TELECOM ITALIA GROUP Ongoing Activities Report BT London, Feb 15, 2011

Topics ► Application-Layer Traffic Optimization ► Video Traffic Optimization ► AOB

BT Ongoing Activities Report Application-Layer Traffic Optimization

BT Ongoing Activities Report Application-Layer Traffic Optimization in IETF ► Protocol for exporting network topology information ► Assist application in selecting the hosts they can connect to ► Peer-to-peer ► File sharing: find close and well connected peers ► VoIP: find close and fast relays ► P2P Streaming: find close, fast and well connected stream sources ► CDN: find close cache servers ► Protocol ~80% done ► Discussion on REST-like/REST-full approach ► Security ► Protocol interoperability event in July ► Demo show in March

BT Ongoing Activities Report ALTO Protocol – Maps 55

BT Ongoing Activities Report ALTO Protocol – Ranking Service 6

BT Ongoing Activities Report ALTO Protocol – Maps and Ranking Combined 7

BT Ongoing Activities Report Opensource ALTO Client (for Vuze) Design Goals ► Provide a knob for influencing peer selection ► Peer connect ► Optimistic unchoke ► Provide a framework for collecting statistics ► Extensibility ► Different logics/protocols ► Different stats collection strategies 8

BT Ongoing Activities Report Traffic Localization Study (from Telefonica) ► “Deep Diving into BitTorrent Locality”, R. Cuevas et al., INFOCOM 2011 ► Research activity going on since 2008 ► Extended study on 100K torrents, 3.5M peers, 9K ASes ► Experimental validation ► Italy ≠ Spain ≠ UK ► Inherent language localization ► Uplinks ► Proposed localization model ► Traffic savings at locality/QoS breakthrough point varies between 10% and 35% 9

BT Ongoing Activities Report Video Traffic Optimization 10

BT Ongoing Activities Report HTTP Video Streaming Optimization ► HTTP-based streaming ► Youtube and the like, Apple HTTP Live Streaming… ► ~40% (steadily growing) of total mobile traffic ► Optimization Strategies ► Smart buffering ► Compression ► Re-encoding, transcoding, transrating, resizing ► Dynamic bitrate adaptation ► May make sense on mobile ► 3G dongle and smartphones ► Resources for compression cheaper than radio link 11

BT Ongoing Activities Report Internal Trial – Three solutions ► Technical evaluation ► Optimization (compression, smart buffering…) ► Codecs support ► Content detection ► Transparency ► Caching ► Configurability ► Quality evaluation ► Focus group ► Outcome ► Technology roughly mature ► 30% to 50% reduction in video traffic 12

BT Ongoing Activities Report Savings Estimation 13 WARNING: what follows is a simplified model for savings estimation elaborated over the eight weeks trial period. It is based on rough assumptions that, to the least, need to be double checked with real data

BT Ongoing Activities Report Savings Estimation – Assumptions 14 DefinitionBitrate Acceptable Compression Frequency (3G dongles) Low Resolution (240p) 360x Kbps10%15% Mid Resolution (360p) 480x Kbps40%80% High Resolution (720p) 1280x Kbps60%5%

BT Ongoing Activities Report Savings Estimation – Compression ► Average bitrate: ► 200 * 15% * 80% * 5% = 770 Kbps ► Average bitrate after compression: ► 200 * 15% * 90% * 80% * 60% * 5% * 40% = 451 Kbps ► Savings on video traffic due to compression: ► / 770 = ~40% 15

BT Ongoing Activities Report Savings Estimation – Smart Buffering ► More assumptions ► Users watching a video switch after 20 seconds on average ► Available bandwidth on average: 900 Kbps ► Average video bitrate: 770 Kbps (derived above) ► Data downloaded for each video: ► 20 sec * 900 Kbps = 2.1 MB ► Data downloaded for each video with smart buffering: ► 20 sec * 770 Kbps = 1.8 MB ► Savings on video traffic due to smart buffering: ► / 2.1 = ~14% 16

BT Ongoing Activities Report Savings Estimation – Overall ► Data downloaded for each video: ► 20 sec * 900 Kbps = 2.1 MB ► Data downloaded for each compressed video with smart buffering: ► 20 sec * 451 Kbps = 1.1 MB ► Total savings on video traffic: ► 1 – 1.1 / 2.1 = ~47% Note Well: Savings are referred only to video traffic delivered by HTTP streaming (e.g. YouTube, Facebook…), reportedly accounting for about 25% - 50% of the total Internet traffic 17

BT Ongoing Activities Report Savings Estimation – Simulations 18 Low Res Frequency Mid Res Frequency High Res Frequency Available Bandwidth Watch Time Savings on Video 15%80%5%900 Kbps20 sec50% 20%75%5%800 Kbps10 sec46% 30%65%5%500 Kbps10 sec19% 10%70%20%1200 Kbps30 sec57%

BT Ongoing Activities Report Possible Issues ► Legal ► Net neutrality ► Agreements requirements ► Complexity/Reliability ► Technology evolution ► Protocols, codecs, encryption ► Popularity shift 19

BT Ongoing Activities Report AOB 20

BT Ongoing Activities Report CDN Interoperability ► BoF in Prague ► Interface for CDN interwork ► Request routing ► Metadata exchange ► Logging ► Orthogonal to ALTO ► CDN usage for ALTO to pick the closest cache 21

BT Ongoing Activities Report SIP-XMPP Coexistence ► Combined SIP-based VoIP and XMPP-based presence ► XMPP has wider adoption than SIP SIMPLE ► PSTN interoperability is based on SIP ► SIXPAC WG proposed last year ► Virtual PBX for SME 22

BT Ongoing Activities Report Other IETF Work ► RTP extension for audio levels in conference calls ► P2PRG ► ISDN UUI in SIP (booooring!) 23