iLab2 Introduction to IP - Multicast Daniel Raumer - PowerPoint PPT Presentation

Lehrstuhl Netzarchitekturen und Netzdienste Institut für Informatik Technische Universität München iLab2 – Introduction to IP - Multicast Daniel Raumer raumer@net.in.tum.de

“What is he talking about?”  Multicast?  Motivation  Layer-3 (IP) Multicast  Wrap-Up iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 2

Multicast  Concept Unicast Broadcast Multicast  Anycast? Geocast?  Multicast on layer n can be realized by unicast connections on layer n-1  On which layer?  Physical layer on a shared medium  IP Layer to avoid traffic  Application layer e.g. to simplify communication in online games iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 3

Multicast – Why? iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 4

Multicast – Why? iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 5

Multicast – Who? iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 6

Multicast – Who?  During champions league final in 2012  no live TV broadcast in Italy  Traffic at TOPIX (an Italian IXP) iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 7

Multicast – Who?  Football Worldcup 2010  Video streams with1.5 MBit/s per User - and this is not hd ;-)  Continuously for up to 2 hours  180 000 concurrent streams in Germany  270 000 MBit/s or about 270 GBit/s  Provider Networks 200 User 300 MBit/s 300 MBit/s 1000 User 2550 MBit/s 1500 MBit/s 2250 MBit/s 2550 MBit/s 750 MBit/s 500 User iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 8

2011 Example     iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 9

2011 Example     iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 10

2011 Example     iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 11

2011 Example     iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 12

2011 Example  Vodafone Network: + 20,5 % Data Traffic    iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 13

2011 Example  Vodafone Network: + 20,5 % Data Traffic  Youtube Lifestream: 400 000 000 Viewers   iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 14

2011 Example  Vodafone Network: + 20,5 % Data Traffic  Youtube Lifestream: 400 000 000 Viewers  Obama Inauguration 70 000 000 Viewers  iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 15

2011 Example  Vodafone Network: + 20,5 % Data Traffic  Youtube Lifestream: 400 000 000 Viewers  Obama Inauguration 70 000 000 Viewers  Akamai: 1 600 000 concurrent streans iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 16

2011 Example  Vodafone Network: + 20,5 % Data Traffic  Youtube Lifestream: 400 000 000 Viewers  Obama Inauguration 70 000 000 Viewers  Akamai: 1 600 000 concurrent streans iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 17

Multicast – And how does it work?  Back in the old days of the Internet  1985 (2 years after switch day) -RFC 966 - A Multicast Extension to the Internet Protocol • Paper Cheriton et al: “The extensive use of local networks is beginning to drive requirements for internet facilities…”  1986 National Science Foundation: Largest Backbone: 56 kbit/s  1989 - RFC 1112 - Host Extensions for IP Multicasting 200 User 1.5 MBit/s 1.5 MBit/s 1000 User 1.5 MBit/s 1.5 MBit/s 1.5 MBit/s 1.5 MBit/s 1.5 MBit/s 500 User Other application scenarios?  iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 18

Multicast – Addressing  All Class D addresses are multicast addresses 1 1 1 0 multicast group id Class D 28 bits Class From To D 224.0.0.0 239.255.255.255  Address space is managed by IANA  Divided into different blocks with certain purposes Examples: 224.0.0.1 addresses all hosts on the same network segment. 224.0.0.2 addresses all routers on the same network segment. The Cisco multicast router AUTO-RP-ANNOUNCE address is used by RP 224.0.1.39 mapping agents to listen for candidate announcements. iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 19

Multicast – joining and leaving a multicast group  Internet Group Management Protocol (IGMP)  IGMPv1 (RFC 1112)  IGMPv2 (RFC 2236) “Join” to the DR “Prune” to the DR  IGMPv3 (RFC 3376, RFC 4604) 0 MBit/s 0 Users 1.5 MBit/s 200 User 0 MBit/s 1.5 MBit/s 1.5 MBit/s 1.5 MBit/s 1000 User 1.5 MBit/s 1.5 MBit/s 1.5 MBit/s 500 User 1.5 MBit/s 300 User  Same but different for IPv6  Multicast Listener Discovery (MLD)  MLD is part of ICMPv6 instead of using a separate protocol.  MLDv1 ~ IGMPv2, MLDv2 ~ IGMPv3 (RFC 3810, RFC 4604) iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 20

Multicast – different modes  Protocol Independent Multicast } Known from the Prelab  Sparse Mode (SM)  Dense Mode (DM)  Bidirectional PIM (Bi-Dir)  Source-Specific Multicast (SSM) PIM-DM messages Type PIM-DM PIM-SM }   Hello 0 to determine the DR  Register 1  Register-Stop 2 for group management   Join/Prune 3  Bootstrap 4   Assert 5  Graft 6  Graft-Ack 7  Candidate-RP- 8 Advertisement iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 21

Multicast – different modes  Source Trees  One source of traffic  GroupID and SourceID required for joining the group  Shared Trees  Different sources of traffic  Distribution tree is shared among all senders  Only GroupID is required to join a group RP? Rendezvous Point (RP)  RP can be configured statically  …or via mechanisms like Auto -RP or Bootstrap Router (BSR) iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 22

Wrap-Up  IP- Multicast  used mainly in enterprise IP-networks  Why?  delays complexity to the routers  Many Protocols, mechanisms & related buzzwords ;-) PIM -DM PIM-SM IGMPv3 PIM-SSM ICMP & MLD IGMPv1 IGMP v2 … and many others & all belonging RFC‘s  One last question: “Why is PIM called ‘protocol independent’ ?” … at least It‘s a small lab - I wish you fun doing it iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 23

The End iLab2 – Introduction to IP-Multicast – Daniel Raumer – 2013-11-14 24