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Architectures and Technologies for Optimizing SP Video Networks
- 1. Architectures and
Technologies for
Optimizing SP Video
networks
Rajesh Rajah
Consulting Engineer
Cisco Systems
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 1
- 2. Session Objectives
At the end of the session, the participants
should be able to:
Understand the trends for video in the SP Industry
Provide a high level End-to End system architecture
Understand the possible architectures and
technologies for Video transport
Understand of Network-to-Video-layer linkages that
enable optimized Video transport
Provide a deep dive on key mechanisms and
technologies to enhance and monitor Video quality
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 2
- 3. How do you get your TV today ?
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 3
- 4. What is IPTV?
IPTV = IP network delivered TeleVision
Today it usually includes:
Broadcast channels/Switched Digital Broadcast (SDB)
Video-on-Demand services (VOD)
Digital Video Recorder services (DVR/PVR)
Interactive TV applications (ITV)
Broadband IP
Access Network
Today: xDSL, Cable Modem, IP-STB Analog or Digital TV
FTTx, Carrier Ethernet, Subscriber (Set Top Box) (increasingly HDTV)
Future?: 3G, WiMax, ...
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 4
- 5. IPTV Architecture – View from space
“Glass to glass” experience
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 5
- 6. Delivery Networks with IP as Underlying
Transport
Satellite XM-, L-, S-, K-Band…
Regional Local Access
HE/VHO
National Content Servers/
Content Portal DVB-H
Local/Regional
WAN Content WiMax
Rcv, Enc HSDPA
WAN Radio Tower
Mux,Encap,
Stream Mobile EVDO
Local Access
ILEC-VSO DSLAM
Receive, Encode
Mux, Encapsulate
IPmc VQE
CORE DISTRIBUTION AGGREGATION Wireline
Local Access
Content
Servers
MSO-Hub
Super HeadEnd
(SHE)
Mux EQAM
Rcv, Enc
Mux,Encap, Cable
Stream Regional Local Access
HE/VHO
Local/Regional
Content
Content HFC NET
Servers/Portal
WAN
CORE DISTRIBUTION AGGREGATION ACCESS
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 6
- 7. To IP network as
MPEG/UDP/IP multicast stream.
MPEG/RTP/UDP/IP Encrypted
Analog or Analog or MPEG
Digital Digital
Encrypted
MPEG
Local
Compress and encode
Affiliate
one channel
Ad Splicer will take
programming in
Demodulate and in the multicast
MPEG-2 or 4; SD, HD
demultiplex TV signals. stream and insert
and/or PiP. Output is IP
Local channels include new ad content and
multicast stream.
PEG (Public, output two streams
Educational, with the same
Government) channels. Multicast address,
but different source
addresses.
Middleware is the ‘brain’
of an IPTV network. It
includes:
- Electronic Program
Guide To IP network as
- Entitlement System VoD Servers store video unicast streams.
- Asset Distribution assets. The Middleware with
- Navigation Server the Entitlement system,
It communicates with Session Manager On demand
all set top boxes manager, Policy Server for
CAC, and video pump enable
Encrypted MPEG
Used by both broadcast the streaming of programs.
