Multicast in Wireless

7/29/2019 Multicast in Wireless

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2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 1

Multicast in Wireless

Cisco Systems Inc.


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Agenda

Multicast Overview

Why Multicast in Wireless?

Multicast Challenges in Wireless

Legacy Multicast Architecture

Reliable Multicast Feature

IPv6 in CUWN


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Unicast, Broadcast and Multicast


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What is IP Multicast?

Bandwidth Conserving Technology

Delivers source traffic to multiple receivers

Multicast Group Concept

Multicast packets are replicated in the network

Multicast delivery to hosts is controlled by:

Internet Group Management Protocol (IGMP) on IPv4 networks

Multicast Listener Discovery (MLD) on IPv6 networks

Inside a routing domain Protocol Independent Multicast(PIM) or MOSPF are used


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L3 Multicast Addressing

Controlled by Internet Assigned Numbers Authority (IANA)

Multicast Employs Class D Destination Address format

Multicast Range: 224.0.0.0- 239.255.255.255

224.0.0.0/24 Link Local, Reserved for Routing Protocols

224.0.1.0 through 238.255.255.255 Globally Scoped

239.0.0.0 through 239.255.255.255Administratively Scoped

233.0.0.0/8 Reserved for GLOP

Addressed to a Group of Intended Listeners

High order 4 bits set to 1110 followed by 28-bit Multicast group ID


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L2 Multicast Addressing

Network interface cards receive only packets destined for theirburned-in MAC address or the broadcast MAC address

LAN specifications made provisions for the transmission ofbroadcast and/or multicast packets

With Multicast Addressing, Multiple hosts receive same packet andstill be capable of differentiating among multicast groups


7/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 7

Mapping L3 to L2 (Class D to Ethernet)

Allows IP multicasting to take advantage of the hardware-levelmulticasting supported by network interface cards

Map low-order 23 bits of Class D address into low-order 23 bits in theEthernet MAC to correspond to the IP multicast group address

Available Ethernet MACs: 0100.5e00.0000 to 0100.5e7f.ffff



Sample L3 to L2 Mapping

Multicast group address 224.10.8.5 (E0-0A-08-05)mapped into an Ethernet (IEEE-802) multicast address

Mapping may place up to 32 diff. IP groups into same Ethernetaddr because upper 5 bits of IP multicast group ID are ignored



Transmission & Delivery of Multicast

Sender & Receiver on Same Subnet:

Source addresses IP packet to the multicast group

Network interface card maps Class D to IEEE-802 multicast address

Interested Receivers notify their IP layer that they want to receive

datagrams addressed to the group

Sender & Receiver on Different Subnets:

Routers required to implement multicast routing protocol that permitsconstruction of multicast delivery trees and supports multicast datapacket forwarding

Each router needs to implement a group membership protocol thatallows it to learn about the existence of group members on its directlyattached subnetworks



Internet Group Management Protocol

Allows hosts to inform local routers of their intention toreceive transmissions addressed to a specific group

Dynamically registers hosts in a multicast group on a particular LAN

Hosts identify group memberships by sending IGMP messages to their

local multicast routerRouters listen to IGMP messages and periodically send out queries todiscover which groups are active or inactive on a particular subnet

IGMP v2 Packet StructureType is Membership Query (0x11), Membership Report (IGMPv1: 0x12, IGMPv2: 0x16),

Leave Group (0x17) ; IGMPv3 adds type Membership Report (0x22)

+ Bits 0 - 7 8 - 15 16 - 23 24 - 31

0 Type Max Resp Time Checksum

32 Group Address



IGMP Snooping

Allows L2 Switches to Snoop L3 Multicast Data forIGMP Control Messages between hosts and routers

Allows switch to add or delete the hosts port number to theassociated multicast table entry

Since Multicast is like Broadcast, IGMP Snooping limits trafficto ports that need to receive data

Highly CPU intensive, recommended on High End Switcheswith SpecialASICs that perform IGMP checks in hardware



Simple IP Multicast Network

A network designed to deliver a multicast service (likevideo) using IGMP might use this basic architecture



Multicast Distribution Trees

Shortest Path Tree



Multicast Distribution Trees

Shared Tree Rendezvous Point (RP)



