ip multicast and iptv customer day ip multicast summit 06 ... · mc pkt l20 l30 “swap”...
TRANSCRIPT
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 1
IP Multicast and IPTV
Customer DayIP Multicast Summit
06/13/2008
Toerless Eckert
Technical Leader
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 2
Content
Cut down version of Multicast IPTV Networkers 2008 (Orlando) Breakout Session (in two weeks)
Session BRKVVT-2102
Will provide full presentation
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 3
Cisco ‘IPTV’ Solutions
Wide range of IPTV related solutions in various stages of customer facing documentation
Basic IPTV for Wireline and Cablehttp://www.cisco.com/en/US/products/ps6902/prod_release_notes_list.html
VAMS WhiteTip(CIC, Tivoli, Netcool, ANA + CMM)http://www.cisco.com/en/US/products/ps9518/index.html
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 4
AgendaIntroduction
Architectural overview
IP multicast primer (SSM)
Transit Transport Design options
Resiliency
Broadband Edge
Admission control
Channel changing
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 5
IntroductionIPTV and
IP multicast
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 6
…however transport network transits packets ..“Native IP multicast”, MPLS, L2, optical
IP multicast sources:Encoder, Transrater, Groomer, Ad-Splicer, …
IP multicast receivers:Transcoder, Groomer, Ad-Splicer, eQAM, STB
IP == IPv6 (Japan) or IPv4 (RotW rest of the world)No address exhaustion issue (SSM)No/slow move to IPv6 for IPTV in RotW
Broadcast IPTV = IP multicast
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 7
Deployment strategyOverview, Recommendation
NetworkAdd IP multicast service to your network (for any application)
Choose transport methods based on SLA and operational requirements/preferences
Native IP multicast, MPLS, L2, mix
Solution should minimize involvement in provisioning of individual applications/services
IPTV servicesStart with traditional broadcast TV
Investigate extending IPTV and add other (IP multicast) services
More RoI on network layer investment
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 8
Additional service/application opportunitiesAcross common SSM IP multicast service
No need to change the IP multicast functionality in the networkMay want improvements on optional elements (RSVP, …)
Extending IPTV broadcast serviceDynamic redundancy (regional to national) Variety of reach of transmission (src->rcvr)
Groomer/Transraters, Ad-SplicersIPTV broadcast vs. Switched Digital Video, oversubscriptionWholesale, dynamic, international channels
Other servicesCommercial (MVPN)Content pre-provisioning to VoD server, STBMulticast in Internet Service (eg: To PC)Voice conferencing, gaming, surveillance, …
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 9
Architectural Overview
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 10
50,000 feet architectureIPTV and multicast
“Network Plane”
IPTV “Services Plane”
IP multicastsource IP multicast
receiver
IP multicastService gateway
Receive/process/sendEg: Ad-Splicer, Dserver, Transrater,…
The network
Sign
alin
g
Sign
alin
g
Sign
alin
g
Service Interface
Multicast trafficMulticast traffic
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 11
50,000 feet architectureGoals
Separate “network” and “services” planeNetwork = shared infrastructure for all services
Routers, switches, optical gear, NMS, …IPTV = encoders, groomers, splicers, VoD server, STB, …
Often operated by different entity/group than networkIP multicast
Allow to attach service plane devices (sourcing, receiving) anywhere – global, national, regional, local. Start/stop sending traffic dynamically, best utilize bandwidth only when needed.
One network technology usable for all services (IPTV, MVPN, …)Different transport options for different services possible
Enable network operator not to provision/worry about individual programming.
Service InterfaceHow network & service operator infrastructure interacts with each otherSLA of IP multicast traffic sent/received, Signaling used
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 12
IP multicast primer (SSM)… as required for IPTV…
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 13
Protocols and Services…and IP multicast
multicast / multipoint protocolsBetween routers, switches, ..
“Only of interest to network operator”
PIM-SM, MSDP, (M)BGP, AutoRP, BSR, mLDP, RSVP-TE, …), IGPs(OSPF, ISIS), …
multicast servicesHow end-devices can use IP multicast
“Of interest to network and service operator”
ASM, SSM (and protocols “IGMP/MLD”)
Service operator just need to add SLA requirements!
