Routing and Multicast Protocol and Algorithm

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OUTLINE IGMP(Multicast Tree)DVMRPMOSPFPIM-DMPIM-SMCBT

InternetRouting(Routing Table)IPNetidNetid

(Distance-Vector) (Link-State) (Distance-Vector)

(Link-State)

IPIP 224.0.0.0~239.255.255.2551110Group ID

1110

Group ID(28)

32

IGMPIGMP(Internet Group Management Protocol) IGMPv1(RFC1112) IGMPv2(RFC2236)IGMPv3(RFC3376)

IGMPv1IGMPv1

VersionIGMPType0001= (Query)0002= (Report)Unused0ChecksumGroup Address0

Ver (4)

Type (4)

Unused (8)

Group Address (32)

Checksum (16)

32

(Multicast Tree)(Source Based Tree)DVMRPMOSPFPIM-DM(Group Shard tree)CBTPIM-SM

Source distribution treeReceiver 1ESourceNotation: (S, G) S = Source G = GroupCReceiver 2SRR

Shared distribution treeReceiver 1ESourceNotation: (*, G) * = all sources G = GroupCReceiver 2S1RRShared RootS2

Protocol typesDense mode protocolsassumes dense group membershipSource distribution tree DVMRP (Distance Vector Multicast Routing Protocol)MOSPF (Multicast OSPF)PIM-DM (Protocol Independent Multicast, Dense Mode)Sparse mode protocolassumes sparse group membershipShared distribution treeCBT (Core Base Tree)PIM-SM (Protocol Independent Multicast, Sparse Mode)

DVMRP (1) form a source tree by exchanging metricSourceReceiver 1SR1DFsource tree

DVMRP (2) broadcastSourceReceiver 1SR1DFsource treedatagram

DVMRP (3) pruneSourceReceiver 1SR1DFsource treedatagramIGMP DVMRP-Prune

DVMRP (4) X and Y prunedSourceReceiver 1SR1DFXYsource treedatagram

DVMRP (4) New memberSourceReceiver 1SR1DFXYsource treedatagramR2Receiver 2IGMP DVMRP-Graft

DVMRP (4) New branchSourceReceiver 1SR1DFXYsource treedatagramR2Receiver 2IGMP DVMRP-Graft

MOSPF MOSPF (Multicast Extensions to OSPF) OSPFOSPF

MOSPFMOSPF(Local group database)(shortest path tree)

MOSPFOSPFAreaAreaASArea

Each subnetwork consists of a designated router (DR), which is responsible for sending IGMP host membership queries and listens to the IGMP host membership reports.

CBT(Core-based tree,CBT) (Core router)(join message)

CBT

CBT

PIMPIM unicastPIM-SM(explicit join model)share treeroot(shortest path tree, SPT)

Dense-mode vs Sparse-modeDense-mode()request LANSparse-mode( WAN

PIM-DM(1)Initial flood of dataSourceReceiver 2Receiver 1SR1AR2BCDFGHIE

PIM-DM(2) C and D Assert to DetermineForwarder for the LAN, C Wins SourceReceiver 2Receiver 1SR1AR2BCDFGHIEIGMP PIM-Assert with its own IP address

PIM-DM(3)I, E, G send PruneH send Join to override Gs PruneSourceReceiver 2Receiver 1SR1AR2BCDFGHIEIGMP PIM-PruneIGMP PIM-Join

PIM-DM(4)I Gets PrunedEs Prune is Ignored (since R1 is a receiver)

SourceReceiver 2Receiver 1SR1AR2BCDFGHIE

PIM-DM(5)New Receiver, I send GraftSourceReceiver 2Receiver 1SR1AR2BCDFGHIEIGMP PIM-GraftReceiver 3R3

PIM-DM(6)new branchSourceReceiver 2Receiver 1SR1AR2BCDFGHIEIGMP PIM-GraftReceiver 3R3

PIM-SM SourceACDRPBReceiver R1

PIM-SM SourceACDRPBReceiver R1Source begins sendingA encapsulates data in registermessang and unicasts it to theRP.R1 begins receiving dataRegister

PIM-SM SourceACDRPBReceiver R1RP sends joins toward the sourcewhen it starts receiving data onthe source tree, a register stopis sent to A.JoinRegister Stop

PIM-SM SourceACDRPBReceiver R1Receiver R2 joins groupD sends join towards RPC sends join towards RPR2 receives data on RP treeJoinReceiver R2Join

PIM-SM SourceACDRPBReceiver R1D sends (S,G) join towards sourceA begins forwarding. SPT tree existsD sends (S,G) RP Bit prune towards RPReceiver R2(S,G) Join(S,G)RP prune

PIM-SM SourceACDRPBReceiver R1Receiver R2R2 is receiving data on source tree,R1 is receiving data on shared (RP) tree

PIM-SM SourceACDRPBReceiver R2R1 sends IGMP leaveRP stops forwarding on R1 LANRP sends (S,G) prune towards source

Multicast In Wireless Mobile Environments

IntroductionWireless Network CategoriesIntroduce the issues involved in providing multicast in a mobile environmentDiscuss details of proposed multicast routing protocols

Wireless Network CategoriesInfrastructure Wireless: base station network is connected to the wired Internet.Ad hoc Wireless:wireless nodes communicate directly with one another.