and VoD
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 7
- 8. Next Generation Video Service Trends
Driving network and in-home architectures…
More HD Channels
Massive VoD Libraries
Time Shifted TV
Internet Video
Any Stream to Any Screen
Targeted Advertising
Next Generation User Interfaces
Service Velocity
3DTV
“The vision is to give our customers the ability to watch ANY movie, television show, user
generated content or other video that a producer wants to make available On Demand”
– Brian Roberts, CEO Comcast – CES 2008
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 8
- 9. Evolution to IP Video
Unified experience and enhanced monetization
Traditional Cable – 1st Wave IPTV – 2nd Wave IP Video – 3rd Wave
On-net only On-net only On-net or Off-net
TV TV TV, PC, mobile
Limited service velocity Higher service velocity Highest service velocity
Business Model: B2C Business Model: B2C Business Model: B2B2C
More Open, More Flexible, More Monetization Opportunities
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 9
- 10. 3rd Wave Drives Infrastructure Requirements
Internet Content Personal 3rd Wave Video
Requirement
(Hulu, Netflix) Media (YouTube) (including Time-Shift TV)
Live, VoD, Interactive, Live, Time-shift, VoD,
Services Social
VoD, Interactive, Social
Interactive, CDN Ready
M Copies : N Subs 1 Copy : N Subs 1 Copy : N Subs
Usage / Devices PC, some mobile PC, some mobile STB, PC, Mobile
Ingest Feeds Scale / 10s, 1,000s, 100s, Real-time and Non real
Performance Non real-time Non real-time time
10-20K Titles, 100M+ Titles 100K Titles
Storage Scale /
10s of Terabytes, Petabytes, 100s of Terabytes
Resiliency Med Resiliency Low Resiliency High Resiliency
Ingest : Playout 1 : 10,000s 1 : < 10 1 : 10,000s
Streams Scale 10,000s Millions 100,000s
Latency Tolerance High (secs) High (secs) Low (<1 sec)
HTTP, MS, Adobe MPEG, H.264, Internet Content
File Formats / Protocols Adaptive Emerging
HTTP, MS, Adobe
Ready
File Sizes, Small to Med, Small, Large,
Caching Benefits High Caching Low Caching High Caching
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 10
- 11. IP Video Solution – 3rd Wave
High Level Functional Areas
Video
Datacenter
Unified
CompuVng
Service
PlaXorm
ApplicaVon
Servers
Backoffice
Security
PlaXorm
• Session
and
Resource
Management
• RUI
HosVng
• Billing
• DRM
• Metadata
• ApplicaVon
Services
• EnVtlement
• License
Servers
• Content
Management
• Security
OperaVons
• AdverVsing
Content
Ingest
and
Transport
Edge
Network
CPE
/
So(ware
/
UI
/
Apps
• IP
Edge,
QAM
and
HFC
• Home
Gateway
• FTTH
• STBs
• xDSL
• PCs
• On-‐Net
and
Off-‐Net
• Game
Consoles
• Mobile
Phones
Encoding
Content
Delivery
Network
• H.264
Encoding
• Library
Server
• MP4
Wrapping
• Caching
Gateway
• Internet
Streamer
Linear
/SDV
• Splicing
• Grooming
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 11
- 12. IP Video Solution - 3rd Wave
Functional Blocks, Components, and Flows
Video
Datacenter
Unified
CompuVng
Service
PlaXorm
ApplicaVon
Backoffice
/
Billing
Security
/
DRM
PlaXorm
SRM
Servers
PATH
BSS/
DRM
Discovery: EnVtlement/
Navigation IdenVty
Service
Ad
Decision
ApplicaVon
Policy
and
Router
System
Router
Server
Selection
Content
Ingest
and
Transport
Edge
Network
CPE
/
So(ware
/
UI
/
Apps
(IP
Edge,
QAM
and
HFC)
Off-‐Net
OpVon
Video
Management
Internet
File-‐based
OnDemand
Assets
STB/PC
with
and
Linear
Programs
player
Encoding
Content
Delivery
Network
Home
Network
CDN
CCPH
C2
IPSTB
with
player
H.264
Encoder
and
Content
Cache
Internet
MP4
wrapping
Library
Nodes
Streamer
PC
with
player
Linear
/SDV
HFC
Home
Gateway
Game
Console
Splicer/
Groomer
Mobile
Phone
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 12
- 13. Broadcast Media Content Delivery Architecture
Key Building Blocks
Transport Post Production Primary Content Adquisition Secondary
Production Consumption
& Playout Distribution & Signal Processing Distribution
Direct to Home Headend
Post Production
Over the Air Headend
News Gathering
IP IP
MWP
Headend Home Connected
Telco
Core Gateway
Home
Network IP IP
Network
Studio-to-Studio
Cable Headend
Video Data Center IP
Sport Events Broadband CDN
IP IP IP
Network
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 13
- 14. Video Service Providers: Taxonomy & Characteristics
