architectures and technologies for optimizing sp video networks
DESCRIPTION
Architectures and Technologies for Optimizing SP Video NetworksTRANSCRIPT
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 1
Architectures and Technologies for Optimizing SP Video networks
Rajesh Rajah Consulting Engineer Cisco Systems
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 3
How do you get your TV today ?
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 4
What is IPTV?
Broadband IP Access Network
Today: xDSL, Cable Modem, FTTx, Carrier Ethernet, Future?: 3G, WiMax, ...
Subscriber IP-STB (Set Top Box)
Analog or Digital TV (increasingly HDTV)
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)
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 5
IPTV Architecture – View from space
“Glass to glass” experience
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 6
Delivery Networks with IP as Underlying Transport
Super HeadEnd (SHE)
Receive, Encode Mux, Encapsulate
WAN
IPmc
National Content
Local Access
Regional HE/VHO
Content Servers
Local/Regional Content
Content Servers/Portal
Rcv, Enc Mux,Encap, Stream
WAN
Regional HE/VHO
CORE
DISTRIBUTION AGGREGATION ACCESS CORE
MSO-Hub
ILEC-VSO
DISTRIBUTION
HFC NET
Mux EQAM
DSLAM
VQE AGGREGATION
Radio Tower
DVB-H
HSDPA
Local/Regional Content
Content Servers/Portal
Rcv, Enc Mux,Encap,Stream
WAN EVDO
WiMax
Satellite
Local Access
Mobile
Wireline
Cable
Local Access
Local Access XM-, L-, S-, K-Band…
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 7
MPEG/UDP/IP MPEG/RTP/UDP/IP
Analog or Digital
Encrypted MPEG
Demodulate and demultiplex TV signals. Local channels include PEG (Public, Educational, Government) channels.
To IP network as unicast streams.
Encrypted MPEG
Analog or Digital
Ad Splicer will take in the multicast stream and insert new ad content and output two streams with the same Multicast address, but different source addresses.
Local Affiliate
Middleware is the ‘brain’ of an IPTV network. It includes: - Electronic Program Guide - Entitlement System - Asset Distribution - Navigation Server It communicates with all set top boxes
Used by both broadcast and VoD
VoD Servers store video assets. The Middleware with the Entitlement system, Session Manager On demand manager, Policy Server for CAC, and video pump enable the streaming of programs.
Compress and encode one channel programming in MPEG-2 or 4; SD, HD and/or PiP. Output is IP multicast stream.
To IP network as multicast stream.
Encrypted MPEG
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 8
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
Next Generation Video Service Trends Driving network and in-home architectures…
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 9
IPTV – 2nd Wave On-net only TV Higher service velocity Business Model: B2C
Evolution to IP Video Unified experience and enhanced monetization
Traditional Cable – 1st Wave On-net only TV Limited service velocity Business Model: B2C
IP Video – 3rd Wave On-net or Off-net TV, PC, mobile Highest service velocity Business Model: B2B2C
More Open, More Flexible, More Monetization Opportunities
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 10
3rd Wave Drives Infrastructure Requirements
Requirement Internet Content (Hulu, Netflix)
Personal Media (YouTube)
3rd Wave Video (including Time-Shift TV)
Services Live, VoD, Interactive, Social VoD, Interactive, Social Live, Time-shift, VoD,
Interactive, CDN Ready
Usage / Devices M Copies : N Subs PC, some mobile
1 Copy : N Subs PC, some mobile
1 Copy : N Subs STB, PC, Mobile
Ingest Feeds Scale / Performance
10s, Non real-time
1,000s, Non real-time
100s, Real-time and Non real time
Storage Scale / Resiliency
10-20K Titles, 10s of Terabytes, Med Resiliency
100M+ Titles Petabytes,
Low Resiliency
100K Titles 100s of Terabytes 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)
File Formats / Protocols HTTP, MS, Adobe Adaptive Emerging HTTP, MS, Adobe MPEG, H.264, Internet Content
Ready
File Sizes, Caching Benefits
Small to Med, High Caching
Small, Low Caching
Large, High Caching
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 11
CPE / So(ware / UI / Apps
• Home Gateway • STBs • PCs • Game Consoles • Mobile Phones
Content Ingest and Transport Edge Network
• IP Edge, QAM and HFC • FTTH • xDSL • On-‐Net and Off-‐Net
Content Delivery Network
• Library Server • Caching Gateway • Internet Streamer
Encoding
• H.264 Encoding • MP4 Wrapping
Video Datacenter
Security
• DRM • License Servers • Security OperaVons
Backoffice
• Billing • EnVtlement
ApplicaVon Servers
• RUI HosVng • ApplicaVon Services
Service PlaXorm
• Session and Resource Management • Metadata • Content Management • AdverVsing
Linear /SDV
• Splicing • Grooming
Unified CompuVng PlaXorm
IP Video Solution – 3rd Wave High Level Functional Areas
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 12
CPE / So(ware / UI / Apps Content Ingest and Transport Edge Network (IP Edge, QAM and HFC)
Content Delivery Network
Content Library
Cache Nodes
Internet Streamer
STB/PC with player
Internet
CDN CCPH C2
Off-‐Net OpVon
Video Management
HFC
Encoding
H.264 Encoder and MP4 wrapping
Video Datacenter
Security / DRM Backoffice / Billing
BSS/ EnVtlement/
IdenVty
ApplicaVon Servers
Discovery: Navigation
and Selection
Service PlaXorm
ApplicaVon Router
Policy Server
Service Router
Ad Decision System
PATH SRM
DRM
PC with player
Home Network
IPSTB with player
Home Gateway
Mobile Phone
Linear /SDV
Splicer/ Groomer
File-‐based OnDemand Assets and Linear Programs
Unified CompuVng PlaXorm
Game Console
IP Video Solution - 3rd Wave Functional Blocks, Components, and Flows
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 13
Connected Home IP Network
News Gathering
Primary Distribution
Secondary Distribution Production
Sport Events
Studio-to-Studio
Video Data Center
IP Network
Post Production
MWP
Direct to Home Headend
Broadband CDN
IP IP
Core Network
Home Gateway
Headend Telco
IP
Cable
IP
Headend
Over the Air
IP
Headend
IP
Broadcast Media Content Delivery Architecture Key Building Blocks
Post Production & Playout Consumption Transport Content Adquisition
& Signal Processing
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 14
Video Service Providers: Taxonomy & Characteristics
Uncompressed, Lossless