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 14
IP multicast services
ASM: “Any Source Multicast” (1990, rfc1112)
The “traditional IP multicast service” (collaborative)Sources send packets to multicast groupsReceivers join to (G) groups, receive from any source
SSM “Source Specific Multicast” (~2000, rfc4607/4604)The multicast variant for IPTV (or other “content distribution”)Unchanged: Sources send packets to multicast groupsReceivers subscribe (S,G) channels,receive only traffic from S sent to G Primarily introduced (by IETF) for IPTV type services
Because of limitations of standard (protocol) model for ASM
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 15
IP multicast servicesIssues with ASM – resolved with SSM
ASMDoS attacks by unwanted sources
Address allocation (IPv4 only, not IPv6)
Standard protocol suiteComplexity of protocol operations required
PIM-SM (RPT+SPT+Switchover), RP redundancy, announce, location
MSDP (RPF), BGP congruency,
Interactions with MPLS cores, bandwdith reservation, protection
Scalability, Speed of protocol operations (convergence)RPT + SPT operations needed
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 16
End-to-end protocol viewHistoric development
STBHomeGatewayDSLAMPE-AGG
Aggregation Home NetAccessNationalcontent
Regional/ localcontent
Old designs: Use non-IP satellite distribution, inject regional / locally“National IP network can not transport video (cost, function)”
Current designs: use regional/local injection only for regional/local contentThe national core IP network can transport video optimallyMay also want to feed local/region back across core (national redist)
ReceiverDisk in every Agg. region
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 17
End-to-end protocol viewexample: L3 aggregation
PIM-SSM (S,G) joins IGMPv3 (S,G) membership
STBHomeGateway
BB typespecificPE-AGG
Core Distribution/ regional
Aggregation Home NetAccessExternalNetwork
Eg:Contentprovider
Headend
Video encoder/multiplexer
First hoprouter
IGMPv3proxy routing
IGMPv3snooping
IGMP:{Limits}
{Static-fwd}PIM-SSMPIM-SSM
L3 Transport Options in clouds:Native: PIM-SSM or MVPN/SSM
MPLS: LSM / mLDP RSVP-TEOpt.
SourceRedundancy
Content injection:External, national, regional, local
Dis.Edge Rtr
IGMPv3SSM
PIM-SSM
Same choices for all access technologies Different by access technology
?
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 18
Transit Transport design options
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 19
Transit technologies for IPTVSummary / recommendations
Native PIM-SSM + RPF-VectorMost simple, most widely deployed, resilient solution.
MVPN-GREAlso many years deployed (Cisco/rosen specification). Recommended for IPTV when VRF-isolation necessary !
mLDPRecommended Evolution for MPLS networks for all IP multicast transit:
‘Native’ (m4PE/m6PE) ‘Direct-MDTMVPN-mLDP’ (IPv4/IPv6)
RSVP-TE P2MPStrength in TE elements (ERO/CSPF + protection)Recommended for limited scale, explicit engineered designs, eg: IPTV contribution networks.
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 20
OverviewElements of transport architecture for tree building• C(ustomer)-tree building protocols
IPTV: IGMPv3 / PIM-SSM• P(rovider)-tree (PMSI) building protocols
Native: PIM-SSM/SM/Bidir, MPLS: mLDP, RSVP-TE• PE mapping: C-tree(s) to P-tree
1:1/N:1 (aggregation) ; ‘native’/VPN (L2, L3) ; static/dynamic• PE-PE (“overlay”) tree signaling protocols
Optional PIM or BGP (extensions)Not needed: native IPv4/IPv6, ‘direct-MDT’ mLDP, static mapping
PE1 P1
PE2 CE2P2
P4 PE3 CE3Upstream PE =Headend LSR
Tailend LSRs =Downstream PEsCE2
Content Content SourceSource
ReceiverReceiver
ReceiverReceiver
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 21
Content Content SourceSource
PE-1
PE-2
PE-3
P-4CE-1
CE-2
CE-3
MPLS Core
ReceiverReceiver
ReceiverReceiver
IPv4IPv6
IPv4IPv6
IPv4IPv6
MPLS traffic forwarding
L100
“Push”
MC Pkt L20
L30
“Swap”
“Pop”
Same forwarding (HW requirements) with mLDP / RSVP-TE
Initial: “Single label tree” for both non-aggregated & aggregated
No PHP: receive PE can identify treePut packet after pop into correct VRF for IP multicast lookup
MC Pkt
MC Pkt
MC Pkt
MC Pkt
MC Pkt
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 22© 2006 Cisco Systems, Inc. All rights reserved.