Multicast Forwarding

Unicast Forwarding only cares about destination IP

Multicast Forwarding checks source and destination

Reverse Path Forwarding

Forwards multicast traffic away from the source, rather than to thereceiver

Makes use of the existing unicast routing table to determine theupstream and downstream neighbors

RPF check helps to guarantee that distribution tree will be loop-free



Multicast Routing

Protocol Independent Multicast (PIM)

Uses unicast routing information to perform multicast forwardingfunction (RPF checks)

PIM Dense Mode

Push Model to flood Multicast Traffic

PIM Sparse Mode

Pull Model to deliver Multicast Traffic

Sparse Dense ModeMore efficient to choose sparse or dense on a per group basis ratherthan a per router interface basis



SAP and SDP

Session Directory Protocol (SDP)

Assists in advertising multimedia conference sessions and incommunicating setup information to participants who want to join thesession

Commonly used by a client to announce a conference session byperiodically multicasting an announcement packet to a well-knownmulticast address and port using SAP

Session Directory Announcement Protocol (SAP)

Used by SDP as its transport protocol

SAP and SDP display multicast session names andcorrelate the names with multicast traffic



References

Cisco IOS IP Multicast Configuration Guide, Rel. 12.4http://www.cisco.com/en/US/docs/ios/ipmulti/configuration/guide/12_4/imc_12_4_book.html
http://www.cisco.com/en/US/docs/ios/ipmulti/configuration/guide/12_4/imc_12_4_book.htmlhttp://www.cisco.com/en/US/docs/ios/ipmulti/configuration/guide/12_4/imc_12_4_book.htmlhttp://www.cisco.com/en/US/docs/ios/ipmulti/configuration/guide/12_4/imc_12_4_book.htmlhttp://www.cisco.com/en/US/docs/ios/ipmulti/configuration/guide/12_4/imc_12_4_book.html



MAIN DRIVERS

Why Multicast over Wireless?



Why Multicast over Wireless?

Increasing real time collaboration demands

Videoconferencing, Telepresence, Training, Surveillance etc.

Demand for Wired and Wireless System Integration

High throughput (better PHY and MAC) on 802.11n willimprove multicast delivery over wireless



Enterprise Video ApplicationsUnderstanding Diverse Application Models

Application

Model

Direction of

Flows/Type

Traffic

Requirements/Trends

Streaming Interactive VoD

Source >Clients

(Multicast)

Video

Surveillance

Live Digital

Media/Recorded

Playbacks

Many to

Few

Few to

Many

Storage > Storage

Storabe >Client

Source > Client

(Multicast)

IP Convergence

Opening up

usage andapplications

Higher quality

videorequirements

driving higher

bandwidth

Demand for

higher quality

video increaseseach stream

(SD: 18 Mbps

with Full MotionHD/DVD: 720

Mbps)

(up to 34 Mbpsper camera)

Desktop

Collaboration

TelePresence

Collaboration

Many to

Many

Many to

Many

Client Client

MCU Client

(Unicast)

Client Client

MCU Client

(Unicast)

High-def video

requires up to

412 Mbps perlocation

Collaboration

across

geographies

Growing peer-

to-peer modeldriving higher

on-demand

bandwidth

(Under 1 Mbps)

Video on Demand

Few to Many

Storage Client

(Unicast)

Tremendous increase

in applications driving

more streams

(SD: 14 Mbps; HD: 6

10 Mbps)



Sensitivity of Video Applications to QoS Requirements

Latency Jitter Throughput Packet Loss

Video

Teleconferencing

High High Low Medium

HD VideoTeleconferencing

High High High High

Video on

Demand

Low Low Medium Low

Live Streaming

Video

Medium Medium Medium High



Enterprise Video Trends

Source: IDC Video in the Enterprise: Snapshot, Sept 2009

34.3

40.8

41.3

44.9

54.4

61.5

0 10 20 30 40 50 60 70

Exec Communication/Live Streaming

Recorded playbacks

Sales Mtgs/Training

Video surveillance

Employee Training

Videoconferencing

Planned uses of Enterprise Video

% of customers

3.86.8

54.356.8

73.6

0 20 40 60 80

Other

On their mobile phones

On TVs in lobby, training rooms, etc.