Very High bit-rate stream: SD (270Mbps), HD (1.5-3Gbps)
P2P and P2MP (unicast and multicast)
P2MP MPLS focused
e.g. BT M&B, RAI
Compressed
Low/moderate bit-rate streams ~ same as or similar to secondary dist
P2P and P2MP (unicast and multicast)
MPLS & IP technology
e.g. Contribution providers, US national backbones
Compressed
Low bit-rate streams: SD (3-4Mbps MPEG2, 2-3Mbps MPEG4), HD (16-20Mbps MPEG2, 6-10Mbps
MPEG4)
P2P for VOD (unicast) & P2MP for IPTV & CATV (multicast)
MPLS & IP technology
e.g. DT, FT, Comcast, …
Stadium Studio
Mobile Studio Fixed
Studio
Final Studio
IP/MPLS Core
IP/MPLS Core
IP/MPLS Core
Home Network
Access and Aggregation
Super Head End (×2)
DCM
National Content Insertion
CDS CDS VOD content distributing to scale
DCM
Head End (×2)
Local Content Insertion
VQE
VSOs (×100s)
Homes × millions
Higher bw streams More end points
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 15
Video Transport Services in the SP Video Ecosystem
Consumption
Headend News Gathering
Primary Secondary Distribution Contribution Production
Ingest
Sport Events
Video Data Center
Post Production
Core IP Network
IP
IP
IP IP
Headend
Headend
Direct To Home
Telco
Cable
Mobile
Studio to Studio
Contribution Service
Studio to Studio Uncompressed
Very High bit-rate Unicast and Multicast
Primay Distribution Service
Content origination to Provider Compressed Low to high
Unicast and Multicast
Secondary Distribution Service
Provider to Consumer Compressed
Low to Moderate bit-rate Unicast and Multicast
Increase number of end points
Increase Bandwidth and SLA Requirements
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 16
Access Independence
One headend, one IP network Multiple access networks, Multiple screens
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 17
Video-to-Network layer Linkages
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 18
Unicast, Multicast Performance
and Scalability
Video Service Assurance (QoS, QoE
monitoring etc)
Admission Control Video Service
Bandwidth Management
Visual Quality of Experience (VQE)
Error Repair, RCC
Video Service & Network
Resiliency against failures, DoS attacks
IP Video / IPTV Solution Network to Video layer Linkages
Network Layer
Video Application Layer
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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 of the viewer
General definition for QoE: Impairments/time Mean Time Between the Artefacts
Common industry benchmark 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
Slice error
Pixelisation
Ghosting
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 21
What is the most efficient way to control loss? Cost / Complexity Tradeoff
Causes of packet loss: Excess Delay
Prevent with QoS (i.e., Diffserv)
Congestion Prevented with Capacity planning, QoS and CAC
PHY-Layer Errors (in the Core) Insignificant compared to losses due to network failures
Network Reconvergence Reduce with high availability (HA) techniques and smart engineering
Number of possible approaches, or combinations of approaches.
Loss (Impairments/Time)
Cos
t an
d C
ompl
exity
Re-engineering Required
Pote
ntia
l Ove
r-
Engi
neer
ing Viable-
Engineering
Range of viable engineering options may vary by type of video distribution, service or content
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 22
Services Comparison and Requirements Services/ Attributes Broadcast Video Video-on-Demand
(VoD) Internet Data
Transport Multicast Unicast Unicast
Service Separation
Common Video VLAN termination on the U-PE.
IGMP/PIM-based multicast control flow
Common Video VLAN termination on the U-PE. L3 routing between VoD
server and U-PE
VLAN-per-DSLAM for Internet subscriber. L2
Point-to-point Pseudowire from U-PE
to BRAS
Convergence OSPF FC, BFD, Multicast
FC, MPLS TE FRR (Routed PW)
OSPF FC, BFD, MPLS TE FRR OSPF FC, BFD, MPLS
TE FRR
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
Admission control
IGMP state limits Off-path, RSVP-based
On-path CAC, or Integrated CAC
BRAS
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 23
Services Comparison and Requirements - continued
Services/Attributes Broadcast Video Video-on-Demand
(VoD) Internet Data
QoS Priority Separate Video Queue with
Higher priority than VoD
Separate Video Queue with Higher priority than
VoD Best effort
Acceptable Packet drop rate
10-6 (one artifact per 2-hr movie)
10-6 (one artifact per 2-hr movie) NA
Latency (RTT) requirements
<200ms <200ms NA
Jitter requirements
<50ms <50ms NA
QoS WRED No No Yes
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 24
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
Video/IPTV Optimized Transport System Primary challenges
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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
– Native (PIM SSM)
– mVPN
– LSM (Label Switched Multicast)
– P2MP TE global
– PW over P2MP TE
– mLDP
• mLDP global
• mLDP + mVPN
IP
MPLS (LSM)
Multicast
mVPN MLDP
P2MP TE
mVPN
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 26
Video Contribution Secondary Distribution
Managed Enterprise mVPN
PIM mode SSM only SSM only SM and SSM Sources per multicast group
1 or 2 1 or 2 1 or 2
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; trees static once
established
Static trees Trees are dynamic; joins and leaves may impact core
Admission control and Bandwidth Reservation
Yes (time limited reservations)
No No
Fast ReRoute Yes Yes Yes Offload routing Yes No No Path diversity Yes Yes Yes mVPN requirement ? For wholesale
services Yes
p2mp or mp2mp? p2mp p2mp mp2mp
26
Requirements Comparisons for Multicast Based Services running on a Converged IP network
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 27 © 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential C25-452149-02
Characteristic Plain IP Multicast
p2mp MPLS TE mLDP
Convergence < ~500ms ~50ms < ~1s Offload routing
IGP metric based traffic engineering
IGP metric based traffic engineering
Path separation
MoFRR or MTR
MoFRR or MTR
Admission control and bw reservation
RSVP
Scalable mp2mp MVPN
Mapping of Multicast Service Requirements to p2mp technology choices
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 28
PIM Source Specific Mode (SSM)
Result: Shortest path tree rooted at the source, with no shared tree.
