1. 1 ISP-Aided Neighbor Selection for P2P Systems Vinay Aggarwal vinay@net.t-labs.tu-berlin.de vinay@net.t-labs.tu-berlin.de Anja Feldmann, Obi Akonjang, Christian Scheideler (TUM) Deutsche Telekom Laboratories TU Berlin, Germany

2. 2 P2P traffic r >50% of Internet traffic m Examples: Bittorrent, eDonkey, Skype, GoogleTalk… Internet traffic distribution 2007 (Germany) Source: ipoque GmbH (Nov 2007)

3. 3 P2P from an ISPs view r Good: m P2P applications fill a void m P2P applications are easy to develop and deploy m P2P applications spur broadband demand r Bad: m P2P systems form overlays at application layer m Routing layer functionality duplicated at app layer m P2P topology agnostic of underlay performance loss m Traffic engineering difficult with P2P traffic r ISPs are in a dilemma

4. 4 Solution: ISP-P2P cooperation r Insight: ISP knows its network m Node: bandwidth, geographical location, service class m Routing: policy, OSPF/BGP metrics, distance to peers

5. 5 Solution: ISP-P2P cooperation r Insight: ISP knows its network m Node: bandwidth, geographical location, service class m Routing: policy, OSPF/BGP metrics, distance to peers r Our idea: m ISPs: offer oracle that provides network distance info m P2P: use oracle to build P2P neighborhoods

6. 6 Solution: ISP-P2P cooperation r Insight: ISP knows its network m Node: bandwidth, geographical location, service class m Routing: policy, OSPF/BGP metrics, distance to peers r Our idea: m ISPs: offer oracle that provides network distance info m P2P: use oracle to build P2P neighborhoods r Oracle concept m Service of AS / ISP m Input: list of possible dst IPs m Ouput: ranked list of dst IPs E.g. according to distances between src IP and dst IPs

7. 7 Oracle service Oracle-based peer selection for topology and content exchange

8. 8 Oracle service (example)

9. 9 Oracle service (2.) Oracle-based peer selection localizes topology and traffic

10. 10 ISP-P2P cooperation r ISP-aided optimal P2P neighbour selection m Simple and general solution, open for all overlays m Run as Web server or UDP service at known location Similar to bind (DNS)? r Benefits: P2P m No need to measure path characteristics m Easy to avoid bottlenecks => better performance r Benefits: ISPs m Regains control over traffic m Less traffic leaving network => cost savings m Customer service improvement

11. 11 ISP/P2P concerns r Network info m ISP ranking algorithm confidential m Output is ranked list or classification, actual statistics not revealed m List can be anonymized and dynamically altered m Network info revealed is already possible to reverse-engineer using available tools r Legal Issues m No caching of content at ISP m Oracle is a peer mapping service => consulting oracle does not imply participation in file-sharing