Live on their PCs/Laptops

On demand on their PCs/Laptops

Where Employees watch Enterprise Video

% of customers



CHALLENGES

Multicast in Wireless


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Streaming Video Challenges TodayRadio Frequency Limitations

Cant deliver multicast video at scaleVideo overloads network and degrades other application performance

Video Streaming Without Reliable Multicast

AP APAP AP

POORPERFORMANCE

POORPERFORMANCE

WLC SWITCH

Unable to deliver business quality video


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Streaming Video ChallengesPoor Wired to Wireless Network Integration

No identification of respective priority

GOOD PERFORMANCEGOODPERFORMANCE

GOODPERFORMANCE

APAP APAP

WLC

Reliability at WLC improves quality but NOT overall scale

Inefficient use of overall network

POORPERFORMANCE

Inefficient use of

bandwidth on the

wired port

SWITCH


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Other Complexities

Variable Data Rates Packet Loss

Power Save Mode on Clients

Multicast Unreliability (due to Broadcast)


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Variable Data Rates

Variable Transmit Data Rate

User experience can vary widely over time

Since data rate of transmission over wireless varies over time

Depends on the distance of the client from the AP

Throughput of individual video flows and the capacity of the overallnetwork changes with time

Choosing the Right Transmit Data Rate for Multicast

All clients should have a chance to receive the packet (but at the same

time transmission is not so slow that it uses up all the airtime of thecell)


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Packet Loss

Unreliability due to underlying L2 Transport

Wireless loses more packets than wired

Collisions Two Wi-Fi devices attempting to transmit at the same time

Short-Term signal loss (fades) due to absorption, reflections etc.

Hunt for best data rate (some packets lost during the search process)

Combination of collisions, fades, and data rate selection canyield a packet error rate (PER) close to 5%

To compensate PER, Wi-Fi uses retransmissions whereby packets

that are not successfully received and acknowledged are resent

Retransmissions reduce the packet loss rate (PLR) to less than 0.1percent, but lead to jitter and eats into overall network throughput, bothof which can impact QoS


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Power Save Modes

If power-save mode is disabled, AP delivers multicasttraffic after each beacon (default interval = 100ms)

If power-save mode is enabled, AP buffers allmulticast frames and sends them after each DTIM

By default DTIM is every 1,2, or 3 beacon intervals on most APs

Due to buffering substantial delay of multicast frames may occur

DTIM and Beacon interval settings must be adjustedfor optimum performance of multicast


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Multicast Unreliability

Multicast traffic is Broadcast over the airOn the wired network, APs subscribe to a multi-cast group, but the multi-cast

traffic is then broadcast over air to all the associated clients

Broadcast not only consumes over-the-air bandwidth, but it also does not takeinto account the types of the connected devices

No reliable flow of data (no guaranteed delivery)

Multicast packets sent as UDP broadcast do not have the error correctionfeatures (ACK mechanism) that make up the core of the 802.11 standards

No Retransmissions implies PLR is equal to PER (~5%), which can be aserious problem for video (Loss of even a single packet can result in an error

that propagates for many video frames)


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Video Multicast: Broadcast Delivery

1

2

5.5

6

9

12

18

24

36

48

54

M0

M1

...

M14

M15

802.11Data Rates

B/G

N

VideoServer

AP 1140

Multicast packets (UDP) are sent asbroadcast packets over the air per802.11 standard

Broadcast packets do not use errorcorrection: fire and forget

Broadcast packets are sent at thehighest mandatory data rate:

1 MB for B/G (400K actual)6 MB for A (2.7 MB actual)

Technical Challenges

Choppy, Unreliable Video

Video Stream does not utilize802.11 N High Throughputdata rates

Heavy utilization of channeldue to high rate of very slowpackets

Video delivery is not reliablecausing poor Quality ofExperience

Video Impact

Default 802.11B/Gmandatory data rates


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Broadcasting Multicast VideoAffect on AP Channel

1 MB Data RatePackets

400 KBMax

1 MBVideo

Stream

802.11G/N AP Coverage BoundaryCell Edge

Channel utilizationmaxed out

Hub environmentaffects ALL clientsin cell

Wireless becomesunusable

Multicast video stream works fine on wired

Video stream choppy on wireless

Entire WiFi cell consumed with video


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LEGACY MULTICASTARCHITECTURE

