Multicast Tutorial

Description

MU LTIC AST Tut orialRedIRIS /Red.esO ctober 7t h, 2004AgendaIntr oductionM ulticast addr essingGroup M embership P rotocolPIM-S M / SSMM SDPM BGP2•Int roduction•M ulticast addressing•Group M embership P rotocol•PIM-SM / SSM•M SD P•M BGP3What is Multicasting?UnicastServerRouterMulticastServerRouter4Multicast UsesAny Applications with multiple receivers 1-to-ma ny or many-to-ma nyLi ve Video distributionSeminars, conferences, workshops ...Collaborative groupwaree- Learni ngPeriodic Data Delivery - "Push" technology stock quotes, sports scores, magazines, newspapers advertisementsServer/ Web- site replicationReducing N etwork/ Resource Ov erhead more efficient to establish multicast tree rather then multiple point-to-point linksResource Discovery5A bit of historyIn 1995 the fir st mcast netw ork w as bor n: M BoneDVM RP (D istance V ector Multicast R outing P rotocol) w as the protocol usedDVMRP subnetworks was interconnected through the unicast Internet infrastructure with tunnelsFlood and Prune technologyVery successful in academic circles6 A bit of historyProblem•DVMR P can’t scale to In ternet sizesDistance vector-based routing protocolPeriodic updates •Full table refresh every 60 secondsTable sizes•Internet > 40,000 prefixes at that momentScalability •Too many tunnels, hop- count till 32 hops, etc=> In 1997, a native pr otocol is developed, Protocol Independent M ulticast7The evolutionPIM ...

Informations

• Publié par: Nelaf
• Nombre de lectures: 39
• Langue: English

Extrait

40,000 prefixes at that momentScalability •Too many tunnels, hop- count till 32 hops, etc=> In 1997, a native pr otocol is developed, Protocol Independent M ulticast7The evolutionPIM ..." />

MULTICAST Tutorial

RedIRIS/Red.es

October 7th, 2004

Introduction

Agenda

Multicast addressing

Group Membership Protocol

PIM-SM / SSM

MSDP

MBGP

2

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Introduction

Multicast addressing

Group Membership Protocol

PIM-SM / SSM

MSDP

MBGP

3

Server

Server

What is Multicasting?

Rou

Rou

Unicast

Multicast

4

Multicast Uses

Any Applications with multiple receivers  1-to-many or many-to-many Live Video distribution  Seminars, conferences, workshops ....

Collaborative groupware e-Learning Periodic Data Delivery - "Push" technology stock quotes, sports scores, magazines, newspapers  stnemasetierdv Server/Web-site replication Reducing Network/Resource Overhead  more efficient to establish multicast tree rather then multiple point-to-point links Resource Discovery

5

A bit of history

In 1995 the first mcast network was born: MBone

DVMRP (Distance Vector Multicast Routing Protocol) was the protocol used

 was interconnected through the unicast InternetDVMRP subnetworks infrastructure with tunnels Flood and Prune technology  Very successful in academic circles

6

A bit of history

Problem

•DVMRP can’t scale to Internet sizes

 Distance vector-based routing protocol

 Periodic updates • Full table refreshevery 60 seconds

Table sizes • Internet > 40,000 prefixesatthat moment

 Scalability • Too many tunnels,hop-counttill32 hops,etc

=> In 1997, a native protocol is developed, Protocol Independent Multicast

7

The evolution

PIM Dense mode  Flood and Prune behavior very inefficient • Can cause problems in certainnetwork topologies  

Creates (S, G) state in EVERY router • Even when there are no receivers for   thetraffic

 Complex Assert mechanism • To determinewhichrouter   in a LAN will forward the traffic

No support for shared trees

8

The evolution

PIM Sparse mode Must configure a Rendezvous Point (RP) • Statically (oneveryRouter)

• Using Auto-RP or BSR (Routers learn RP automatically)

Very efficient • Uses Explicit Joinmodel

• Traffic only flows to whereit’sneeded

• Router stateonly created along flow paths

Scales better than dense mode • Worksforboth   sparsely or densely   populatednetworks

9

Source

Multicast Packets

PIM Dense Mode Overview

Initial Flooding

Receiver

(S, G) State created in everyrouter in the network!

10

Source

PIM Dense Mode Overview

Pruning Unwanted Traffic

Multicast Packets

Prune Messages

Receiver

11