Middleware
STB
B A C D
F E
Encoder
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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)
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 30
Access Aggregation
End-to-end protocol view – Layer3 Agg
STB Home Gateway
Eg: DSLAM PE-AGG
Core Distribution / regional
Home Network Video Headend
Same choices for all access technologies Different by access technology
PIM-SSM (S,G) joins IGMP membership
IGMP Proxy
IGMP snooping
IGMP: {Limits} {Static-fwd} PIM-SSM PIM-SSM
L3 Transport Options in clouds: Native: PIM-SSM or MVPN/SSM MPLS: LSM / mLDP RSVP-TE Opt.
Source Redundancy
IGMP
PIM-SSM
Video Stream
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 31
Access Aggregation
End-to-end protocol view digital (non DOCSIS) cable
Cable STB HFC PE-AGG
Core Distribution / regional
Home Network Video Headend
Same choices for all access technologies Different by access technology
PIM-SSM (S,G) joins IGMP membership
IGMP snooping
IGMP: {Limits} {Static-fwd} PIM-SSM PIM-SSM
L3 Transport Options in clouds: Native: PIM-SSM or MVPN/SSM MPLS: LSM / mLDP RSVP-TE Opt.
Source Redundancy PIM-SSM
Video Stream
eQAM HFC
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 32
Access Aggregation
End-to-end protocol view – Layer2 Agg
STB Home Gateway
Eg: DSLAM PE-AGG
Core Distribution / regional
Home Network Video Headend
Same choices for all access technologies Different by access technology
PIM-SSM (S,G) joins IGMP membership
IGMP Proxy
IGMP snooping
IGMP: {Limits} {Static-fwd} PIM-SSM
L3 Transport Options in clouds: Native: PIM-SSM or MVPN/SSM MPLS: LSM / mLDP RSVP-TE Opt.
Source Redundancy
IGMP
PIM-SSM
Video Stream
L2 access
IGMP snooping
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 33
Network Resiliency
Video-to-Network layer Linkages
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 34
Fast Convergence - reduces affect of link outage (~ 500ms)
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
Core Distribution (DCM)
Edge Distribution (DCM or VQE)
Primary Stream
Rerouted Primary���Stream
Video Source
Video Receivers
X
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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
MoFRR depends on natural spatial diversity of large networks, disjointed physical topology with dual edge to dual core
Can be used for both loss and lossless approaches and be implemented in the network or on the video end system
= Receiver
= IGMP Join
= PIM Join
= Source
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 36
Mapping of Multicast Service Requirements to p2mp technology choices
36 © 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential C25-452149-02
Characteristic Plain IP Multicast
p2mp MPLS TE mLDP
Convergence < ~1s ~50ms < ~1s Offload routing
IGP metric based traffic engineering
IGP metric based traffic engineering
Path separation
MoFRR or MTR
MoFRR or MTR
Admission control and bw reservation
RSVP
Scalable mp2mp MVPN
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 37
Towards Lossless Video/IPTV Transport: Deployment Scenarios
MPLS TE FRR + FEC or TR
MTR + Live / Live
Fast Convergence +
FEC or TR
MoFRR + Live / Live
Fast Convergence
MPLS TE FRR
MoFRR
TE + Live / Live
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 38
Towards Lossless Video/IPTV Transport: Deployment Scenarios
MTR + Live / Live
MoFRR + Live / Live
Fast Convergence
MPLS TE FRR
MoFRR
TE + Live / Live
Recommended approach where some loss is tolerable and topology does not support MoFRR • Lowest bandwidth
used in working and failure cases
• Lowest solution cost and complexity
• Constrained impact of network failures on video
Recommended approach where some loss is tolerable and topology supports MoFRR • Lowest bandwidth
used in working and failure cases
• Lowest solution cost and complexity
• Constrained impact of network failures on video
MPLS TE FRR + FEC or TR
Fast Convergence +
FEC or TR
Recommended where lossless approach is required and topology supports path diversity with MoFRR • Lowest bandwidth
used in failure cases • Low solution cost
and complexity • Does not apply to
all topologies
Options where a lossless solution is required and the topology does not support path diversity with MoFRR
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 39
IPv4 and IPv6 Multicast Comparison Service IPv4 Solution IPv6 Solution
Addressing Range 32-bit, Class D 128-bit (112-bit Group)
Routing Protocol Independent, All IGPs and MBGP
Protocol Independent, All IGPs and MBGP with v6
mcast SAFI
Forwarding PIM-DM, PIM-SM, PIM-SSM, PIM-bidir
PIM-SM, PIM-SSM, PIM-bidir
Group Management IGMPv1, v2, v3 MLDv1, v2
Domain Control Boundary, Border Scope Identifier
Interdomain Solutions MSDP across
Independent PIM Domains
Single RP within Globally Shared Domains
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 40
Multicast Feature Recommendations Features / Platform Core
(N-PE/PE) Aggregation
(PE-AGG if L2 U-PE)
Aggregation (PE-AGG if L3 U-
PE) Access
(Layer3 U-PE)
Access (Layer2 U-
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
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 41
Multicast Feature Recommendations
Features / Platform VHE (7600)
DSLAM Residential Gateway (RG)
STB
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
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 42
Quality of Service
Video-to-Network layer Linkages
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 43
U-PE
Internet
GE Ring
SONET/SDH Ring
Access Access Core Edge Edge Aggregation
Hub & Spoke
Hub & Spoke
Enterprise A
Enterprise B
Enterprise B
10/100/ 1000 Mpbs
Enterprise A
10/100/ 1000 Mpbs
10/100/ 1000 Mpbs
U-PE
U-PE
U-PE
N-PE
N-PE
N-PE
PE-AGG P
P P
10/100/ 1000 Mpbs
CE CE
• Classification • Policing • Marking • Egress Queuing
Access
• Egress Queuing
Aggregation
• Marking • Traffic Shaping
CE
• Egress Queuing
Edge
• Egress Queuing • Congestion Avoidance
N-PE
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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.