Multicast on the Cisco Unified Wireless Network


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Multicast Modes on WLC

Broadcast Forwarding

Multicast Forwarding

Multicast: Unicast

Multicast: Multicast


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Multicast Behavior in WLC Versions

Before WLC Release 4.0.206.0Unicast or Multicast mode, also enabled Broadcast

After WLC Release 4.0.206.0

Broadcast and Multicast traffic must be enabled separately

config network broadcast enable

If multicast mode is Unicast and broadcast is turned on,broadcast traffic is replicated and unicast to each AP

If multicast mode is Multicast with a multicast address, each

broadcast packet is sent via the multicast group to the APs

After WLC Release 4.2

IGMP Snooping Introduced


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Enabling IGMP Snooping

Enabled from Controllers > Multicast menu

Plays an important role to facilitate client roaming

IGMPv1 and v2 are only supported currently


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Multicast: Unicast

Doing Multicast conversion at the Controller puts a burden on theController. In addition it strains the network resources (higherstreams)

One multicast packet inLWAPP

EncapsulatedPackets

Multiple Copies ofthe same Multicast PacketEncapsulated with LWAPP

Unicast packets out to each AP

Processor Intensive


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Multicast: Multicast

One multicast packet in LWAPPMulticast Group

One LWAPP Encapsulated multicast

packet out

Network replicatespacket as needed

Improved multicast performance over wireless networks

Multicast packet replication occurs only at points in the network where it isrequired, saving wired network bandwidth

Pre-requisite: Multicast Enabled network between the Controller and APs

More efficient than Unicast.

Less Processor Intensive.


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Multicast Source on Wired LANMulticast: Multicast

AP downloads LWAPP multicast group addr. during join process

AP issues IGMP JOIN to the controller LWAPP multicast group

Controller becomes multicast source and AP as multicast receiver

Client sends IGMP report to JOIN a multicast stream

Controller intercepts (IGMP snoop) and parses the report

Builds MGID database of multicast groups required by client

Sends proxy JOIN report to multicast router

Forwards multicast to ALL APs using Multicast LWAPP tunnel

AP forwards the multicast stream to client

Based on MGID database subscription entries

Duplicates a copy to each WLAN with a subscription

Sends multicast packets as broadcast on default WLAN QoS priority


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Multicast Source on Wireless LAN

AP to WLC: Similar to normal wireless traffic

Multicast packet from client is LWAPP-encapsulated andunicast from AP to WLC

Controller makes two copies of the multicast packet:

One copy is sent out the VLAN associated with the WLANSSID on which it arrived. This enables receivers on the wiredLAN to receive the multicast stream and the router to learnabout the new multicast group.

The second copy of the packet is LWAPP-encapsulated and issent to the LWAPP multicast group so that wireless clients can

receive the multicast stream.


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Multicast Source on Wired LANNo IGMP Snooping

LWAPP

Mcast Traffic

IG

MP

BroadcastBroadcast

Clients IGMP Join request is bridged tothe router

Controller forwards multicast packets tothe LWAPP multicast group address

using its management interface at thelowest QoS level

All APs in multicast group receive thepacket and broadcast it to all the

BSSIDs mapped to the interface onwhich clients receive multicast


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The IGMP Join No IGMP Snooping

Mcast Traffic

Client sends an IGMP join

Controllerbridges the IGMP jointhrough the upstream switch to thePIM enabled router

Cam Table Entry Added

01:00:5E:XX:XX:XXROUTER#show ip igmp groups

IGMP Connected Group Membership

Group Address Interface Uptime Expires Last Reporter

233.0.0.1 Vlan119 3w1d 00:01:52 10.1.1.130

IP 10.1.1.130

(*,G)

Controller IP 10.1.1.2

IGMP is Bridged


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The IGMP Leave No IGMP Snooping

Mcast Traffic

Client sends an IGMP leave

Controller bridges the IGMP leavethrough the upstream switch to thePIM enabled router

Cam Table Entry Deleted

01:00:5E:XX:XX:XX

IP 10.1.1.130

(*,G)

IGMP is BridgedController IP 10.1.1.2


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Multicast Delivery With IGMP SnoopingIntroduced 4.2

Controller acts as IGMP proxy and facilitatesroaming

Controller periodically sends IGMP queries toclients to update its MGID database

Controller forwards Multicast (either unicast or

multicast) to all APs

Only those APs that have active clientssubscribed (based on MGID table) to themulticast group broadcast multicast traffic onthat particular WLAN, otherwise it is dropped