Higher bw streams More end points
Uncompressed, Lossless
Very High bit-rate stream: SD Compressed
(270Mbps), HD (1.5-3Gbps) Compressed
Low/moderate bit-rate streams ~
P2P and P2MP same as or similar to secondary dist Low bit-rate streams: SD (3-4Mbps
(unicast and multicast) MPEG2, 2-3Mbps MPEG4), HD
P2P and P2MP
(unicast and multicast) (16-20Mbps MPEG2, 6-10Mbps
P2MP MPLS focused MPEG4)
e.g. BT M&B, RAI MPLS & IP technology
P2P for VOD (unicast) & P2MP for
e.g. Contribution providers, US IPTV & CATV (multicast)
national backbones
MPLS & IP technology
e.g. DT, FT, Comcast, …
Studio
Stadium Final
Studio
Home
Network
IP/MPLS
Core IP/MPLS
Core IP/MPLS
Mobile
Studio
Core Access and
Fixed
Studio
Aggregation
DCM
VOD content
CDS distributing to scale CDS
DCM VQE
National Local
Content Super Head Head VSOs Homes
Content
Insertion End (×2) Insertion End (×2) (×100s) × millions
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 14
- 15. Video Transport Services in the SP Video Ecosystem
Increase number of end points
Production Contribution Post Production Distribution Consumption
Primary Secondary
Increase Bandwidth and SLA Requirements
Direct To Home
News Headend
Gathering Telco
IP
Headend
Studio to Ingest Cable
Studio Core IP
Network IP
Headend
Mobile
Sport Video Data
Events Center IP IP
Contribution Service Primay Distribution Service Secondary Distribution Service
Studio to Studio Content origination to Provider Provider to Consumer
Uncompressed Compressed Compressed
Very High bit-rate Low to high Low to Moderate bit-rate
Unicast and Multicast Unicast and Multicast Unicast and Multicast
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 15
- 16. Access Independence
One headend, one IP network
Multiple access networks, Multiple screens
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 16
- 17. Video-to-Network
layer Linkages
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 17
- 18. IP Video / IPTV Solution
Network to Video layer Linkages
Network Layer
Video Service Video Service
Unicast, Multicast Assurance & Network
Performance (QoS, QoE Resiliency against
and Scalability monitoring etc) failures, DoS attacks
Admission Control
Visual Quality
Video Service
of Experience (VQE)
Bandwidth
Error Repair, RCC Management
Video Application Layer
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 18
- 19. Video is very Susceptible to Loss
Single packet loss may result in an
impairment (unlike voice)
Loss of different packet types result
in different types of visual impairment
QoE is measured subjectively, eyes Slice error
of the viewer
General definition for QoE:
Impairments/time
Mean Time Between the Artefacts
Common industry benchmark Pixelisation
MTBA = 2 hrs or greater
No more than 1 error in a 2 hour movie
Other metrics such as number of
support calls may also be important
Ghosting
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 19
- 20. MPEG: Impact of packet loss
Impairment depends on which MPEG frames lost
I-frame loss will result in a visual impairment
Limiting loss to a single I-frame in the worst case will limit the level of impairment
Detailed paper at http://www.employees.org/~jevans/videopaper/videopaper.html
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 20
- 21. What is the most efficient way to control loss?
Cost / Complexity Tradeoff
Range of viable
Causes of packet loss: engineering options
Complexity
may vary by type of
Cost and
Excess Delay video distribution,
service or content
Prevent with QoS (i.e., Diffserv)
Congestion Number of possible
Prevented with Capacity planning, approaches, or
combinations of
QoS and CAC approaches.
PHY-Layer Errors (in the Core)
Insignificant compared to losses
due to network failures
Loss
Network Reconvergence (Impairments/Time)
Potential Over-
Engineering
Viable-
Re-engineering
Engineering
Required
Reduce with high availability (HA)
techniques and smart engineering
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 21
- 22. Services Comparison and Requirements
Services/ Video-on-Demand
Broadcast Video Internet Data
Attributes (VoD)
Transport Multicast Unicast Unicast
VLAN-per-DSLAM for
Common Video VLAN Common Video VLAN
Internet subscriber. L2
Service termination on the U-PE. termination on the U-PE.