Content Content SourceSource
PE-1
PE-2
PE-3
P-4CE-1
CE-2
CE-3
MPLS Core
ReceiverReceiver
ReceiverReceiver
IPv4
mLDP signalingwith native and Direct-MDT
IPv4
IPv4
PIM-V4 JOIN: VRF IPTVSource= 10.10.10.1Group = 232.0.0.1
PIM-V4 JOIN: VRF IPTVSource= 10.10.10.1Group = 232.0.0.1
PIM-V4 JOIN: VRF IPTVSource= 10.10.10.1Group = 232.0.0.1
PIM-V4 JOIN: VRF IPTVSource= 10.10.10.1Group = 232.0.0.1
mLDP Label Mapping:FEC = S+ G+RD+ RootLabel=(20)
mLDP Label Mapping:FEC = S+ G+RD+ RootLabel=(20)
mLDP Label Mapping:FEC = S+G +RD+RootLabel=(100)
mLDP Label Mapping:FEC = S+G +RD+RootLabel=(100)
PIM-V4 Join: VRF IPTVSource= 10.10.10.1Group = 232.0.0.1
PIM-V4 Join: VRF IPTVSource= 10.10.10.1Group = 232.0.0.1
mLDP Label Mapping:FEC= S + G + RD + RootLabel=(30)
mLDP Label Mapping:FEC= S + G + RD + RootLabel=(30)
P2MP LSP“Root”
VRFIPTV
VRFIPTV
VRFIPTV
FEC: Forwarding Equivalency Class
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 23
Content Content SourceSource
PE-1
PE-2
PE-3
P-4CE-1
CE-2
CE-3
MPLSCore
ReceiverReceiver
ReceiverReceiver
IPv4
RSVP-TE P2MP signalingwith static native IPv4 to customer
IPv4
IPv4
PATH P4, PE2PATH P4, PE2
P2MP LSPHeadend
Static IGMP/PIM joinSource= 10.10.10.1Group = 232.0.0.1On interface to CE
Static IGMP/PIM joinSource= 10.10.10.1Group = 232.0.0.1On interface to CE
Static IGMP/PIM joinSource= 10.10.10.1Group = 232.0.0.1On TE tunnel interface
Static IGMP/PIM joinSource= 10.10.10.1Group = 232.0.0.1On TE tunnel interface
Static IGMP/PIM joinSource= 10.10.10.1Group = 232.0.0.1On interface to CE
Static IGMP/PIM joinSource= 10.10.10.1Group = 232.0.0.1On interface to CE
TE tunnel config:ERO1: P-4, PE-2ERO2: P-4, PE-3
TE tunnel config:ERO1: P-4, PE-2ERO2: P-4, PE-3
PATH P4, PE3PATH P4, PE3
PATH P4, PE2PATH P4, PE2
RESV Label = 20RESV Label = 20
RESV Label = 30RESV Label = 30
RESV Label = 100RESV Label = 100
RESV Label = 100RESV Label = 100
Label merge !Assign same upstream labelFor all branches of a tree
Label merge !Assign same upstream labelFor all branches of a tree
PATH P4, PE2PATH P4, PE2
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 24
Virtualization considerations“Internet/Walled-garden” or L3VPN ?
L3VPN (MVPN) developed as multicast component of (unicast/RFC2547) L3VPN
Primarily for “Enterprise VPN” servicesUsable for IPTV as well (with MVPN-GRE or MVPN-mLDP)
Why ?Core - operator policy for all services (VPN, IPTV, Internet, …)Edge - wholesale considerations (VPN per wholesaler)
Service separation considerations (service per VPN)
Use only when needed !Native IP multicast with PIM-SSM or mLDP most simple! L3VPN adds complexity, convergence, reliability considerations.No need for L3VPN for access control policy reasons!