LWA

PP

Mcast Traffic

IGMP

Broadcast

SSID MGID

Blizzard NONE

Tsunami NONE

SSID MGID

Blizzard 233.0.1.1

Tsunami NONE


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The IGMP Join Snooping Enabled

Mcast Traffic

Client sends an IGMP join Controller intercepts the join and creates a

table entry for the client multicast group

Controller then proxies IGMP join throughupstream switch to the PIM enabled router

Cam Table Entry Added

01:00:5E:XX:XX:XX

ROUTER#show ip igmp groups

IGMP Connected Group Membership

Group Address Interface Uptime Expires Last Reporter

233.0.0.1 Vlan119 3w1d 00:01:52 10.1.1.2

IP 10.1.1.130

(*,G)


This is the controller!!


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The IGMP Leave Snooping Enabled

IGMP

IGMP

Mcast TrafficClient sends an IGMP leave

Controller intercepts the leave and removes thetable entry for the client multicast group

NO leave is forwarded to network, it will timeout based on the configuration of the controller

Cam Table Entry Remains

01:00:5E:XX:XX:XX

IP 10.1.1.130

(*,G)


X


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Multicast Group Identifier (MGID)

Assists with packet classification, identification and roaming

L2 MGIDs are assigned when L2 multicast or broadcast is enabled

L3 MGIDs are assigned when the client requests membership in aparticular IP multicast group through the use of IGMP.


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CLI to Check MGID


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All Multicast Groups

All multicast groups and their corresponding MGIDs:(Controller) >show network multicast mgid summary

Layer2 MGID Mapping:

InterfaceName vlanId MGID

corp1 260 11

guest 240 13

management 320 0

voice 251 12

Layer3 MGID Mapping:

Number of Layer3 MGIDs........................... 6

Group address Vlan MGID

224.0.0.251 260 550

224.0.0.252 260 555

224.0.1.60 260 554

224.1.0.38 260 628

239.255.255.250 260 564

239.255.255.253 260 596


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Clients Joined to Multicast Group

All clients joined to multicast group in a specific MGID:(Controller)>show network multicast mgid detail 564

Mgid........................................ 564

Multicast Group Address..................... 239.255.255.250

Vlan........................................ 260

No of clients............................... 2

Client List.................................

Client MAC AP Name Expire Time(mm:ss) Multicast-Status Qos User Priority

00:21:5c:88:38:e7 sjc14-41b-ap5 0:43 Normal Multicast 0

00:21:5c:8c:b8:81 sjc14-31b-ap3 0:59 Normal Multicast 0


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Client Roaming with IGMP

The first controller transmits all the multicast groupinformation for the listening client to the secondcontroller.

The second controller can immediately create the

multicast group information for the client.

The second controller sends the IGMP reports to thenetwork for all multicast groups to which the client waslistening. This process aids in the seamless transfer of

multicast data to the client.


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Layer 2 Roaming Client

IGMP Join on Controller 1

Traffic flows to client

Client ROAMS to a new controller

IGMP

Mcast Traffic

X

IG

MP

Router#show mac-address-table multicast vlan 119

vlan mac address type learn qos ports-----+---------------+--------+-----+---+--------------------------------119 0100.5e00.0101 static Yes - Gi1/23,Router

Beginning with 4.0.206.0

General IGMP Query sent from the WLC tothe client, allowing traffic to flow

Gi1/23

(*,G)

Gi3/28


vlan mac address type learn qos ports-----+---------------+--------+-----+---+--------------------------------119 0100.5e00.0101 static Yes - Gi1/23, Gi3/28,

Router


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Layer 2 Roaming Client

IGMP Join on Controller 1

Traffic flows to client

Client ROAMS to a new controller

Mcast Traffic

X

IG

MP


vlan mac address type learn qos ports-----+---------------+--------+-----+---+--------------------------------119 0100.5e00.0101 static Yes - Gi1/23,Router

Beginning with 4.2

Multicast Group Information is sent withmobility exchange

Gi1/23

(*,G)

Gi3/28


vlan mac address type learn qos ports-----+---------------+--------+-----+---+--------------------------------119 0100.5e00.0101 static Yes - Gi1/23, Gi3/28,

Router


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LWAPP Layer 3 Roaming Client

IGMP Join/Leave

Both the initial join and leave (if agraceful leave happens) will be

processed the same way as any otherjoin or leave. Once a client has roamed,neither the infrastructure nor the clientare required to send a new join toverify traffic follows

Multicast SourceClient that is the Source of themulticast group on the upstream routerwill drop the packet as the sourceaddress was received on the wronginterface

Mcast Traffic

??