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 46
Video optimised Diffserv Schedulers
Cisco leads the industry in the development and support of multi-priority schedulers implementations
Enables differentiation between premium services, requiring bounded delays
B
R
Policer
RED
Scheduler
Bandwidth queue
Strict priority queue
Bandwidth queue
Bandwidth queue
Classifier Per-class policy
RED
Tail Drop
B
R
Policer Classifier
EF #1
Tail Drop
AF #1
EF #2
AF #n
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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.
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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.
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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.
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 50
Traffic Class Core /Edge/ Aggregation Access UNI
MPLS/IP Ethernet DSL, ETTX DSL WiMAX
PHB DSCP MPLS EXP 802.1P 802.1P ATM 802.16
Control Protocols Network Management
AF 48 6 (6) (6) VBR-nrt nrtPS
Residential Voice Business Real-time
EF 46 5 5 5 VBR-rt rtPS
Residential TV and VoD AF 32 4 4 and 3 4 VBR-nrt
NA
Business Critical In Contract Business Critical Out of Contract
AF 16 8
2 1
2 and 1 2 1
VBR-nrt nrtPS
Residential HSI Business Best Effort
BE 0 0 0 0 UBR Best Effort
IPTV DiffServ QOS Domain Example
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 51
Class EXP % Bandwidth
Application
Traffic Classes in an IPTV Network
5
Control
Real Time
Business 2 (in-profile) 1 (out-profile)
20
X
IPTV Video 40 4 (Broadcast) 3 (VoD)
Best Effort 13 0
6
25
2 Routing Protocols, BGP, LDP
LLQ for Voice over IP
Delay sensitive business application, video conferencing
Telnet, SAP access, Email
Internet Access
Example
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 52
QoS Classes to Queue Mapping Example
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 53
IPTV QoS Design Traffic Class
Cos/ Prec
DSCP 1p3q 1p3q 1p3q
6500/7600 1p3q8t/1p7q8t
GSR/ 7600 OSM
SP Control 6 48 P (Q4) P (Q4) P (Q1) P/Q7T1 CBWFQ
Realtime/ Voice
5 40 P (Q4) P (Q4) P (Q1) P LLQ
IPTV – Broadcast
Video
4 32 Q3 Q3 Q4T2 Q3T2/Q3T2 CBWFQ
IPTV - VoD 3 24 Q3 Q3 Q4T1 Q3T1 /Q3T1 CBWFQ
Business In-contract
2 16 Q2 Q2 Q3T2 Q2T2/Q2T2 CBWFQ
Business Out-of-contract
1 8 Q2 Q2 Q3T1 Q2T1/Q2T1 CBWFQ
Best effort/ Internet
0 0 Q1 Q1 Q2T2 Q1T1/Q1T1 CBWFQ
Example
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 54
Resiliency & High-Availability
Video-to-Network layer Linkages
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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)
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 56
Multicast Convergence Elements
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
Convergence time T = T1+T2+T3+T4+T5
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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) Incremental SPF (iSPF) IP Event Dampening Enable higher priority (route-tagging) for Video Headend Prefixes
BGP convergence optimization BGP Update Packing, PMTU discovery etc
Before BGP Convergence Optimization
With BGP Convergence Optimization
0%
20%
40%
60%
80%
100%
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 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
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 60
Source Redundancy (Duplicate Streams)
S1,G S2,G
I’m responsible for dropping duplicate packets
STB
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 61
Source Redundancy (Server Heartbeat)
S1,G S2,G
I will only receive one stream at a time
STB
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 62
Source Redundancy (Server Heartbeat)
S1,G S2,G
I will only receive one stream at a time
X
STB
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 63
Regional Backbone
Regional Backbone
Service Edge National Backbone Source Residence Regional Backbone
Regional Backbone
Primary Source 1
P
P
Secondary Source 1
Hea
rtbea
t
Primary Source 2
Secondary Source 2
Hea
rtbea
t
Primary Source 3
Secondary Source 3
Hea
rtbea
t
PE
PE
PE P
P
P
P
P
P
PE
PE
X
PE
PE
Native IP Multicast Video Triple Play Redundancy : Video Source Failure
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 64
Source Redundancy (SSM)
S1,G IGMPv3 Report
S1,G Join
S1,G S2,G
I’ll try the Primary source, S1,G.
STB
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 65
Source Redundancy (SSM)
S1,G S2,G
S2,G Join
S2,G IGMPv3 Report
It appears the Primary source failed. I’ll switch to the Secondary source, S2,G.