All possible with native IP SSM access control
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 25
L2VPN considerations
L2 preferred by non-IP ‘communities’IP address transparency (unicast only issue)
PE “invisible” = customer free to choose protocols independent of provider
Not true if PE uses PIM/IGMP snooping!
No (dynamic) P/PE L2 solution with P2MP treesVPLS: full-mesh/hub&spoke P2P pseudowire only
Non P/PE models available: single-hop protected pseudowires.
Recommended directions:TBD: Define how to use mLDP for L2VPN (VPLS)
Most simple: one mLDP MP2MP LSP per L2VPN (broadcast)
Recommend not to use IGMP/PIM snooping on L2VPN-PE!
Unless customer is provider (eg: broadband edge design)
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 26
Broadband edge IP multicast
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 27
End-to-end protocol viewDSL, L3 aggregation
PIM-SSM (S,G) joins IGMPv3 (S,G) membership
STBHomeGateway
Eg:DSLAMPE-AGG
Core Distribution/ regional
Aggregation Home NetAccessExternalNetwork
Eg:Contentprovider
Headend
Video encoder/multiplexer
First hoprouter
IGMPv3proxy routing
IGMPv3snooping
IGMP:{Limits}
{Static-fwd}PIM-SSMPIM-SSM
L3 Transport Options in clouds:Native: PIM-SSM or MVPN/SSM
MPLS: LSM / mLDP RSVP-TEOpt.
SourceRedundancy
Content injection:External, national, regional, local
Dis.Edge Rtr
IGMPv3SSM
PIM-SSM
Same choices for all access technologies Different by access technology
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 28
End-to-end protocol viewDSL, L2 aggregation
PIM-SSM(S,G) joins IGMPv3 (S,G) membership
STBHomeGateway
Eg:DSLAMPE-AGG
Core / Distribution Aggregation Home NetAccessExternal
NetworkEg:
Contentprovider
Headend
Video encoder/multiplexer
First hoprouter
IGMPv3proxy routing
IGMPv3snooping
IGMP:{Limits}
{Static-fwd}PIM-SSM
TransportOptionsOpt.
SourceRedundancy
Content injection:External, national, regional, local
IGMPv3SSM
Same choices for all access technologies Different by access technology
L2
IGMPv3snooping
IGMPv3snooping
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 29
End-to-end protocol viewdigital cable (non DOCSIS)
PIM-SSM (S,G) joinsIGMPv3 (S,G) membership
CableSTB
Eg:DSLAMPE-AGG
Core Distribution/ regional
Aggregation Home NetAccessExternalNetwork
Eg:Contentprovider
Headend
Video encoder/multiplexer
First hoprouter
IGMP:{Limits}
{Static-fwd}PIM-SSMPIM-SSM
L3 Transport options in clouds:Native: PIM-SSM or MVPN/SSM
MPLS: LSM / mLDP RSVP-TEOpt.
SourceRedundancy
Content injection:External, national, regional, local
Dis.Edge Rtr
IGMPv3SSM
PIM-SSM
Same choices for all access technologies Different by access technology
eQAM HFC
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 30
Aggregation
End-to-end protocol viewDOCSIS 3.0 cable
PIM-SSM (S,G) joinsIGMPv3 (S,G) membership
IP/CableSTB
Eg:DSLAMPE-AGG
Core Distribution/ regional
Home NetAccessExternalNetwork
Eg:Contentprovider
Headend
Video encoder/multiplexer
First hoprouter
IGMP:{Limits}
{Static-fwd}DOCIS CLIPIM-SSMPIM-SSM
L3 Transport options in clouds:Native: PIM-SSM or MVPN/SSM
MPLS: LSM / mLDP RSVP-TEOpt.
