P2P and the Future Internet. Pablo Rodriguez Telefonica Research, Barcelona

Transcription

1 P2P and the Future Internet Pablo Rodriguez Telefonica Research, Barcelona

2 The Future Internet Social Networks that mimic personal relationships Personalized TV, Video Mash-Ups Recommendation and Aggregation Engines My Reputation, how people see my company? but let s talk about the Future Internet Network 2

3 P2P is everywhere... P2P telephony: Skype (or how to deal with NATs) P2P TV: Joost is about to realise the dream of ubiquitous/personalized TV. P2P File Delivery: bittorrent.com scales large file dissemination without having to wait for IP Multicast P2P Data Syncing: backs up your data and keeps it in sync across all your computers, e.g. Groove 3

4 Why? Users took matters in their hands Tired of waiting for the network IP Multicast Good Naming Protocol Anycasting End2end connectivity No need to change all routers in the world, not need to make an agreement with every single ISP 4

5 P2P and the Future Internet 1. Re-Thinking the Internet to Distribute Content 2. Swarming in Routing Protocols 5

6 I.- Re-Thinking the Internet to Distribute Content Internet was designed for host-to-host communication but is mainly used for data access - get me this file... rather than contact this computer It does not matter where content comes from Data distribution unnecessarily hard If content location changes, pointers are broken P2P used overlay naming schemes Can we re-design the Internet to better support content distribution? 6

7 II.- P2P Swarming in Routing Protocols Packet Networks: Time Multiplexing Reuse the same channel across time P2P: Space Multiplexing Leverage unused resources across nodes in the network Space Diversity => Can we integrate P2P swarming concepts with routing? 7

8 Wireless Mesh Networks New networking paradigm Alternative to Infrastructure based solutions Easy to deploy: Cheap hardware No infrastructure New Applications: Community networks Increase broadband penetration. Wireless office No cabling, Self configured 8

9 Routing algorithms and Swarming Mesh Routing protocols have mostly focused on finding the best path from S->D However, Multiple paths between each source and destination pair exist: Exploit diversity Increase throughput Decrease packet loss rates How can we use the multiple paths efficiently? Benefit of using many paths. # of paths to use. Fair allocation of resources. Congestion control => Ideas from network coding and multipath congestion control help. 9

10 Multipath routing Destination A, B, C, D Scheduling of transmissions is difficult: Coordination between nodes Have to know the capacities along each path A B D A B C A B C A B D A B C B D Instead, use network coding Randomize information B D Source Data to send: A, B, C, D Observe the broadcast nature of the channel 10

11 Performance on a realistic topology: Roofnet Wireless mesh network in Boston, MA: -37 residential nodes -Highly variable wireless links Significant performance improvements for many flows Multiplath Code Casting (MC2): Work with Christos Gkantsidis, Peter Key, and Bozidar Radunovic (MSRC), Wenjun Hu (Cambridge University), and Steluta Gheorgiu (Telefonica) 11

12 Lots of open issues Broadcast or Unicast in promiscuous mode? Path finding and selection Optimal set of paths Coding/Decoding Buffer management Error control Hop-by-hop vs end-to-end action Rate control Assigns coding rate between paths Performance of higher-level protocols E.g. UDP, TCP, streaming, low-latency (gaming). 12

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