Introduction to IP multicast routing

Introduction to IP multicast routing

     POSTECH Networking and Distributed Systems Lab. - 2 -    ! "#  $%&  !'! %  ()*$+,-./  0001.&234+   ! 5 '!$"6!%)6    000$"6,%&"&&  POSTECH Networking and Distributed Systems Lab. - 3 -     %     5   5   POSTECH Networking and Distributed Systems Lab. - 4 -   !+6 1.  $  %" 7  # POSTECH Networking and Distributed Systems Lab. - 5 -   #6  -+.  (*3  !  "3  1.34+  "  "" POSTECH Networking and Distributed Systems Lab. - 6 -  8  $ 5  - ! $ 5  - ! POSTECH Networking and Distributed Systems Lab. - 7 -     6  +69  85  :;<======  :;6  :; >9?6@ POSTECH Networking and Distributed Systems Lab. - 8 -     A  $%+ POSTECH Networking and Distributed Systems Lab. - 9 -   6>@                                  POSTECH Networking and Distributed Systems Lab. - 10 -    *6  (.  (.6  $+6  $6  (.6  $""+6  4 [...]... lo o d i i n g F i r s t F lo o d i n g F o u rth F lo o d iin g POSTECH Networking and Distributed Systems Lab - 24 - Distance-Vector Multicast Routing Protocol Intra-Domain Protocol of Dense Mode  Construct source-based multicast tree  Depends on RIP, the Unicast protocol  Flood & Prune for construct tree by the first packet  POSTECH Networking and Distributed Systems Lab - 25 - Constructing DVMRP... Exist at IP module of host  IGMP messages       Enables a MR to keep track of group Host membership query Host membership reply Join-group report Leave-group report POSTECH Networking and Distributed Systems Lab - 21 - Contents Intra Domain MR Protocol RPF  DVMRP  MOSPF  CBT  PIM-DB  PIM-SM  POSTECH Networking and Distributed Systems Lab - 22 - Reverse Path Forwarding A method to Find shortest... to Implement  Incrementally deployable POSTECH Networking and Distributed Systems Lab - 18 - Classes of MR Protocols  Host to Router   Intra-Domain   IGMP DVMRP, MOSPF, PIM-DM/SM, MIP Inter-Domain  YAM, QosMIC, BGMP, PTMR-, EXPRESS POSTECH Networking and Distributed Systems Lab - 19 - Example of MR protocols POSTECH Networking and Distributed Systems Lab - 20 - Internet Group Management Protocol... Group shared multicast tree  STP is a NP-complete problem  Steiner node   A MR tree nodes which do not belongs to multicast group(e.g.:node D, E in fig) POSTECH Networking and Distributed Systems Lab - 16 - Two Steiner Trees A ll R o u te POSTECH Networking and Distributed Systems Lab 1 s t S te in e r T r e e R o u te 2 n d S te in e r T re e R o u te - 17 - Properties of Good MR Protocols  Efficiency... packet delivery costs  No routing loops  Support incremental deployment   Use DVMRP Tunnel for inter domain Easy to implement  Low computational complexity  POSTECH Networking and Distributed Systems Lab - 28 - Drawbacks of DVMRP Big memory usage  Poor scalability  Waste bandwidth  Hard to Mange Group(flooding)  POSTECH Networking and Distributed Systems Lab - 29 - Multicast Open Shortest Path... to Mange Group(flooding)  POSTECH Networking and Distributed Systems Lab - 29 - Multicast Open Shortest Path First Intra-Domain Protocol of Dense Mode  Depends on OSPF, Unicast Protocol  Tree is built on demand by First Packet  Every routers knows complete routing topology  Make Source-based Tree  Dijkstra Algorithm for computing Paths  POSTECH Networking and Distributed Systems Lab - 30 - Constructing... MOSPF  CBT  PIM-DB  PIM-SM  POSTECH Networking and Distributed Systems Lab - 22 - Reverse Path Forwarding A method to Find shortest path from one source to many receivers  flood & prune  Uses unicast routing table  Employed in many MR protocol   DVMRP, MOSPF, PIM-DM, etc POSTECH Networking and Distributed Systems Lab - 23 - Steps of RPF MR3 MR2 MR1 MR6 MR4 MR5 MR7 MR8 MR9 A ll R o u te S e... computation  Poor Scalability  Not support incremental deployment    No tunnels nor any feature for support it Hard to Mange Group(flooding) POSTECH Networking and Distributed Systems Lab - 34 - Core Based Trees Intra-Domain Protocol of Sparse Mode  Uses only one tree per group  To Overcome the scalability  Do not use RPF  POSTECH Networking and Distributed Systems Lab - 35 - Joining a CBT Group... Heavy control message Hard to manage group Dense mode  DVMRP,MOSPF, PIM-DM  POSTECH Networking and Distributed Systems Lab - 12 - Source Based Tree A ll R o u te POSTECH Networking and Distributed Systems Lab M u ltic a s tin g T re e R o u te - 13 - Group Shared Tree A Tree Required per Group  Center based Tree Constructing       Scalable Light control message Easy to Manage group Traffic Concentration