Point-to-point
Separation IGMP/PIM-based multicast L3 routing between VoD
Pseudowire from U-PE
control flow server and U-PE
to BRAS
OSPF FC, BFD, Multicast OSPF FC, BFD, MPLS
OSPF FC, BFD, MPLS
Convergence FC, MPLS TE FRR (Routed TE FRR
TE FRR
PW)
Addressing Private IP addressing Private IP addressing Public/Private IP addr
CPE STB STB PC/Laptop
Access control IGMP profiles/white-lists Middleware/VoD server BRAS
Off-path, RSVP-based
Admission IGMP state limits On-path CAC, or BRAS
control Integrated CAC
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 22
- 23. Services Comparison and Requirements - continued
Services/ Video-on-Demand
Broadcast Video Internet Data
Attributes (VoD)
Separate Video Queue
Separate Video Queue with
QoS Priority with Higher priority than Best effort
Higher priority than VoD
VoD
-6 -6
Acceptable 10 (one artifact per 2-hr 10 (one artifact per 2-hr
NA
Packet drop rate movie) movie)
Latency (RTT) <200ms <200ms NA
requirements
Jitter <50ms <50ms NA
requirements
QoS WRED No No Yes
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 23
- 24. Video/IPTV Optimized Transport System
Primary challenges
The Primary Technology Challenges are common across
Distribution and Contribution
1. Basic transport
How to shift the packets … IP or MPLS, native or VPN?
2. Video service SLA
How to ensure that the IP / MPLS network delivers the required
SLAs
Number of potential deployment models and technology
approaches
Specific focus on controlling loss
Ultimate Goal: Lossless Transport
3. Service Monitoring and Management
How to verify that the IP network is delivering the required SLAs
for video, and to identify problem areas
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 24
- 25. Transport options – IP/MPLS
For non-multicast traffic and point to point feeds:
Native IP or MPLS. L3VPN, P2P TE, etc
For multicast, multipoint topologies:
– IP IP mVPN
– Native (PIM SSM) Multicast
P2MP TE
MPLS
– mVPN (LSM)
MLDP mVPN
– LSM (Label Switched Multicast)
– P2MP TE global
– PW over P2MP TE
– mLDP
• mLDP global
• mLDP + mVPN
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 25
- 26. Requirements Comparisons for Multicast Based
Services running on a Converged IP network
Video Contribution Secondary Managed
Distribution Enterprise mVPN
PIM mode SSM only SSM only SM and SSM
Sources per multicast 1 or 2 1 or 2 1 or 2
group
Multicast Group scale < 1000 < 1000 100s (S, G) per
VPN; 100s of VPNs
Receivers per Group <10 Millions 100s of sites;
potentially 1000s
Multicast Tree dynamism 100s of new trees per day; Static trees Trees are dynamic;
trees static once joins and leaves
established may impact core
Admission control and Yes No No
Bandwidth Reservation (time limited
reservations)
Fast ReRoute Yes Yes Yes
Offload routing Yes No No
Path diversity Yes Yes Yes
mVPN requirement ? For wholesale Yes
services
p2mp or mp2mp? p2mp p2mp mp2mp
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 26
26
- 27. Mapping of Multicast Service Requirements to
p2mp technology choices
Characteristic Plain IP p2mp MPLS TE mLDP
Multicast
Convergence
< ~500ms ~50ms < ~1s
Offload routing
IGP metric based IGP metric based
traffic engineering traffic engineering
Path separation
MoFRR or MTR MoFRR or MTR
Admission
control and bw
reservation
RSVP
Scalable mp2mp
MVPN
Presentation_ID
C25-452149-02 © 2007 Cisco Systems, Inc. All rights reserved.
2008 Cisco Confidential
Cisco Confidential 27
- 28. PIM Source Specific Mode (SSM)
Encoder
Result: Shortest path tree rooted
at the source, with no shared tree.