SourceRedundancy
Content injection:External, national, regional, local
Dis.Edge Rtr
IGMPv3SSM
PIM-SSM
Same choices for all access technologies Different by access technology
HFCCMTS
CM/(eRouter)
DOCSIS 3.0MulticastSignalingDSID/DSx
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 31
Auto Multicast Tunneling (AMT)Tunnel through non-multicast enabled network segment
Draft in IETF ; Primarily for SSMGRE or UDP encapRelay uses well known ‘anycast’ address
Difference to IPsec, L2TPv3, MobileIP, …Simple and targeted to problemConsideration for NAT (UDP)Ease implemented in applications (PC/STB) (UDP)
Variety of target deployment casesRelay in HAG – provide native multicast in homeGateway in core-SP – non-multicast Access-SPAccess-SP to Home - non-multicast DSLIn-Home only – eg: multicast WLAN issues
Nonmulticast
multicastcapable
AMT GatewayAMT Gateway
AMT RelayAMT Relay
AMT TunnelAMT Tunnel
Nonmulticast
HAGNAT
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 32
ResiliencyMoFRR/Live-Live
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 33
live-live with path diversityprinciplesGuarantee:
Transfer two copies of stream path separated - No single failure in network impacts both copies
Best: Two networktraditional finance deployment
Cheaper: Shared networkNatural diversity (ECMP, …) [MoFRR ECMP]Forced diversity (various solutions)
Splice and Join at EDGE of network (or segment)In actual source/receiversIn network devices (dedicated or in router)No need for time-critical operations in core
Live-live service:receive/deliver two copies, splice/join on customer side. Limited to customers whose app/equip. can support this
MoFRR/Zero-loss service:Splice/join within service – applicable to all customers.
Src…
Naturallyor
forceddisjoint
…Rcv
Protection D
omain
SourceOr
streamsplicer
ReceiverOr
streamjoiner
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 34
Basic MoFRRECMP, IGP upstreamJoin within network device (router) by switching which received copy to forward.
Switch is not zero loss – but (close to) 50msec
R1 MoFRR operationsExpect two RPF paths (from IGP/BGP)
ECMP Join to both RPF interfacesForward traffic from one of them.If used path is lost, switch to second
Various extensions consideredSwitchover based on traffic lossFull zero-loss (sequence number based join)Support for more topologies:
U-turn via LFA
Src
R1
RU1 RU2
Naturallydisjoint
Rcv
RH
Protection D
omain
R1a R1bU-turn attachment
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 35
Application side resiliency
FEC – Forward error correctionCompensate for statistical packet loss
Use existing FEC eg: for MPEG transport to overcome BER errors. Potentially applicable to sub 50 msec correction.
ARQ - RetransmissionsDone eg: with Cisco VQE – unicast retransmissions
Candidate large bursts of retransmissions
Multicast retransmissions would help improve
FEC/ARQ introduce delay !
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 36
Failure impact upon viewer experience
Very hard to measure and quantifyIf I frames or frame-information is lost, impact will be for a whole GOP
GOP can be 500 msec (MPEG2) ... 10 sec (WM9)
Viewing impact beyond single GOP possible!Encoding and intelligence of decoder to “hide” loss impact quality as wellIPTV STB typically larger playout buffer than traditional non-IP STBs:
Loss can cause catch-up: no black picture, but just a jump in the motion.
What “viewing” loss is acceptable ?Measured in #phone calls from complaining customers !?Standard: 1 artefact in two hours.
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 37
Admission control
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 38
Static vs. dynamic trees
1. “Broadcast Video”Dynamic IGMP forward up to DSLAM
DSL link can only carry required program!
static forwarding into DSLAM
Fear of join latency
History (ATM-DSLAM)
2. “Switched Digital Video”Allow oversubscription of PE-
AGG/DSLAM link
3. “Real Multicast”dynamic tree building full path
Source
HomeGateway
DSLAM
PE-AGGStat
ic (P
IM) t
ree
(1)
Stat
ic (P
IM) t
ree
(2)
IGM
P jo
ins
PIM
join
s
(3)
IGM
P jo
ins
IGM
P jo
ins
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 39
Switched Digital VideoWhy oversubscription of access links makes sense
Switched Digital VideoConsider 500…1000 users on DSLAMConsider 300 available TV programsMonitor customer behavior – what is being watched ?