STB
X
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 66
Anycast Sources
1.1.1.1 1.1.1.1
IGMP Report
v2 join
I will send join to the nearest 1.1.1.1/32
IGMP Report
I will send join to the nearest 1.1.1.1/32
v2 join
STB STB
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 67
Anycast Sources
1.1.1.1 1.1.1.1
I will send join to the nearest 1.1.1.1/32
v2 join
STB STB
X
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 68
Source Redundancy Anycast/Prioritycast policies
Policies
Anycast: clients connect to the closest instance of redundant IP address
Prioritycast: clients connect to the highest-priority instance of the redundant IP address
Policy simply determined by routing announcement and routing config
Anycast well understood
Prioritycast: engineer metrics of announcements or use different prefix length.
No vendor proprietary source sync proto required
Per program, not only per-source-device failover Use different source address per program
Src B secondary
10.2.3.4/32
Rcvr 2 Rcvr 1
Src A primary
10.2.3.4/31
Example: prioritycast with Prefixlength announcement
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 69
Source Redundancy Anycast/Prioritycast benefits
Sub-second failover possible Represent program channel as single (S,G)
SSM: single tree, no signaling, ASM: no RPT/SPT
Move instances “freely” around the network Most simply within IGP area Not good for eg: regional to national encoder failover
No vendor proprietary source sync proto required Per program, not only per-source-device failover
Use different source address per program
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 70
Anycast-Source with RIPv2 Update
s s/32, m=1
1
redistribute s/32, metric 10
• The two sources are active and sending • s/32 routes are generated by both source using RIPv2 updates • Host routes for anycast source are redistributed into IGP with variable metrics
(optional) • Network selects source (PIM join messages) based on metric • Upon video failure, sources withdraw s/32 routes using Poison Reverse
(infinite metric) updates
ENC ADP
s s/32, m=1
2 ENC ADP
redistribute s/32, metric 5 s
s/32, m=16 1
ENC ADP
s s/32, m=1
2 ENC ADP
X
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 71
Regional Backbone
Regional Backbone
Service Edge National Backbone Source Residence Regional Backbone
Regional Backbone
Primary Source 1
P
P
Secondary Source 1
Hea
rtbea
t
Primary Source 2
Secondary Source 2
Hea
rtbea
t
Primary Source 3
Secondary Source 3
Hea
rtbea
t
PE
PE P
P
P
P PE
P
PE
PE X P
PE
PE
Native IP Multicast Video Triple Play Redundancy : Source Router Failure
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 72
Multicast Group Based : Multi-path Load Splitting
Active Video Server
Standby Video Server
Hea
rtbea
t
R1
R3 (S,G1) (S,G2) (S,G3) (S,G4)
BEFORE
Active Video Server
Standby Video Server
Hea
rtbea
t (S,G1) (S,G2) (S,G3) (S,G4)
Now
Source + Group Based Load Splitting
All Links Efficiently Used!
R1
R3
R4
R5
R2
(S,G1)
(S,G2)
(S,G3)
(S,G4)
(S,G1)
(S,G2)
(S,G3)
(S,G4)
Source Based Load Splitting
Links Unused R4
R5
R2
Hash based on Source Requires unique sources for load splitting
Hash based on S,G
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 73
Multicast HA & Convergence High Availability
HA/Convergence features Broadcast Video Traffic Video-on-Demand traffic
Redundant RP, Power supply, Fan tray, Fabric cards
OSPF Fast Convergence
OSPF iSPF
Bidirectional Forwarding (BFD)
P2P MPLS Traffic Engineering (MPLS TE)
Not Applicable
Multicast sub-second convergence
Not Applicable
L2 Pseudowire
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 74
Security
Video-to-Network layer Linkages
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 75
Multicast Security.. Protect router/switch CPU (control plane)
Control Plane Policing (CPP) – Policing on router-wide virtual control plane
Hardware Rate-limiters (HRWL mls ratelimiters)
MQC-based (per-interface)
Enable multicast protocol filtering/setting administrative boundary
Boundary ACL (Filters control/data plane traffic for specified groups using “ip multicast boundary” CLI)
Receive ACL
Enable spoof prevention MD5 authentication, PIM Neighbor filters
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 76
.. Multicast Security
Prevent Memory (SW) and Hardware (state) overload IGMP, MLD limits /max-groups IP Multicast Route limits (ip multicast limit CLI)
Allow traffic only from STBs to Video Servers (data-plane filtering)
Generic ACLs (typically on user-facing intefaces/SVIs) Restrict access to Channels based on User subscription
Offer Tier-based services (Premium, Gold, Silver packages etc) at Network level
Use of IGMP Profile/access-group CLI on a per-interface basis Network Address Translation (NAT)
Source address NAT Destination/Multicast Group NAT (aka Service Reflection) Useful when Overlapping address space is present, Integrating existing/new networks, etc
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 77
Multicast Admission control IGMP/MLD Limit Commands
Malicious IGMP/MLD Reports
Valid Periodic IGMP/MLD Reports
0
max
time
Tota
l M
emor
y U
tiliz
atio
n
t1 t2
time = t1 time = t2
Gasp!
0
unlimited
time
IGM
P/M
LD
Ent
ries
t1 t2 tn tn
Other Processes
IGMP/MLD Table
Memory Resources
What does it do ? • Sets quota on the number of cached
entries in IGMP/MLD tables • Channel Offering Limits in household
• Denial of Service has been mitigated!
