© 2004 Cisco Systems, Inc. All rights reserved

1© 2004 Cisco Systems, Inc. All rights reserved.

Rich Gore

Cisco@Work Case Study: IP Multicast: A Scalable Transport for Network-Based Broadcast

Cisco Information Technology

October 8, 2003

mailto:Cisco@Work

222© 2003 Cisco Systems, Inc. All rights reserved.Presentation_ID

Overview

• Challenge: One-to-many real-time traffic needs

Corporate meetings and videos

• Solution: Multicast – ASM and SSM

Efficient one-to-many transport

Recently upgraded network to SSM

• Results: Multicast and SSM is a success

Stable and usable within the network

• Next Steps: New applications

Music on Hold and Info Cast


Challenge: One-to-Many Real-Time Traffic Needs

• Corporate videos of meetings and training saved travel money, but were expensive

Sending video tapes to remote sites – too much delay

Setting up switched digital circuits – too expensive

• Cisco® IP/TV® can send video across corporate WAN, but …

• Corporate WAN could not manage thousands of video streams simultaneously

Server

Multiple Streams Without IP Multicast

Router

Multiple Data Streams

Receivers


Solution: Multicast – ASM and SSM

• Multicast ASM (Any Source Multicast) – in use for 4 years

Requires Internet Group Multicast Protocol (IGMP) v2

• Multicast SSM (Single Source Multicast) deployed July 2003

Requires IGMP v3

• All Cisco® IP/TV®, VoD training, video and audio streaming uses multicast in the WAN

Server

Router

Single Data Stream

Receivers

Multiple Streams With IP Multicast


ASM and SSM

• Multicast SSM learns about sender IP address from the application; ASM learns from the Rendezvous Point router

• Multicast ASM requires complex multicast group and tree setup process; SSM is much simpler

• With ASM, multiple senders can send traffic within a multicast group, causing:

Excess network traffic

Traffic collisions

Possible security concerns

• SSM migration increased stability of multicast sessions


ASM and SSM

RP

Site 1

RP RP RP

Internet

DR

RP

IGMP v2 or v3

DR DR DR DR

PIMSupports

ASM and SSM SSM 2

SSMASM

SSM or ASMipmc source

ipmc sourceipmc source

ASM 4

ASM 2ASM 3

User recieving multicast

Multicast Source ServerSSM 2

ASM : Any Source Multicast SSM : Source Specific Multicast

ASM 1 SSM 1

ASM 1

ASM 2

ASM 3

ASM 4

SSM 1Host signals network to receive ipmctraffic for specific group address

Shared tree built from DR to RP toidentify the ipmc source servers IP addr

ipmc source servers DR router registerswith RP (this can happen first)

End Result : Shortest Path Tree built from ipmcsource to receive to deliver multicast traffic

Host signals network to receive ipmctraffic for specific group address

End Result : Shortest Path Tree built fromsource to receive to deliver ipmc traffic

IGMP v2 or v3

IGMP v2 or v3

IGMP v2 or v3

IGMP v2 or v3

RP Rendezvous point

DR Designated Router

Site 2 Site 3 Site 4 Site 5


Results: Multicast and SSM Is a Success

• Multicast is enabled and stable globally across 1035 routers

• SSM deployment is complete, with no unplanned network downtime or stability issues


Next Steps: New Multicast Applications

• Multicast Music on Hold support

Multicasting music on hold signal to multiple IP phones

• Info Cast support

Multicasting corporate announcements to IP phone displays

• Continue to monitor technology and standards for new multicast enhancements


This publication describes how Cisco has benefited from the deployment of its own products. Many factors may have contributed

to the results and benefits described; Cisco does not guarantee comparable results elsewhere.

CISCO PROVIDES THIS PUBLICATION AS IS WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING THE IMPLIED

WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Some jurisdictions do not allow disclaimer of express or implied warranties, therefore this disclaimer may not apply to you.

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© 2004 Cisco Systems, Inc. All rights reserved