P2P is everywhere... P2P Telephony: Skype (or how to deal with NATs)Skype P2P TV: Joost is about to realize the dream of ubiquitous/personalized TV.Joost P2P File Delivery: bittorrent.com scales large file dissemination without having to wait for IP Multicastbittorrent.com P2P Data Syncing: backs up your data and keeps it in sync across all your computers, e.g. GrooveGroove 3
Why…? We got tired of waiting for the network to support various things: E2E IP Multicast Content-Based Naming Protocol Anycasting End2end reachability Quickly experiment new ideas: no need to change all routers in the world or make an agreement with every single ISP in the world 4
P2P Swarming & Routing Protocols Time Multiplexing Packet Networks: Time Multiplexing Reuse the same channel across time Space Multiplexing P2P: Space Multiplexing Leverage unused resources across nodes in the network 5 Can we integrate P2P swarming concepts with routing and use network coding to build a universal swarm?
13 P2P and ISPs In one sense, ISPs of course love it… Because a lot more customers subscribe for broadband Though they must be kicking themselves for not charging for volume during the P2P growth boom!
14 Ultimately there are some fundamentals here P2P protocols allow end hosts to pretty much fill their access bandwidth constantly Total access bandwidth could exceed total backbone bandwidth by (very roughly) one or two orders of magnitude In other words, the Internet is (or easily could be) over- subscribed.
15 Difficulties Increased traffic volume without increased revenue Users got a lot of value out of P2P but nobody got paid extra for it! Eventually, ISPs will reach customer saturation, and then… Conflicts between Overlay and Underlay P2P topologies are not aware of the ISPs economics. This makes P2P traffic to be routed over expensive transit links.
19 Solutions Filter P2P Traffic Reduces access revenue Add caches Expensive to maintain, legal problems Keep traffic within ISP Establish new ISP relationships Flattens the Internet Redirect traffic to less expensive peering points
P2P traffic could go through unwanted links 20 SPRINT/LEVEL3 Access ISP Telefonica Backbone Tel Spain Tel Brasil Transit ISP Backbone Access ISPs Transit ($$$) P2P Other Backbone (II) Peering ($$) Other Backbone (I) Peering ($)
Can ISPs take advantage of clients within? Percentage of Torrents 21 Percentage of local Peers -Two modes: One for all local swarms Another for all foreign swarms
Potential for locality for Telefonica -More than 50% of traffic could stay within
24 Several Content providers are using legal P2P networks to reduce their distribution cost to zero The most popular case is the BBC. However, they are basically pushing the distribution cost to the ISP… Content Providers are moving fast…
BBC iMP – Legal P2P Distribution Content Trial Sep 05 Sky announced competing offering Every major broadcaster evaluating P2P
30 Why does it makes sense? ISPs can control the user experience and how the p2p traffic flows in his network ISPs can engage in the content distribution cycle Removes content distribution hassle from Content Providers Integrates well with existing IPTV solutions -
31 Massive Data Centers NOW data centers P2P Capital intensive Huge energy consumption Far from the end users Uncoordinated Only statistical QoS Poor use of resources Random topologies Simplistic scheduling I am just a process I have steel walls a huge gap
32 Distributed Nano data centers using set-top-boxes power & cooling for free decent CPU & storage predictable behavior central control A set-top-box provides … all we need to do is organize them a bit!
One Real Example: Imagenio P2P home gateway STB PC TV DSLAM customer premise TV head end ISP IP Multicast Internet phone 33 Internet (1 Mb/s) VoIP IPTV (5 Mb/s) 1-2 channels Last mile (6 Mb/s) 1Gb/s 6Mb/s Joined work with Cambridge Univ and KAIST
P2P for Past Scenes: VoD Server Savings 34 (no p2p) (p2p)
Conclusions P2P has provided a great opportunity to deploy new applications There is a lot of potential to integrate P2P swarming solutions in routing (and use network coding to avoid scheduling problems) However, the economics are still not clear and interactions with ISPs are non-optimal. P2P systems will need to adapt. Telco-Managed P2P systems provide lots of opportunities to scale IP-TV services and a stable P2P ecosystem 35