X


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References

Multicast with WLCs and LAPs Configuration Examplehttp://www.cisco.com/en/US/tech/tk722/tk809/technologies_configuration_example09186a00807cc10d.shtml
http://www.cisco.com/en/US/tech/tk722/tk809/technologies_configuration_example09186a00807cc10d.shtmlhttp://www.cisco.com/en/US/tech/tk722/tk809/technologies_configuration_example09186a00807cc10d.shtmlhttp://www.cisco.com/en/US/tech/tk722/tk809/technologies_configuration_example09186a00807cc10d.shtmlhttp://www.cisco.com/en/US/tech/tk722/tk809/technologies_configuration_example09186a00807cc10d.shtmlhttp://www.cisco.com/en/US/tech/tk722/tk809/technologies_configuration_example09186a00807cc10d.shtml


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NEW SOLUTION

Reliable Multicast - Cisco VideoStream


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Video Multicast Delivery Solution

1

2

5.5

6

9

12

18

24

36

48

54

M0M1

...

M14

M15

802.11Data Rates

B/G

N

VideoServer

AP 1140

IGMP state monitored for each client. Onlysend video to clients requesting

Multicast packets replicated at AP and sent toindividual clients at their data rate

Resource Reservation Control (RRC) used toprevent channel oversubscription. Works inconjunction with Voice CAC

Stream Prioritization ensures importantvideos take precedence over others

SAP/SNMP error message created whenChannel Subscription violated

Technical Solution

Smooth, Reliable Videodelivered to multiple clients

Quality of Video protected invarying channel loadconditions

Prevents video flooding

Prioritizes Business Videoover other video

Video Impact

Default 802.11B/Gmandatory data rates

Intelligencein the AP

QoS Markedon CAPWAPFrom WLC


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VideoStream Technology

Cisco VideoStream Technology is a new system-wide set offeatures that enable reliable and consistent delivery of quality

video over the wireless network

Multicast Direct orReliable Multicast

AP

MULTICAST STREAM

StreamPrioritization

WLC

COMPANY ALL HANDS

Training Program

AP

Live Sporting Event

Resource ReservationControl

AP

VIDEONOTAVAILABLE


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Feature Overview

Stream Admission & Prioritization Identify specific Video Streams for preferentialQoS treatment

Resource Reservation Control(RRC)

Quality of Video Enforcement by denying clientwhen channel busy

Video Bandwidth protection to prevent video fromconsuming wifi channel

Multicast Direct Sends multicast video stream as unicast directlyto client

Video QoS promotion

Enables use of 11n data rates and standardspacket error correction

Monitoring Client alert for insufficient bandwidth

SNMP trap for QoS/bandwidth problem

Roaming Support (existing) Roaming with pre-built multicast flows Proxy IGMP join (cross controller roam)

IGMP snooping (existing) Prevents video flooding


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Stream Admission & Prioritization

Identify specific Video Streams for preferential QoS treatment

Configure media streams with different priorities based onimportance within the organization

Can be enabled at the radio (2.4 or 5 GHz) and at the WLAN level

Allows specific video streams for preferential QoS treatment (Lowerpriority than voice and higher priority than best effort)

Clients can either be forced out of high priority level or dropped

8 Priority levels defined 8 being the highest and 1 being the lowest

E.g. Companywide address from CEO takes precedence over a replay of sporting event


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Resource Reservation Control (RRC)

RRC provides enhanced capabilities to manageadmission and policy controls

Admission & policy decisions made based on the RF measurements,statistics measurement of the traffic, and system configurations

Provides bandwidth protection for video clients by denying requeststhat would cause oversubscription (SAP messages to clients on drop)

Channel utilization used as a metric to determine capacity and performadmission control


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Multicast Direct

Reliable MulticastMonitors IGMP JOIN results from clients for the configured streams