How it works: • Time = t1, router receives valid
IGMP/MLD Join(s), populates table(s) and allocates required memory
• Time = t2, router suddenly receives malicious IGMP/MLD Join(s) and table(s) quickly begins to grow
• Time = tn, all memory resources are exhausted and router is unable to service other processes requesting more memory
• Now, user sets IGMP/MLD limit
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 78
Ethernet Access Security Threats
Subscribers Switches Infrastructure Layer 2 service isolation across switches
L2 Control Protocol Attack (STP, CDP, VTP, etc…)
Man-in-the-Middle attacks on critical management traffic
Non intentional forwarding of traffic between UNI ports
MAC Flooding / Overflow Unauthenticated access to the switch configuration file
DHCP Rogue Server MAC Flooding / Overflow Unconfigured Ports providing network access
IP & MAC Address Spoofing Unicast, multicast, or broadcast storms
Unauthorized network access, junk traffic
ARP Spoofing (Man-in-the-Middle)
Infected users flooding the network / Malicious users attacking the Priority traffic queue
Unauthenticated network access by client devices
Attack targets can be divided into three main categories:
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 79
Common Security Recommendations How to Secure the Network Against Attacks
Leading Practice Category Examples Protects Against Threats
Disable Unnecessary Services ICMP redirects, CDP, IP Source Routing Reconnaissance, Denial-of-Service
Control Device Access TACACS+, Radius, Password Encryption Unauthorized Access
Secure Ports and Interfaces Disable unused interfaces, VLAN Pruning Reconnaissance, Denial-of-Service
Secure Routing Infrastructure MD5 Authentication, Route Filters Denial-of-Service
Secure Switching Infrastructure Port Security, Storm Control Denial-of-Service
Control Resource Exhaustion Control Plane Policing (CoPP), Hardware-based Rate Limiters Denial-of-Service
Policy Enforcement uRPF, iACLs IP Spoofing, Denial-of-Service
DSLAM MAC Forced Forwarding, Virtual MACs, DHCP Option 82, IGMP
Whitelist
Reconnaissance, MAC Spoofing, Theft-of-Service
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 80
Residential Access Leading Practices How to Secure Users and Services
Goal Features
Subscriber Identification DHCP Option 60, DHCP Option 82
Subscriber Authentication PPPoE or Web Portal (Using Radius)
Subscriber Isolation MAC Forced Forwarding on DSLAM
Private VLAN/PVLAN Edge on Switch
Rogue DHCP Server DHCP Snooping
Prevent MAC/ARP Address Spoofing Virtual MAC Addresses on DSLAM
DHCP Snooping + ARP Inspection on Switch
Prevent Theft of BTV Service IGMP Whitelist on DSLAM
IGMP Profile/Access-group on Switch
IP address spoofing DHCP Snooping + IP Source Guard (IPSG) on Switch
Limiting No. of Channels/IGMP/Multicast states
IGMP State limits/max-groups & Multicast limits on Switch
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 81
Layer 2 Leading Practices
Attack Defensive Features/Actions
MAC Attacks (CAM Table Overflow) Port Security, Per VLAN MAC Limiting
Broadcast/Multicast Storm Attacks Storm Control Thresholds
L2PDU DoS Attacks Hardware Rate Limiters, Control Plane Policing, Storm Control Thresholds
VLAN Hopping, DTP Attacks
Disable Auto-trunking, Use Dedicated VLAN-ID for Trunk Ports, Set User Ports to Non-trunking, VLAN 1 Minimization/Pruning, Disable Unused
Ports
DHCP Starvation Attack DHCP Rogue Server Attack
Port Security, DHCP Snooping, VLAN ACLs to block UDP port 68
Spanning Tree Attacks BPDU Guard, Root Guard
Infected users flooding the network / Malicious users attacking the Priority traffic queue
Rate-limiting, Priority policing
ARP Man-in-the-Middle Dynamic ARP Inspection
How to Secure the Network Against Layer 2 Attacks
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 82
Infrastructure Security Leading Practices
Security Threats
Man-in-the-Middle attacks on critical management traffic
Unauthenticated access to the switch configuration
Unauthenticated network access by client devices
Unconfigured Ports providing network access
Unauthorized network access, junk traffic
Out-of-Band Management, SNMPv3, SSH, per-command AAA
Password recovery disable
802.1x
UNI Default Port Down
Access Lists
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 83
Visual Quality of Experience
Video-to-Network layer Linkages
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 84
Without VQE VQE Enabled
Noisy Last Mile
Improving Cisco IPTV Experience Non-Stop Visual Quality Experience (VQE) Technology
VQE Server
Aggregation Router
Access Node Access Node
• Caches all Video channels • Retransmits lost packets to STB
Visual Quality
Experience (VQE)
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 85
Channel change Events Summary
STB MPEG
Network
STB Related to STB implementation
Related to network delays
Related to STB MPEG buffer Not to scale*
STB STB Network STB
User hits channel change on remote
SW starts channel change STB sends IGMP leave (wire), clear old buffers
STB sends IGMP join (wire)
Leave/Join/Network Latency
STB MPEG Buffer
1st UDP packet arrives at STB
SW recognizes UDP pkt
Start filling jitter buffer
Jitter buffer full Wait for arrival of PSI – PAT, PMT, CAT
Wait for arrival of I-frame
STB MPEG buffer processing complete
STB starts decode
Channel change complete
Video/Audio is played
* t=0
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 86
Sample Channel change time calculation AVC/H.264 SD on IPTV DSL
Channel Change Latency Factor Device/Location Typical
Latency Cumulative
Latency 1 Send IGMP Leave for channel X STB < 10 ms 2 Send IGMP Join for channel Y STB < 10 ms
3 DSLAM gets Leave for channel X DSLAM/Network < 10 ms
4 DSLAM gets Join for channel Y DSLAM/Network < 10 ms ~ 20 - 40 ms
5 DSLAM stops channel X, and sends Channel Y DSLAM/Network ~ 30 – 50 ms ~ 50 – 90 ms
6 DSL Latency (FEC/Interleave) DSLAM/Network ~ 10 ms ~ 60 - 100 ms 7 Core/Agg Network Latency Router/Network ~ 20 – 60ms ~80 – 160ms 8 De-jitter buffer STB ~ 300 ms ~ 380 - 460 ms 9 Wait for PAT/PMT STB MPEG buffer ~ 125 ms ~ 500 - 580 ms
10 Wait for ECM/CA STB MPEG buffer ~ 125 ms ~ 620 - 700 ms 11 Wait for I-frame STB MPEG buffer ~ 250 ms to 2s ~ 870 ms – 2.7s 12 MPEG buffer STB MPEG buffer ~ 1s to 2s ~ 1.8s – 4.7s
13 Decode STB ~ 50 ms ~ 1.9s – 4.8s
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 87
Optimizing Channel change time – Page 1
Device Optimization Factors
Encoder GOP length tuning Tuning PAT/PMT intervals (if supported)
Conditional Access Tuning of ECM intervals (PMT) Key rotation timeframe
Residential Gateway (RG)
Tuning IGMP timers Video-optimized QoS config#
STB Cache PAT/PMT Buffer optimization and play-out techniques
# Not a direct contributor to reduce zap time. But, helps reduce response variability and enables better treatment for Video
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 88
Optimizing Channel change time – Page 2
Device Optimization Factors
Headend Router Video-optimized QoS config #(marking, scheduling etc)
Core Network Elements Secured control plane #(PIM/IGMP limits, Control plane policing, Hardware rate-limiters etc) Video-optimized QoS config #
Distribution/Aggregation Network Elements
IGMP static joins for popular channels Video-optimized QoS config # Secured control plane #
Access Network Elements (DSLAM/MetroE switch/
PON)
IGMP Fast/Immediate leave Tuning IGMP timers (Query time etc) Explicit IGMP Host tracking (IGMPv3) Video-optimized QoS config # Secured control plane #
# Not a direct contributor to reduce zap time. But, helps reduce response variability and enables better treatment for Video
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 89
Visual Quality
Experience (VQE)
Cisco IPTV Fast Channel Change Combined VQE Unicast stream & Client Early Channel Change!