Wireless LANs(a) Infrastructure Wireless(b) Ad hoc Wireless

Issues In Mobile EnvironmentsMulticast Forwarding AlgorithmA source-based protocol like DVMRP ,DVMRP forwards multicast packets only if it receives them on the correct interfacewhen mobile host (MH) moves to a new domain , its interface to the multicast router changes , resulting in the packets being dropped

Issues In Mobile EnvironmentsDense or Sparse Model ProtocolThe dense mode protocols are useful if there are a lot of users and bandwidth availabilitiy is not a problem, whereas sparse mode protocols are meant for widely distributed users with limited bandwidth.

Issues In Mobile EnvironmentsQos ProvisioningQuality of service (QoS)-based wireless multicasting is an open issueIn this section we first describe Mobile-IP based multicasting protocols

Proposals for Multicast over MIPRemote SubscriptionIt is the simplest way of providing multicast through Mobile IP.In remote subscription an MH re-subscribe to the multicast group each time it moves to a new foreign network.

Remote Subscription

Out-of-synch problem

Compare

Proposals for Multicast over MIPBidirectional TunnelingIn this scheme MHs send and receive multicast packets by way of their home agents (HAs), using unicast Mobile IP tunnels from their HAs.

Bidirectional Tunneling

Tunnel convergence

Compare

Multicast support using Mobile IPMulticast support using Mobile IP (MoM)MoM is based on bidirectional tunnelingMoM selected HA among the given set of HA is called designated multicast service provider (DMSP)

MoM

DMSP selectClassify 1.Agent based2.Count-based3.Proximity-based4.Random-based

Compare

RBMoMRange-Based Mobile Multicast (RBMoM)RBMoM provides a trade-off between the shortest delivery path and the frequency of multicast tree reconfigurationIt selects a router called a multicast HA(MHA)Every MH can have only one MHAMHA(Multicast HA) is responsible for tunneling multicast data to foreign networks

Select the new MHA

Compare

Proposals for Multicast over MIPMulticast for Mobility Protocols (MMP)MMP uses a sparse mode multicast routing protocol Core Base Trees (CBT) to handle the movement of mobile nodes within a foreign network.This scheme uses a shared-tree, to and from a centre point called the core of the network.MMP relies on Mobile IP Agent Discovery procedure in order for mobile hosts to discover relevant Mobility Agents and obtain a multicast care-of-address.

MMP1.BS transmit periodic beacons with Agent Advertisement messages 2.MN transmits a Registration Request to the base station 3.BS will send a Join request to the Core and create a permanent group 4.MN moves to another cell, it will initiate handoff when it receives a stronger beacon

MobiCastMobiCast is designed for an internetwork environment with small wireless cells, with many cells grouped together and served by domain FAs (DFAs).

MobiCastWHEN MN JOIN GLOUP X1.MN send IGMP message to DFA2.DFA replace MN join X3. Construct multicast group Y and all APs join group Y

Reliable Wireless Multicast ProtocolsReliable Multicast Data Distribution Protocol (RMDP):Uses Forward Error Correction (FEC) and Automatic Retransmission reQuest (ARQ) information to provide reliable transfer. Redundant information is inserted into the FEC, often enabling a receiver to reconstruct the original packet. In the event that such information is not enough, an ARQ is sent to the multicast source which in turn, multicasts the requested packet to all receivers.

Reliable Wireless Multicast ProtocolsRM2RM2 is a reliable multicast protocol that can be used for both wired and wireless environments.RM2 is a hierarchical protocol that divides a multicast tree into subtrees where subcasting within these smaller regions is applied using a tree of retransmission servers (RSs)

Reliable Wireless Multicast ProtocolsRS having a retransmission subcast address shared by its members and which may be dynamically configured using the IETFs Multicast Address Dynamic Client Allocation Protocol (MADCAP).The receivers are required to send negative acknowledgments (NACKs), pointing out the packets to be retransmitted.

RM2

compare

ConclusionThis article is an attempt to give an overview of current research in wired and wireless multicast field and show that this area is rapidly growing and evolving.Future directions in wireless multicast need to consider QoS, security, and so on.

ENDTHANK YOU!

dense-mode requestso if setting dense-modemulticast forwarding interface traffic prune traffic

sparse-mode RP S request reciver request RP traffic forwarding