multicast in wireless
TRANSCRIPT
-
7/29/2019 Multicast in Wireless
1/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 1
Multicast in Wireless
Cisco Systems Inc.
-
7/29/2019 Multicast in Wireless
2/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 2
Agenda
Multicast Overview
Why Multicast in Wireless?
Multicast Challenges in Wireless
Legacy Multicast Architecture
Reliable Multicast Feature
IPv6 in CUWN
-
7/29/2019 Multicast in Wireless
3/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 3
Unicast, Broadcast and Multicast
-
7/29/2019 Multicast in Wireless
4/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 4
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
-
7/29/2019 Multicast in Wireless
5/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 5
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
-
7/29/2019 Multicast in Wireless
6/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 6
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
-
7/29/2019 Multicast in Wireless
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
-
7/29/2019 Multicast in Wireless
8/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 8
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
-
7/29/2019 Multicast in Wireless
9/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 9
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
-
7/29/2019 Multicast in Wireless
10/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 10
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
-
7/29/2019 Multicast in Wireless
11/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 11
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
-
7/29/2019 Multicast in Wireless
12/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 12
Simple IP Multicast Network
A network designed to deliver a multicast service (likevideo) using IGMP might use this basic architecture
-
7/29/2019 Multicast in Wireless
13/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 13
Multicast Distribution Trees
Shortest Path Tree
-
7/29/2019 Multicast in Wireless
14/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 14
Multicast Distribution Trees
Shared Tree Rendezvous Point (RP)
-
7/29/2019 Multicast in Wireless
15/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 15
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
-
7/29/2019 Multicast in Wireless
16/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 16
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
-
7/29/2019 Multicast in Wireless
17/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 17
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
-
7/29/2019 Multicast in Wireless
18/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 18
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 -
7/29/2019 Multicast in Wireless
19/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 19
MAIN DRIVERS
Why Multicast over Wireless?
-
7/29/2019 Multicast in Wireless
20/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 20
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
-
7/29/2019 Multicast in Wireless
21/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 21
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)
-
7/29/2019 Multicast in Wireless
22/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 22
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
-
7/29/2019 Multicast in Wireless
23/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 23
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
-
7/29/2019 Multicast in Wireless
24/88 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 24
CHALLENGES
Multicast in Wireless
-
7/29/2019 Multicast in Wireless
25/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 25
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
-
7/29/2019 Multicast in Wireless
26/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 26
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
-
7/29/2019 Multicast in Wireless
27/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 27
Other Complexities
Variable Data Rates Packet Loss
Power Save Mode on Clients
Multicast Unreliability (due to Broadcast)
-
7/29/2019 Multicast in Wireless
28/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 28
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)
-
7/29/2019 Multicast in Wireless
29/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 29
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
-
7/29/2019 Multicast in Wireless
30/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 30
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
-
7/29/2019 Multicast in Wireless
31/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 31
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)
-
7/29/2019 Multicast in Wireless
32/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 32
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
-
7/29/2019 Multicast in Wireless
33/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 33
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
-
7/29/2019 Multicast in Wireless
34/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 34
LEGACY MULTICASTARCHITECTURE
Multicast on the Cisco Unified Wireless Network
-
7/29/2019 Multicast in Wireless
35/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 35
Multicast Modes on WLC
Broadcast Forwarding
Multicast Forwarding
Multicast: Unicast
Multicast: Multicast
-
7/29/2019 Multicast in Wireless
36/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 36
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
-
7/29/2019 Multicast in Wireless
37/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 37
Enabling IGMP Snooping
Enabled from Controllers > Multicast menu
Plays an important role to facilitate client roaming
IGMPv1 and v2 are only supported currently
-
7/29/2019 Multicast in Wireless
38/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 38
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
-
7/29/2019 Multicast in Wireless
39/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 39
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.
-
7/29/2019 Multicast in Wireless
40/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 40
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
-
7/29/2019 Multicast in Wireless
41/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 41
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.
-
7/29/2019 Multicast in Wireless
42/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 42
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
-
7/29/2019 Multicast in Wireless
43/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 43
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
-
7/29/2019 Multicast in Wireless
44/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 44
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
-
7/29/2019 Multicast in Wireless
45/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 45
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
-
7/29/2019 Multicast in Wireless
46/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 46
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)
Controller IP 10.1.1.2
This is the controller!!
-
7/29/2019 Multicast in Wireless
47/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 47
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)
Controller IP 10.1.1.2
X
-
7/29/2019 Multicast in Wireless
48/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 48
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.