Example (derived from actual MSO measurements)Some 50 TV programs almost always watched (big channels)Out of remaining 220 TV programs never than ¼ watched Never need more bandwidth than ~ 125 channels!
Dynamic joining towards core ?Todays offered content << #users aggregated -> worst case traffic will always flow.More a provisioning issue – and when content expands well beyond current cable-TV models
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 40
Admission control
Congestion must be avoidedInelastic: TV traffic can not throttle upon congestion
One flow too many disturbs all flows
Need to do per TV-flow admission control
Router-linksRouter local CLI solution
Strategic solution: RSVP
Already used for unicast VoD
Can only share bandwidth between unicast and multicast with RSVP
Broadband access (DSL link, Cable)Issues with L2 equipment (eg: DSLAM)
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 41
3. Fair sharing of bandwidth1GE
Multicast Call Admission Control
1GE
1GE
250-500 usersper DLAM
DSLAM
DSLAM
DSLAM
Cat7600
Example CAC use:
4. 250 Mbps for each CP250 Mbps Internet/etc
1. Three CPs
10GE
10GE
10GE
ContentProvider 1
ContentProvider 2
ContentProvider 3
ContentProviders
ServiceProvider
PayingCustomers
2. Different BW:
- MPEG2 SDTV: 4 Mbps - MPEG2 HDTV: 18 Mbps - MPEG4 SDTV: 1.6 Mbps - MPEG4 HDTV: 6 Mbps
MPEG4 SDTV
MPEG2 SDTVMPEG4 SDTV
MPEG2 HDTV
MPEG4 SDTV
MPEG2 SDTVMPEG4 SDTV
MPEG2 HDTV
MPEG4 SDTV
MPEG2 SDTVMPEG4 SDTV
MPEG2 HDTV
CP-1 (250Mbps)
CP-2 (250Mbps)
CP-3 (250Mbps)
Voice/Int/V
oD (250Mbps)
5. Simply add global costs
PE
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 42
Channel changing
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 43
Join Latency
Static forwarding (to PE-AGG, or DSLAM) To avoid join latencySometimes other reasons too (policy, …)
Bogus ?Hop-by-hop Join latency (PIM/IGMP) very low, eg: individual < 100 msec …Joins stop at first router/switch in tree that already forwards treeProbability for joins to go beyond PE-AGG very low !
If you zap to a channel and it takes ¼ sec more: You are the first guy watching this channel in a vicinity of eg: 50,000 people. Are you sure you want to watch this lame program ?
ImportantTotal channel zapping performance of system – Primetime TV full hour or (often synchronized) commercial breaks.Join latency during bursts might be worse than on average. (DSLAM performance)
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 44
Channel ChangingGOP size and channel changing
GOP size of N seconds causes channel change latency
USER OUTAGE EXPERIENCE>= N secondsCan not start decoding before next I-frame
GOP sizes > 0.5 sec required ?
Codec dependencies:How much bandwidth is saved in different codecs by
raising GOP size but keep the quality.
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 45
Video Quality Experience
Three functions (currently): Video Quality monitoring, FEC/ARQ support for DSL links, Fast Channel changeUses standards RTP/RTCP, FEC extensions.Fast channel channel by RTCP “retransmission” triggered resend of missing GOP packets from VQE (cached on VQE).
STBHomeGatewayDSLAM
PE-AGG
Core Distributionregional
Aggregation Home NetAccess
ASERVER VQE
multicast
Unicast/(multicast)
control
VQE Clientlibrary
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 46
Summary
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 47
Multicast and IPTVSummary
Design IP multicast WITH SSM as generic infrastructure service –for IPTV and beyondSelect transport design
Native IP multicast or mLDP (MPLS core) for most networksRSVP-TE P2MP for eg: contribution network
Understand your L2 broadband edge specificsIGMPv3 snooping and SSM + lots of options
Determine appropriate resilience supportPath selection
ECMP and multicast or multiple topologiesAdmission control
Router local and broadband specificChannel changing
GOP size, total performance
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 48
Q and A
© 2007 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialSession IDPresentation_ID 49