A B C D Middleware
E F
STB
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 28
- 29. Advantages of SSM
Very Simple – Easy to implement, maintain & troubleshoot
No RP/MSDP configs
No SPTswitchover/thresholds
Simpler control plane between independent PIM domains
More Secure
Sources are known in advance
Only one source can send to the SSM channel
Prevention of DOS attacks from unwanted sources
More Scalable and Flexible
Support for both IPv4 and IPv6 addresses
SSM for IGMPv3 clients, SSM-Mapping for IGMPv2 clients
Flexibility for Static or DNS-based Mapping in case of SSM Mapping
Dissimilar content sources can use same group without fear of interfering
with each other (although not recommended for IPTV deployment)
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 29
- 30. End-to-end protocol view – Layer3 Agg
Same choices for all access technologies Different by access technology
Video Core Distribution Aggregation Access Home Network
Headend / regional Eg:
PE-AGG
DSLAM Home STB
Gateway
PIM-SSM (S,G) joins IGMP membership
Video Stream
L3 Transport Options in clouds:
Native: PIM-SSM or MVPN/SSM
Opt. MPLS: LSM / mLDP RSVP-TE IGMP:
{Limits} IGMP IGMP IGMP
Source
{Static-fwd} snooping Proxy
Redundancy PIM-SSM PIM-SSM PIM-SSM
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 30
- 31. End-to-end protocol view
digital (non DOCSIS) cable
Same choices for all access technologies Different by access technology
Video Core Distribution Aggregation Access Home Network
Headend / regional
PE-AGG HFC
Cable STB
eQAM HFC
PIM-SSM (S,G) joins
IGMP membership
Video Stream
L3 Transport Options in clouds:
Native: PIM-SSM or MVPN/SSM
Opt. MPLS: LSM / mLDP RSVP-TE IGMP:
{Limits} IGMP
Source
{Static-fwd} snooping
Redundancy PIM-SSM PIM-SSM PIM-SSM
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 31
- 32. End-to-end protocol view – Layer2 Agg
Same choices for all access technologies Different by access technology
Video Core Distribution Aggregation Access Home Network
Headend / regional Eg:
PE-AGG
DSLAM Home STB
Gateway
L2
access
PIM-SSM (S,G) joins IGMP membership
Video Stream
L3 Transport Options in clouds:
Native: PIM-SSM or MVPN/SSM
Opt. MPLS: LSM / mLDP RSVP-TE
IGMP: IGMP IGMP IGMP
Source IGMP
{Limits} snooping Proxy
Redundancy PIM-SSM snooping
{Static-fwd}
PIM-SSM
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 32
- 33. Network Resiliency
Video-to-Network layer
Linkages
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 33
- 34. Fast Convergence
- reduces affect of link outage (~ 500ms)
Primary
Stream
X
Video
Video
Source
Receivers
Rerouted
Core
Primary Edge
Distribution
Stream
Distribution
(DCM)
(DCM or VQE)
Implementation and protocol optimisations
Delivers sub second convergence times for unicast (OSPF, ISIS, BGP)
and multicast (PIM)
Available on all Cisco core and edge platforms
Lowest bandwidth requirements in working and failure case
Lowest solution cost and complexity
Is not hitless – will result in a visible artifact to the end users
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 34
- 35. Multicast-only Fast Reroute (MoFRR)
MoFRR provides the capability to instantiate resilient
multicast trees for the same content
If receive IGMP or PIM join on downlink and have multiple
paths to source send joins on two paths
Utilize IGP Link-State database and knowledge of how
networks are designed to ensure streams are path diverse
Feed connected receivers from only one of the two received
streams
Monitor the health of the primary stream and upon failure,
use the secondary
A simple approach from a design and deployment and
operations perspective = Receiver
= IGMP Join
MoFRR depends on natural spatial diversity of large
= PIM Join
networks, disjointed physical topology with dual edge to
= Source
dual core
Can be used for both loss and lossless approaches and
be implemented in the network or on the video end system
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 35
- 36. Mapping of Multicast Service Requirements to
p2mp technology choices
Characteristic Plain IP p2mp MPLS TE mLDP
Multicast
Convergence
~1s ~50ms ~1s
Offload routing
IGP metric based IGP metric based
traffic engineering traffic engineering
Path separation
MoFRR or MTR MoFRR or MTR
Admission
control and bw
reservation
RSVP
Scalable mp2mp
MVPN
Presentation_ID
C25-452149-02 © 2007 Cisco Systems, Inc. All rights reserved.