-
7/29/2019 Multicast in Wireless
49/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 49
CLI to Check MGID
-
7/29/2019 Multicast in Wireless
50/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 50
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
-
7/29/2019 Multicast in Wireless
51/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 51
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
-
7/29/2019 Multicast in Wireless
52/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 52
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.
-
7/29/2019 Multicast in Wireless
53/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 53
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
Router#show mac-address-table multicast vlan 119
vlan mac address type learn qos ports-----+---------------+--------+-----+---+--------------------------------119 0100.5e00.0101 static Yes - Gi1/23, Gi3/28,
Router
-
7/29/2019 Multicast in Wireless
54/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 54
Layer 2 Roaming Client
IGMP Join on Controller 1
Traffic flows to client
Client ROAMS to a new controller
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 4.2
Multicast Group Information is sent withmobility exchange
Gi1/23
(*,G)
Gi3/28
Router#show mac-address-table multicast vlan 119
vlan mac address type learn qos ports-----+---------------+--------+-----+---+--------------------------------119 0100.5e00.0101 static Yes - Gi1/23, Gi3/28,
Router
-
7/29/2019 Multicast in Wireless
55/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 55
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
-
7/29/2019 Multicast in Wireless
56/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 56
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 -
7/29/2019 Multicast in Wireless
57/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 57
NEW SOLUTION
Reliable Multicast - Cisco VideoStream
-
7/29/2019 Multicast in Wireless
58/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 58
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
-
7/29/2019 Multicast in Wireless
59/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 59
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
-
7/29/2019 Multicast in Wireless
60/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 60
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
-
7/29/2019 Multicast in Wireless
61/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 61
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
-
7/29/2019 Multicast in Wireless
62/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 62
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
-
7/29/2019 Multicast in Wireless
63/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 63
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
-
7/29/2019 Multicast in Wireless
64/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 64
Multicast Direct ArchitectureController Admission Control with realtime radio statistics
MGIDMulticastDirectApplication
VideoResource
and ControlMulticast
Direct
Application
MeasurementEngine
IGMPSnooping
WLCAP
ForwardingModule
Policy &Configuration
Router
-
7/29/2019 Multicast in Wireless
65/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 65
Monitoring
Realtime SAP/SDP denial message
Immediate feedback to client
SNMP Traps sent to the controller
-
7/29/2019 Multicast in Wireless
66/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 66
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
-
7/29/2019 Multicast in Wireless
67/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 67
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
-
7/29/2019 Multicast in Wireless
68/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 68
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.
-
7/29/2019 Multicast in Wireless
69/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 69
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
-
7/29/2019 Multicast in Wireless
70/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 70
CONFIGURATIONS
Reliable Multicast
-
7/29/2019 Multicast in Wireless
71/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 71
Multicast Direct - Global
Wireless > Media Streams > General
-
7/29/2019 Multicast in Wireless
72/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 72
Multicast Direct Per WLAN
WLANs > Edit > QoS
-
7/29/2019 Multicast in Wireless
73/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 73
MGID Detail with Multicast Direct
Two clients, one with normal Multicast and the otherwith Multicast direct configured on WLAN
-
7/29/2019 Multicast in Wireless
74/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 74
Stream Prioritization on WLC
Wireless > Media Streams > Streams
-
7/29/2019 Multicast in Wireless
75/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 75
Media Parameters
Wireless > 802.11 (a)(b/g) > Media
-
7/29/2019 Multicast in Wireless
76/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 76
PERFORMANCE METRICS
Reliable Multicast
-
7/29/2019 Multicast in Wireless
77/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 77
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 -
7/29/2019 Multicast in Wireless
78/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 78
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
-
7/29/2019 Multicast in Wireless
79/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 79
Video StreamNo. of Video
clientsQuality
500kbps 20 Excellent
1500kbps 20 Very Good
3000kbps 13 Good
Reliable Multicast Scalability
-
7/29/2019 Multicast in Wireless
80/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 80
IPV6 SUPPORT ON CUWN
IPv6 and Multicast
-
7/29/2019 Multicast in Wireless
81/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 81
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
-
7/29/2019 Multicast in Wireless
82/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 82
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.
-
7/29/2019 Multicast in Wireless
83/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 83
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.
-
7/29/2019 Multicast in Wireless
84/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 84
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
-
7/29/2019 Multicast in Wireless
85/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 85
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
-
7/29/2019 Multicast in Wireless
86/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 86
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
-
7/29/2019 Multicast in Wireless
87/88
2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 87
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.
-
7/29/2019 Multicast in Wireless
88/88