Signals the AP to put the video packet in the RIGHT TX queue

Video & Voice measurements are considered from the AP

RRC engine approved stream will be admitted with the JOIN response

Direct Memory Access (DMA)

On-the-fly copying of video streams at the AP (replication)

Packet header modification to UnicastSends multicast video stream as unicast directly to the client

Video QoS promotion

Enables use of 11n data rates and packet error correction

Multicast Direct Architecture


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Multicast Direct ArchitectureController Admission Control with realtime radio statistics

MGIDMulticastDirectApplication

VideoResource

and ControlMulticast

Direct

Application

MeasurementEngine

IGMPSnooping

WLCAP

ForwardingModule

Policy &Configuration

Router


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Monitoring

Realtime SAP/SDP denial message

Immediate feedback to client

SNMP Traps sent to the controller


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Auto QoS

Needs to be implemented on wired side to preventEthernet overruns for 802.11n AP

Reduces probability of drop for high priority Video

frames.

Much better End User Experience for multi-media

Media Ready WLAN with VideoStream


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ADMISSION

CONTROL

VIDEO

NOTAVAILABLE

Media Ready WLAN with VideoStreamWireless Investment Optimized for Video

Solved challenges associated with RF and wired / wireless integrationBrings wired video quality to wireless

Improves quality and scale of streaming content :

CRITICALITYLEVEL:

HIGH

GREATPERFORMANCEGREATPERFORMANCE GREATPERFORMANCE

APAP APAP

WLC SWITCH

Stream prioritization protects important content precedence

Reliable

Multicast

Prioritization

RRC


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Benefits of Reliable Multicast

Transmissions adapt to individual client data rate

Reliable retransmission minimizes loss

Ensures QoS priority and quality

Configurable and manageable bandwidth usage Co-existence with voice

Fast and efficient video packet copying

Pushing it out to the very edge of the network reduces the amount of

traffic that flows over the wired network

Because unicast requires ACK from each client, Multicast Directmakes intelligent decisions about where video shouldnt go i.e. to

APs that get no requests - to conserve bandwidth.


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Reliable Multicast Support

Hardware Support

Controllers: Cisco 5500 series, Cisco 4400 series, Cisco Catalyst 6500Series/7600 Series, Wireless Services Module, Cisco 3750G IntegratedWireless LAN Controller

Access Points: Cisco Aironet 1140 Series, Cisco Aironet 1250 Series,Cisco Aironet 1240AG Series*, Cisco Aironet 1130AG Series*

Software Support

J Release (7.0.XX.XX)

To select customers on 6.0.188.0


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CONFIGURATIONS

Reliable Multicast


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Multicast Direct - Global

Wireless > Media Streams > General


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Multicast Direct Per WLAN

WLANs > Edit > QoS


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MGID Detail with Multicast Direct

Two clients, one with normal Multicast and the otherwith Multicast direct configured on WLAN


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Stream Prioritization on WLC

Wireless > Media Streams > Streams


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Media Parameters

Wireless > 802.11 (a)(b/g) > Media


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PERFORMANCE METRICS

Reliable Multicast


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Meircom Lab Testing Summary

VideoStream significantly improves the WLAN MDIMedia Delivery Index (MDI): A metric that combines delayfactor and media loss rate to determine video streaming quality

Ref: Miercom Lab Testing Summary Report

http://wwwin.cisco.com/ewtg/wnbu/campaigns/docs/Cisco_5508WC_Miercom_Report.pdf

End-to-End Quality Video Delivery
http://wwwin.cisco.com/ewtg/wnbu/campaigns/docs/Cisco_5508WC_Miercom_Report.pdfhttp://wwwin.cisco.com/ewtg/wnbu/campaigns/docs/Cisco_5508WC_Miercom_Report.pdfhttp://wwwin.cisco.com/ewtg/wnbu/campaigns/docs/Cisco_5508WC_Miercom_Report.pdfhttp://wwwin.cisco.com/ewtg/wnbu/campaigns/docs/Cisco_5508WC_Miercom_Report.pdf


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End to End Quality Video DeliveryVideoStream Delivers Better MDI and Meets SLA

Media Delivery Index (MDI):

Metric for assessing networks ability to deliver quality video to end user

Indication of video transport performance based on network level measured viacombination of Delay Factor (DF) & Media Loss Rate

Delay Factor (DF): Measures Jitter orEnd-to-end Latency with Respect to Time

Before

After

At the Higher End of RecommendedThreshold of 50ms

Below 2ms

Media Loss Rate (MLR): PacketsDropped or Out-of-Order Packets

Before

After

Above 10 Pkts/Min Recommended Threshold. At31% Loss for SD and 82% Loss for HD.