2008 Cisco Confidential
Cisco Confidential 36
36
- 37. Towards Lossless Video/IPTV Transport:
Deployment Scenarios
TE +
Live / Live
MTR
+ Live / Live
MPLS TE FRR
MPLS TE FRR
+ FEC or TR
MoFRR +
Live / Live
Fast
Convergence + MoFRR
FEC or TR
Fast
Convergence
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 37
- 38. Towards Lossless Video/IPTV Transport:
Deployment Scenarios Options where a lossless
solution is required and the
topology does not support
path diversity with MoFRR
Recommended approach
TE + where some loss is
Live / Live tolerable and topology
Recommended where supports MoFRR
lossless approach is • Lowest bandwidth
required and topology used in working and
supports path MTR failure cases
diversity with MoFRR + Live / Live • Lowest solution cost
• Lowest bandwidth and complexity
used in failure cases • Constrained impact of
• Low solution cost MPLS TE FRR network failures on
and complexity MPLS TE FRR
+ FEC or TR video
• Does not apply to
all topologies
MoFRR +
Live / Live
Recommended approach
where some loss is
Fast tolerable and topology does
Convergence + MoFRR
not support MoFRR
FEC or TR • Lowest bandwidth
used in working and
Fast failure cases
Convergence • Lowest solution cost
and complexity
• Constrained impact of
network failures on
video
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 38
- 39. IPv4 and IPv6 Multicast Comparison
Service IPv4 Solution IPv6 Solution
Addressing Range 32-bit, Class D 128-bit (112-bit Group)
Protocol Independent, All
Protocol Independent, All
Routing IGPs and MBGP with v6
IGPs and MBGP
mcast SAFI
PIM-DM, PIM-SM, PIM-SM, PIM-SSM,
Forwarding
PIM-SSM, PIM-bidir PIM-bidir
Group Management IGMPv1, v2, v3 MLDv1, v2
Domain Control Boundary, Border Scope Identifier
MSDP across
Single RP within Globally
Interdomain Solutions Independent PIM
Shared Domains
Domains
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 39
- 40. Multicast Feature Recommendations
Features / Platform Core Aggregation Aggregation Access Access
(N-PE/PE) (PE-AGG if L2 (PE-AGG if L3 U- (Layer3 U- (Layer2 U-
U-PE) PE) PE) PE)
PIM Sparse Mode
PIM SSM Mapping
(Static or DNS)
Multicast Loadbalancing
PIM Fast Hello
RPF Tuning
IGMPv2 Join/Leave
IGMP Snooping
IGMP Fast Leave
IGMP Tuning
ARP Timeout Tuning
(Optional) IGMP Static Joins
Multicast HA
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 40
- 41. Multicast Feature
Recommendations
Features / Platform VHE DSLAM Residential Gateway STB
(7600) (RG)
PIM Sparse Mode
PIM SSM Mapping
(Static or DNS)
Multicast Loadbalancing
PIM Fast Hello
RPF Tuning
IGMPv2 Join/Leave
IGMP Snooping
IGMP Fast Leave
IGMP Tuning
ARP Timeout Tuning
(Optional) IGMP Static Joins
Multicast HA
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 41
- 42. Quality of Service
Video-to-Network layer
Linkages
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 42
- 43. CE
CE Access Aggregation
Access Aggregation Edge
Edge Core Edge Access CE
U-PE Enterprise B
PE-AGG P
N-PE
10/100/ GE Ring Queuing 10/100/
• Egress Hub
Spoke 1000 Mpbs
1000 Mpbs • Congestion Avoidance
U-PE
Enterprise A
• Egress Queuing
N-PE
• Egress Queuing 10/100/
SONET/SDH
Hub N-PE 1000 Mpbs
Ring
P P Enterprise A
Spoke • Classification
• Policing
10/100/
1000 Mpbs
• Marking
U-PE N-PE
Enterprise B • Egress Queuing U-PE
Internet
• Marking
• Traffic Shaping
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 43
- 44. General QoS Guidelines
Do not mix UDP TCP traffic in the same class
Do not mix Voice Video traffic in the same class
Per-subscriber SLA for Voice and Data applications
Per-subscriber SLA not applicable for Video/IPTV
Over-the-top (Internet) Video traffic to be treated as
best-effort traffic
If Dual Priority queue is supported, then highest priority
is for Voice traffic. (Selective) Broadcast Video traffic
may be mapped to the lower priority in the Dual PQ.
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 44
- 45. QoS Guidelines for Video
Network SLAs
Delay: not critical. Most applications are unaffected
Jitter: not critical. IP-STBs can buffer 200 msec
Packet-loss: critical. Packet loss rate 10-6 (one noticeable artifact per hour of
streaming @ 4Mbps ). 1 video packet lost may lead to 500 ms of visible
artifacts.