Combined Cisco Fast Channel Change: Average: ~0.7 sec Variance: ~0.4 sec
Un-optimized channel change time stats: Average: ~2.2 sec Variance: ~1.2 sec
Access Node
Set-Top Box
Early Channel Start & VQE I-frame burst
VQE Server +
+ Aggregation Router
• Caches all Video channels • Bursts Video streams to STB starting with I-frame
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 90
Admission Control
Video-to-Network layer Linkages
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 91
Media-aware IP NGN Video Call Admission Control (CAC)
Video Streams
2 VoD Streams—4Mbps Each
Video Quality Fantastic Video Quality Suffers (for ALL users)
3 VoD Streams—4Mbps Each
10 Mbps
4 Mbps
4 Mbps
VoD TV
10 Mbps
4 Mbps
4 Mbps
4 Mbps
Gracefully Rejects 3rd VoD Stream
10 Mbps
4 Mbps
4 Mbps
4 Mbps
3 VoD Streams—4Mbps Each with Video CAC
End-2-End Video CAC (RSVP-based)
7600 ASR9000
Video Admission
Control
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 92
VoD Request
Policy Server
Channel request
Request Denied/ Accepted
RSVP-CAC
Video on Demand Unicast CAC
VoD Servers
Available Bandwidth Check
Available Bandwidth Check
Network Call Admission Control Avoiding Congestion Packet Loss
Against a DiffServ prioritized percentage of link bandwidths
IPTV Channel Change
Broadcast Source
Policy Server
Channel request
Request Denied/ Accepted
1 4
2
Multicast CAC
Broadcast TV Multicast CAC
1 4
2
3
3 Available Bandwidth Check
Available Bandwidth Check
Cisco 7600
Cisco 7600
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 93
Carrier Ethernet Aggregation"
Core Network IP / MPLS
BNG
BNG
Edge"
DSL Access Node
Access"
Business
Corporate
Residential
STB
Residential
STB
Business
Corporate
Business
Corporate
Residential
STB
PON Access Node
Aggregation Network
IP
Distribution Node
Distribution Node
Aggregation Node
Aggregation Node
Multiservice Core"
Ethernet Access Node
Ethernet Access Node Aggregation
Node
Aggregation Node MSE
MSE
VoD Controller Entitlement Sys
Session Mgt, EPG
Middleware
RSVP Path 4
eg RTSP 3 1
2
VoD Stream
6
RSVP Resv
5 CAC CAC CAC
Pure On-Path CAC for VoD Synchronisation between RSVP and VoD streaming
Content Network
VoD TV SIP
VoD
VoD
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 94
Carrier Ethernet Aggregation"
Core Network IP / MPLS
BNG
BNG
Edge"
DSL Access Node
Access"
Business
Corporate
Residential
STB
Residential
STB
Business
Corporate
Business
Corporate
Residential
STB
PON Access Node
Aggregation Network
IP
Distribution Node
Distribution Node
Aggregation Node
Aggregation Node
Multiservice Core"
Ethernet Access Node
Ethernet Access Node Aggregation
Node
Aggregation Node MSE
MSE
VoD Controller Entitlement Sys
Session Mgt, EPG
Middleware
RSVP Path 4
eg RTSP 3 1
2
Pure On-Path CAC for VoD Synchronisation between RSVP and VoD streaming
Content Network
VoD TV SIP
VoD
VoD
RSVP Resv 5
CAC CAC Reject
RSVP PathErr
6
eg RTSP 7
See draft-ietf-tsvwg-rsvp-proxy-proto
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 95
Video Quality Monitoring/Assurance
Video-to-Network layer Linkages
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 96
Video/IPTV Quality Measurements (What Can Go Wrong)
Content Measures Picture Quality, Blocking, Blurring, Visual Noise, Audio Drop-outs
Media Transport Measures PCR Jitter, Pixelization, Sync Loss, Continuity Errors
IP Network Measures Packet Loss, Jitter, Delay
Physical
Visual
Ethernet
IP
UDP
RTP
MPEG-TS
Content
Cont
rol
Control Measures IGMP Latency, RTSP Latency, Channel Zap Time
Error Type
QoE Errors Impacts Customer
QoS Errors Impacts Operator
Control Plane Problem
Video Problem
IP Problem
Problem Area
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 97
VidMon is a Family of Metrics
VidMon does not represent a single metric but rather a family of Metrics.
