Chapter 12 Multicasting Multicast Http netwk hannam ac

Chapter 12 Multicasting 과 Multicast 라우팅 프로토 콜 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 1

Chapter Outline 12. 1 Introduction 12. 2 Multicast Addresses 12. 3 IGMP 12. 4 Multicast Routing 12. 5 Routing Protocols 12. 6 MBONE Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 4

Topics Discussed in the Section ü Unicasting ü Multicasting ü Broadcasting Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 6

유니캐스팅(Unicasting) <하나의 송신지와 하나의 목적지간 통신 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 7

멀티캐스팅(Multicasting) Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 9

멀티캐스팅과 다중 유니캐스팅 비교 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 11

Topics Discussed in the Section ü Multicast Addresses in IPv 4 ü Selecting Multicast Addresses ü Delivery of Multicast Packets at Data Link Layer Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 15

Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 16

Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 17

Figure 12. 4 Mapping class D to Ethernet physical address Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 19

Note 이더넷 멀티캐스트 물리 주소의 범위는 다 음과 같다. 01: 00: 5 E: 00: 00에서 01: 00: 5 E: 7 F: FF 까지 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 20

터널링(Tunneling) Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 23

Topics Discussed in the Section ü Group Management ü IGMP Messages ü IGMP Protocol Applied to host ü IGMP Protocol Applied to Router ü Role of IGMP in Forwarding ü Variables and Timers ü Encapsulation ü Compatibility with other Versions Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 25

네트워크 계층에서 IGMP 위치 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 26

IGMP 메시지 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 28

멤버쉽 질의(Membership query) 메시지 형 식 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 29

질의(query) 메시지 형식 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 30

멥버쉽 보고(Membership report) 메시지 형 식 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 31

Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 32

소켓 상태(Socket state) Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 34

인터페이스 상태(Interface state) Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 37

변경 상태 보고 보내기 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 38

라우터 상태 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 39

일반 질의 보고와 관련된 상태의 변화 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 40

Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 42

최대 응답 시간 계산 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 43

Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 44

Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 45

Topics Discussed in the Section ü Optimal Routing: Shortest Path Trees Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 47

유니캐스트 라우팅에서 최단 경로 트리 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 49

Note In multicast routing, each involved router needs to construct a shortest path tree for each group. Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 50

송신자-기반 트리 접근 방법 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 52

그룹-공유(Group-shared) 트리 접근방법 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 54

Topics Discussed in the Section ü Multicast Link State Routing: MOSPF ü Multicast Distance Vector: DVMRP ü Core-Based Tree: CBT ü Protocol Independent Multicast: PIM Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 56

멀티캐스트 라우팅 분류 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 57

RPF(reverse path forwarding) Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 60

Note RPF는 플러딩 절차에서 루프를 제거한다. Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 61

RPF 문제점 Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 62

Figure 12. 24 Http: //netwk. hannam. ac. kr RPM versus RPB HANNAM UNIVERSITY 63

Note RPB creates a shortest path broadcast tree from the source to each destination. It guarantees that each destination receives one and only one copy of the packet. Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 64

Figure 12. 25 Http: //netwk. hannam. ac. kr RPF, RPB, and RPM HANNAM UNIVERSITY 65

Note RPM adds pruning and grafting to RPB to create a multicast shortest path tree that supports dynamic membership changes. Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 66

Figure 12. 26 Group-shared tree with rendezvous router Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 67

Figure 12. 27 Sending a multicast packet to the rendezvous router TCP/IP Protocol Suite Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 68

Note In CBT, the source sends the multicast packet (encapsulated in a unicast packet) to the core router. The core router decapsulates the packet and forwards it to all interested interfaces. Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 69

Note PIM-DM is used in a dense multicast environment, such as a LAN. Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 70

Note PIM-DM uses RPF and pruning/grafting strategies to handle multicasting. However, it is independent from the underlying unicast protocol. Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 71

Note PIM-SM is used in a sparse multicast environment such as a WAN. Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 72

Note PIM-SM is similar to CBT but uses a simpler procedure. Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 73

12 -6 MBONE Multimedia and real-time communication have increased the need for multicasting in the Internet. However, only a small fraction of Internet routers are multicast routers. Although this problem may be solved in the next few years by adding more and more multicast routers, there is another solution for this problem. The solution is tunneling. The multicast routers are seen as a group of routers on top of unicast routers. The multicast routers may not be connected directly, but they are connected logically. Http: //netwk. hannam. ac. kr HANNAM UNIVERSITY 74

Figure 12. 28 Http: //netwk. hannam. ac. kr Logical tunneling HANNAM UNIVERSITY 75

Figure 12. 29 Http: //netwk. hannam. ac. kr MBONE HANNAM UNIVERSITY 76