Zero Loss

78

2

76

0

20

40

60

80

8854

89750

0

20000

40000

60000

80000

100000

VideoStream

Off

VideoStream

On

DF (msec)

MLR (Pkts/min)

5x SD

Streams5x HD

Streams

5x SD

Streams

5x HD

Streams

0 0

0

S


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Video StreamNo. of Video

clientsQuality

500kbps 20 Excellent

1500kbps 20 Very Good

3000kbps 13 Good

Reliable Multicast Scalability


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IPV6 SUPPORT ON CUWN

IPv6 and Multicast


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IPv6 Addressing

Multicast is part of the base specification of IPv6IPv6 does not implement broadcast, but IPv6 multicast sharescommon features & protocols with IPv4 multicast

Incorporates 128 bit source and destination addresses

Multicast addresses in IPv6 have the prefix ff00::/8

bit field size: 8 4 4 112

content: 11111111 flags scope group identification


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IPv6 Multicast Addressing

Field Name Size (bits) Description

(Indicator) 8 The first eight bits are always 1111 1111 to indicate a multicast address.

Flags 4

Flags:Four bits are reserved for flags that can be used to indicate the nature of certain multicast addresses. Atthe present time the first three of these are unused and set to zero. The fourth is the T (Transient) flag. If leftas zero, this marks the multicast address as a permanently-assigned, well-known multicast address, as we

will see below. If set to one, this means this is a transientmulticast address, meaning that it is not permanentlyassigned.

Scope ID 4

Group ID 112 Group ID:Defines a particular group within each scope level.


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IPv6 Support on CUWN

IPv6 Configuration on the WLCMulticast Mode required on WLC for IPv6 (Unicast or Multicast)

CSCsg78164: IPV6 Passthrough does not work unless Mulitcast mode is enabled

Enable IPv6 check box on the WLAN SSID

With WLC 4.2 Release:

IPv6 Bridging (Client Pass-Through), but no L2 Security on IPv6 WLAN

IPv6 over IPv4 tunneling on open WLAN and Webauth WLAN.

With WLC 6.0 Release:

IPv6 pass-thru with Layer-2 security is supported.

Same WLAN can support both IPv4 and IPv6 clients

IPv6 pass-thru and IPv4 Webauth is supported on same WLAN.


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IPv6 Capabilities: IPv6 over IPv4 Tunneling

Support for tunneling IPv6 over IPv4 in the Unified Solution

IPv6 Unicast and Multicast tunneling supported

Infrastructure must have Dual Stacks: IPv4 and IPv6 No IPv6 support on WCS, MSE and Location Appliance

AP| 802.11 | IPv6 |

| IPv4 | CAPWAP | 802.11 | IPv6 | | Ethernet II | IPv6 |

ControllerClient IPv6 traffic tunneled

over IPv4 and bridged to

Ethernet


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IPv6 and IPv4 on same WLAN

IPv6 over IPv4 tunneling on open WLAN and Web-AuthWLAN supported today (4.2)

IP 6 Li i i i CUWN


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IPv6 Limitations in CUWN

L3 mobility across controllers doesnt work

VoWLAN or any other differentiated services dont work

Qos Prioritization doesnt work (WLCs dont understand IPv6)

ACLs dont work

Guest Access (Web Auth) doesnt work

Web Auth needs the WLC to understand IPv6 to intercept the redirectHTTP over IPv6

WLCs cannot be managed over IPv6

IP 6 R d


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IPv6 Roadmap

Highly Desired (On Roadmap - Need to check)Support for IPv6 in IPv4 Tunnels (Full Mobility support, All L2 Authtypes)

Support for QoS, ACLs, VoIP

Support for Web-Auth

Support for Guest Mobility Anchor Tunneling

IPv6 Client Address Assignment

Native IPv6 Support: Native IPv6 on AP, Controller, MSE, WCS etc.


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Documents

Multicast in Wireless