Not all Routers have the same capabilities and therefore Metrics will vary across platforms.
The applicability of a VidMon Metric will differ based on the type of Video being Monitored
VidMon Metrics can be used independently or used to compliment each other.
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 98
The VidMon Metrics
Transport IP UDP RTP FCS UDP Video Payload Content
(MPEG is not the only payload option)
Example Video Packet in over an IP Transport
Metric Applicability
Media Delivery Index (MDI) Measures MPEG2/4 Headers for Loss and Delay
Media Discontinuity Counter (MDC) Measures MPEG2/4 Headers for the number of times Loss was detected.
Media Rate Variation (MRV) Measures IP/UDP Headers for Delivery Variations.
RTP Loss and Jitter Measures RTP Loss and Delay by examining the RTP header
Media Stop Event (MSE) Notification if a monitored flow stops receiving traffic
MPEG Header
MPEG Payload
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 99
What is Media Delivery Index (MDI)
MDI is a metric developed in cooperation between IneoQuest and Cisco
Presented in RFC-4445
MDI is a combination of two metrics that are used to measure the networks contribution to video impairements.
The two MDI metrics are: MDI:MLR – Media Loss Rate : Were any MPEG packets dropped
MDI:DF – What is the buffering requirements for these packets
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 100
Understanding MDI:DF (Delay) Difference between the arrival and drain rates of a media stream.
This is largely based on the arrival of the IP flow.
As such the MDI:DF and MRV:DF will appear the same
Delay Factor is based more on RFC 3393 than on RFC-4445. The DF over an interval period represents the buffering required to
handle variations in transmission at a point in the transmission path.
To calculate delay factor the virtual buffer (VB) maximum measured delay rate has the VB minimum measured delay rate subtracted. This value is divided by the media rate over that measurement interval
DF = [VB(max) – VB(min)]/MR
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 101
Understanding MDI:MLR (Loss) MDI measurement of MLR inherently refers to the ability to detect
loss in the media stream itself representing the magnitude of a loss event.
In VidMon, MLR is calculated by monitoring discontinuities in the MPEG TS headers of a packet.
The Continuity Counter (CC) exists in each MPEG header and is a rolling 4 bit counter unique to each program (PID).
IP UDP RTP I EEE
Transport Headers
… … Adaptation Control Field
Continuity Counter … …
Adaptation Control Field
Continuity Counter
Could represent the same or Different Program PID
MPEG Frame IP Payload
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 102
Regional Network"
Cisco 7600
Cisco 7600
Backbone"
CRS-1
Headend"
CRS-1
DCM
Hub"CMTS
GQAM /XDQA
Cisco 7600
Regional "Headend"
DCM
DNCS
Hub"CMTS
GQAM /XDQA
Preserving QoE MDI Monitoring
MDI: MDI: MDI: MDI:
Problem Detected!
1) Video quality problem detected.
3) Troubleshoot location where MDI first degrades. 2) Measure Media Delivery Index (MDI) at each router between receiver and source
NOTE: MDI is a combined measure of video quality based on packet loss, jitter, latency
CDS Vault/ Content Acquirer
CDS TV or Internet Streamer
CDS TV or Internet Streamer
CDS Service Router
Problem Isolated
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 103
Regional Network"
Cisco 7600
Cisco 7600
Backbone"
CRS-1
Headend"
CRS-1
DCM
Hub"CMTS
QAM
Cisco 7600
Regional "Headend"
DCM
DNCS
Hub"CMTS
QAM
MDI: MDI: MDI: MDI:
Problem Detected!
1) Video quality problem detected.
3) Troubleshoot location where MDI first degrades. 2) Measure Media Delivery Index (MDI) at each router between receiver and source
4) Correct problem and restore video quality.
MDI: MDI:
Problem Solved!
NOTE: MDI is a combined measure of video quality based on packet loss, jitter, latency
CDS Vault/ Content Acquirer
CDS TV or Internet Streamer
CDS TV or Internet Streamer
CDS Service Router
Problem Isolated
Preserving QoE MDI Monitoring
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 104
Media Rate Variation: MRV
Some platforms can not measure into the media payload of an IP packet to calculate medial loss.
Some payload types, such as SDI, HD-SDI are not candidates for a metric such as MDI.
An alternative approach is to measure loss as a function of the L3/L4 header.
For Constant Bitrate Flows (CBR) a normalized bit arrival rate can be created based on the known media arrival rate.
The Video flow is monitored for variations in the arrival rates which represent perturbations caused by excessive delay or loss in the media flow.
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 105
Measure CBR Flow Arrival Patterns
(Keohane, 2009)
Normal Case
Error Case
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 106
RTP Loss & Delay
RTP headers can be use in the delivery of video media in an IP network.
RTP headers include a sequence number which can be used to track loss and a timestamp that can be used to calculate delay.
RTP would likely not be reported as an MDI metric since it represents discrete measurements.
IP UDP RTP I EEE
(Keohane, 2009) Transport Headers MPEG
Headers MPEG Payload
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 107
Market for RTP Measurements
RTP is an ideal candidate for measuring loss in IP transport.
RTP is independent of the Video Media type in the payload
Beneficial in uncompressed video transports and non-MPEG video transports
RTP is not currently widely deployed in the MSO market while more prevalent in the Wireline market.
Newer Video over DOCSIS IPTV applications will likely be RTP based however we are early in the adoption of that technology.
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 108
Key Takeaways A systems view is increasingly important to architect
networks for SP Video
Advanced network resiliency mechanisms are available to design lossless Video transport
Video-layer-to-Network linkages offer significant benefits and differentiation
Video monitoring (esp. In-line) monitoring is very beneficial to Service providers
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 109
Q&A
Questions ?
© 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 110