Packet loss due to queue drops by bursts at aggregation points from
multiple sources (also number of hops, link occupation)
Queue depth sizing using probability analysis, so packet loss rate (e.g.
10-6) is below target
Single or Separate Video queue for Broadcast Video and VoD based
on BW requirements, No. of Queues, CBWFQ/WRR, No. of traffic
classes
Disable WRED for Video queue
Priority of Broadcast Video traffic higher than VoD traffic
Usually Broadcast Video traffic is not over-subscribed
Use VoD CAC during Insufficient Bandwidth conditions
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 45
- 46. Video optimised Diffserv Schedulers
Cisco leads the R
Strict
priority queue
industry in the EF #1
B
development and
Policer Tail Drop
support of multi-
priority schedulers R Bandwidth queue
EF #2
implementations B
Tail Drop
Enables Classifier
Policer
Scheduler
differentiation Bandwidth queue
between premium
AF #1
services, requiring RED
bounded delays Bandwidth queue
AF #n
RED
Classifier Per-class policy
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 46
- 47. Video optimised Diffserv Schedulers
With Cisco’s optimised IP
Diffserv implementations,
worst-case per hop delays
1ms for high-speed
links
End-to-end jitter of 1ms
is realiseable today with
Cisco’s video optimised
products
References:
Clarence Filsfils and John Evans, Deploying Diffserv in IP/MPLS Backbone
Networks for Tight SLA Control, IEEE Internet Computing*, vol. 9, no. 1, January
2005, pp. 58-65
http://www.cisco.com/en/US/prod/collateral/routers/ps167/prod_white_paper0900aecd802232cd.pdf
John Evans, Clarence Filsfils, “Deploying IP and MPLS QoS for Multiservice
Networks: Theory and Practice”, Morgan Kaufmann, ISBN 0-123-70549-5.
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 47
- 48. Service Availability
Network availability is the fraction of time that network
connectivity is available between a network ingress point
and a network egress point.
For video, however, simply having connectivity is not
enough, hence service availability is often a more
meaningful metric.
Service availability is a compound metric, defined as the
fraction of time the service is available between a specified
ingress point and a specified egress point within the bounds
of the other defined SLA metrics for the service, e.g. delay,
jitter, and loss.
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 48
- 49. Five 9s Availability
Five 9s availability assured through
Selecting carrier class network elements with high MTBF and low MTTR
Ensuring that the network design is resilient with no single points of failure (links, nodes
or shared risks), employing redundancy in both network elements and links.
Using IP and MPLS fast convergence and fast reroute technologies, with fast failure
detection techniques (e.g. IPoDWDM) to minimise packet loss from network element
failures
Employing high-availability techniques (e.g. NSF, SSO, ISSU) to minimise the impact
from route processors upgrades or failures.
Using Diffserv QOS, admission control and capacity planning to ensure that the SLA
requirements can be met
Using transport and application level approaches to recover from any loss experienced,
and hence provide lossless transport
Use a “closely coupled” service management solution, to rapidly isolate and identify
service impacting faults when they occur.
