1. Study of the Relationship between Peer to Peer Systems and IP Multicasting From IEEE Communication Magazine January 2003 學號 :M9129017 姓名 : 邱 秀 純

2. 2003-05-28 Outline Introduction Feature of P2P system Problem of P2P system Requirements for IP Multicast over P2P systems Evaluation of applying IP Multicasting to P2P system Conclusion

3. 2003-05-28 Introduction Peer to Peer (P2P)System? Involve a number of directly connected “ peers” exchanging various types of information among themselves The Problem? Applications based on P2P systems generate a lot of traffic and Require not only the resources of every peer IP Multicasting The Style of IP Multicasting is that the multicast routers make copies of incoming data and distribute them to a multicast tree IP Multicasting will help to reduce the load on streaming servers and network traffic because streaming servers only have to send data once

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5. Feature of P2P system P2P system have two phase:  Discovery phase : A peer tries to find another peer that has what it wants  Delivery phase : direct communication is performed with the discovered peer Two type of P2P Systems Hybrid P2P system: has a central sever with a set of indexes, and each peer asks it during the discovery phase Pure P2P system : lack a central server

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7. Problem of P2P system

8. 2003-05-28 Problem of P2P system P2P systems essentially require a broadcast mechanism, and we should usually used a series of unicast or broadcast packets Problem: Continuous unicast packets may need the CPU power and bandwidth of peers and all of the network resource Using Broadcast packers raises concerns about wasting various resources and security because all peers receive them whether or not they want to

9. 2003-05-28 Solve by using IP Multicast To reduce the number of irrelevant packets Decrease the need to use peers’ resources

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11. Requirements for IP Multicast over P2P systems Live stream service and P2P Contents sender Opportunities to update member list Types of traffic flow Range of propagation The main differences Contents sender can join or leave dynamically The number of contents senders is the same as the number of contents receivers

12. 2003-05-28 Routing protocol(1) PIM is IP routing protocol-independent and can leverage whichever unicast routing protocols are used to populate the unicast routing table PIM uses this unicast routing information to perform the multicast forwarding function PIM uses the unicast routing table to perform the RPF check function instead of building up a completely independent multicast routing table PIM does not send and receive routing updates between routers. 參考網頁 http://www.cisco.com/univercd/cc/td/doc/cisintwk/intsolns/mcst_sol/ mcst_ovr.htm#xtocid25

13. 2003-05-28 Routing protocol(2) PIM:compose multicast trees using routing tables made by an arbitrary unicast routing PIM-SM : the only terminals that receive multicast messages are ones that obviously belong to the multicast group because the sent “IGMP” join messages PIM-SSM is source-specific protocol, and the contents receiver can specify the addresses of desired sources in the IGMP join message PIM-SSM is considered a suitable protocol for one to many live streaming services

14. 2003-05-28 Routing protocol(3)

15. 2003-05-28 Routing protocol(4) PIM-SM: Send IGMP message to join/leave group PIM-SSM: There is a multicast tree originating form each content server, there are N multicast trees if the number of peers in N A peer that wants to join this group must 1) send an IGMP join message to all multicast trees with the sender’s address 2) get all other peers to send it an IGMP join message with its own address so that it can create a new multicast tree Leave group, a peer sends an announces it departure Sequence for joining groups

16. 2003-05-28 Routing protocol(5)

17. 2003-05-28 Routing protocol(6) Achieve network load balancing: PIM-SM: distributing RPs PIM-SSM: unicast routing protocol The most significant difference is PIM-SSM’s complex group-joining procedure The PIM-SM is better than PIM-SSM for P2P system Comparison of PIM-SM and PIM-SSM

18. 2003-05-28 Evaluation of applying IP Multicasting to P2P system

19. 2003-05-28 Conclusion Problem: A much faster backbone network will be required Solution: We showed that almost every application can be improved by our proposal We discussed which routing protocol is suitable for P2P system Other issues Techniques : clarify the sequences for joining/leaving groups and the effect of the RP’s location on traffic characteristics Network management : the multicast address allocation and traffic control method for the entire network