The Akamai Network: A Platform for High-Performance Internet Applications • Akamai's beginnings lie in a challenge posed by World Wide Web inventor Tim Berners-Lee at MIT in early 1995 • The company launched commercial service in April 1999 • The platform is made up of a distributed network of servers and intelligent software, delivering over two trillion interactions daily • The Akamai Intelligent Platform is constantly monitoring Web conditions to: – Identify, absorb, and block security threats – Provide instant device-level detection and optimization – Make decisions based on comprehensive knowledge of network conditions – Present unprecedented business and technical insights Akamai Erik Nygren, Ramesh K. Sitaraman, Jennifer Sun, “The Akamai Network: A Platform for High-Performance Internet Applications”, ACM SIGOPS Operating Systems Review, Vol. 44, No 3, July 2010 The figure above shows how Akamai maintained high connectivity for customers during the 2008 cable cuts that caused widespread Internet outages in the Middle East, Asia, and Africa. Video-on-Demand http://en.wikipedia.org/wiki/Video_on_demand http://en.wikipedia.org/wiki/IPTV • Video-on-Demand (VoD) are systems which allow users to select and watch/listen to video or audio content when they choose to, rather than having to watch at a specific broadcast time. IPTV technology is often used to bring video on demand to televisions and personal computers • IPTV or IP/TV was developed as a multimedia service for television/video/audio/text/graphics/data delivered over IP based networks managed to provide the required level of quality of service and experience, security, interactivity and reliability (initially developed by Precept Software in 1995, acquired by Cisco in 1998) Video-on-Demand http://en.wikipedia.org/wiki/Video_on_demand • Pay-Per-View (PPV) is a type of pay television service by which a subscriber of a service provider (cable TV, Satellite and Broadband Internet) can purchase events/shows/programs • In 2006, HBO generated 3.7 million PPV buys with $177 million in gross sales • In 2007, HBO sold 4.8 million PPV buys with $255 million in sales Video-on-Demand Issues Common problems/issues a VoD needs to address: • Load Distribution on Server • Media Content Management • Adapt to Dynamic Network Bandwidth • Decide on Buffer/Cache • Rate Control • Scalability & Cost Effectiveness • To provide Reliability & Availability Real Time Streaming Services http://en.wikipedia.org/wiki/Streaming_media http://en.wikipedia.org/wiki/HTTP_Live_Streaming http://en.wikipedia.org/wiki/Dynamic_Adaptive_Streaming_over_HTTP • Live Streaming, which refers to content delivered live over the Internet, requires a form of source media (e.g. a video camera), an encoder to digitize the content, a media publisher, and a content delivery network to distribute and deliver the content. • Progressive Download: the video