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 49
- 50. Example
IPTV DiffServ QOS Domain
Core /Edge/ Aggregation Access UNI
Traffic Class MPLS/IP Ethernet DSL, ETTX DSL WiMAX
PHB DSCP MPLS EXP 802.1P 802.1P ATM 802.16
Control Protocols
AF 48 6 (6) (6) VBR-nrt nrtPS
Network Management
Residential Voice
EF 46 5 5 5 VBR-rt rtPS
Business Real-time
VBR-nrt
Residential TV and VoD AF 32 4 4 and 3 4 NA
Business Critical In Contract 16 2 2
AF 2 and 1 VBR-nrt nrtPS
Business Critical Out of Contract 8 1 1
Residential HSI
BE 0 0 0 0 UBR Best Effort
Business Best Effort
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 50
- 51. Example
Traffic Classes in an IPTV Network
Class EXP % Application
Bandwidth
Control 6 2 Routing Protocols, BGP, LDP
Real Time 5 25 LLQ for Voice over IP
IPTV Video 4 (Broadcast) 40 Delay sensitive business
3 (VoD) application, video conferencing
Business 2 (in-profile) 20 Telnet, SAP access, Email
1 (out-profile)
Best Effort 0 13 Internet Access
X
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 51
- 52. Example
QoS Classes to Queue Mapping
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 52
- 53. Example
IPTV QoS Design
Traffic Cos/ DSCP 6500/7600 GSR/
Class Prec 1p3q 1p3q 1p3q 1p3q8t/ 7600
1p7q8t OSM
SP Control 6 48 P (Q4) P (Q4) P (Q1) P/Q7T1 CBWFQ
Realtime/ 5 40 P (Q4) P (Q4) P (Q1) P LLQ
Voice
IPTV – 4 32 Q3 Q3 Q4T2 Q3T2/Q3T2 CBWFQ
Broadcast
Video
IPTV - VoD 3 24 Q3 Q3 Q4T1 Q3T1 /Q3T1 CBWFQ
Business 2 16 Q2 Q2 Q3T2 Q2T2/Q2T2 CBWFQ
In-contract
Business 1 8 Q2 Q2 Q3T1 Q2T1/Q2T1 CBWFQ
Out-of-contract
Best effort/ 0 0 Q1 Q1 Q2T2 Q1T1/Q1T1 CBWFQ
Internet
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 53
- 54. Resiliency High-
Availability
Video-to-Network layer
Linkages
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 54
- 55. Resiliency/High Availability (HA)
Device/component level
Dual RP (Non-Stop Forwarding/SSO)
Multiple links (Load-balancing across multiple links)
“Fix” Single point of failure conditions (edge card, router, link, source etc)
Multicast convergence
Unicast Convergence
Multicast Fast Convergence
Multicast Source redundancy
Anycast
Prioritycast
Path redundancy (using duplicate streams)
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 55
- 56. Multicast Convergence Elements
Convergence time T = T1+T2+T3+T4+T5
MCvg = T∆t + U∆t + N(RPF∆t + JP∆t)
MCvg = Multicast Convergence Time
T∆t = Topology Change Detection Time
U∆t = Unicast Convergence Time
N = Number of Multicast State Entries
RPF∆t = Reverse Path Forward Application Time
JP∆t = Join/Prune Message Processing Time
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 56
- 57. Elements of Convergence..
Fast Failure detection
Loss-of-signal (LOS) - SONET/POS, GigE LOS alarms
Bidirectional Forwarding Detection (BFD) - IETF
Protocol-independent method to detect control/data-
plane “liveliness” between two peer systems using hello-
like mechanism
Provides sub-second failure detection
Unicast Routing Protocol Convergence
Non-stop Forwarding (NSF), Graceful Restart
IGP Fast Convergence
Tuning of IGP timers (LSA gen, Throttling,
backoff etc) 100%
Incremental SPF (iSPF) 80%
IP Event Dampening 60%
Enable higher priority (route-tagging) for Video
40%
Headend Prefixes
BGP convergence optimization 20%
0%
BGP Update Packing, PMTU discovery etc
Before BGP With BGP
Convergence Convergence
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Optimization Optimization
57
- 58. …Elements of Convergence
Multicast Sub-second convergence
Set of IOS CLI for the following
Millisecond timers for PIM hello messages
Rapid, triggered RPF interface calculations
Improved IGMP and PIM state maintenance
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 58
- 59. Redundancy models
Dual streams (1+1 streams)
Let the receiver decide which one to take
More applicable in cable vs. DSL/FTTH
Heartbeat
Active sends periodic hello to standby (muted) source
Anycast Source
Two (or more) sources actively sending with same origin IP address
Network decides which one to use using its metrics
Disaster-recovery and redundant headend applications
IGMPv3 or IGMPv2
Receiver driven
Same group with two sources. STB decides which one to join using IGMPv3
Requires IGMPv3 support on STB
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 59
- 60. Source Redundancy (Duplicate Streams)
S1,G S2,G
STB I’m responsible
for dropping
duplicate packets
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 60
- 61. Source Redundancy (Server Heartbeat)
S1,G S2,G
STB I will only receive
one stream at
a time
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 61
- 62. Source Redundancy (Server Heartbeat)
X
S1,G S2,G
STB I will only receive
one stream at
a time
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential 62