Architectures and Technologies for Optimizing SP Video Networks

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

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


How do you get your TV today ?


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, ...

IPTV Architecture – View from space

“Glass to glass” experience


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

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


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

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

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


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


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


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


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

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


Access Independence

One headend, one IP network
Multiple access networks, Multiple screens


Video-to-Network
layer Linkages


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

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


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

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


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


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


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

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

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

26

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

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


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)


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


End-to-end protocol view
digital (non DOCSIS) cable

Headend / regional
PE-AGG HFC
Cable STB
eQAM HFC

PIM-SSM (S,G) joins
IGMP membership
Video Stream

Opt. MPLS: LSM / mLDP RSVP-TE IGMP:
{Limits} IGMP
Source
{Static-fwd} snooping
Redundancy PIM-SSM PIM-SSM PIM-SSM


End-to-end protocol view – Layer2 Agg

Headend / regional Eg:
PE-AGG
DSLAM Home STB
Gateway
L2
access

PIM-SSM (S,G) joins IGMP membership

Video Stream

Opt. MPLS: LSM / mLDP RSVP-TE
IGMP: IGMP IGMP IGMP
Source IGMP
{Limits} snooping Proxy
Redundancy PIM-SSM snooping
{Static-fwd}
PIM-SSM


Network Resiliency
Video-to-Network layer
Linkages


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

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


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

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


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


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


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     

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 

Quality of Service
Linkages


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

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.


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


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


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.


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.


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.


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


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


Example

QoS Classes to Queue Mapping


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


Resiliency High-
Availability
Linkages


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)

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

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

…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


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


Source Redundancy (Duplicate Streams)

S1,G S2,G

STB I’m responsible
for dropping
duplicate packets


Source Redundancy (Server Heartbeat)

S1,G S2,G

STB I will only receive
one stream at
a time


Source Redundancy (Server Heartbeat)

X
S1,G S2,G

STB I will only receive
one stream at
a time


Native IP Multicast Video Triple Play
Redundancy : Video Source Failure
Source Service Edge National Backbone Regional Backbone Residence

Primary

X
Source 1
Heartbeat

Regional
Backbone

Secondary
Source 1

P P

Primary PE
Source 2
PE
P P PE
Heartbeat

Regional Backbone PE

P P PE
PE
Secondary PE
Source 2
P P

Primary
Source 3
Regional
Backbone
Heartbeat

Secondary
Source 3


Source Redundancy (SSM)

S1,G S2,G

S1,G Join

S1,G IGMPv3 Report
STB I’ll try the Primary
source, S1,G.


Source Redundancy (SSM)

X
S1,G S2,G

S2,G Join

S2,G IGMPv3 Report
STB It appears the Primary
source failed. I’ll switch to
the Secondary source,
S2,G.


Anycast Sources

1.1.1.1 1.1.1.1

v2 join v2 join

I will send join I will send join
to the nearest to the nearest
1.1.1.1/32 1.1.1.1/32

IGMP Report IGMP Report
STB STB


Anycast Sources

X
1.1.1.1 1.1.1.1

v2 join

I will send join
to the nearest
1.1.1.1/32

STB STB


Source Redundancy
Anycast/Prioritycast policies

Policies Src A Src B
primary secondary
Anycast: clients connect to the closest instance of 10.2.3.4/32 10.2.3.4/31
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

Rcvr 1 Rcvr 2
Example: prioritycast with
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential
Prefixlength announcement 68

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


Anycast-Source with RIPv2 Update
redistribute
s/32, m=1 s/32, metric 5 s/32, m=16
1 s 1 s
ENC ADP X
ENC ADP

s/32, m=1 s/32, m=1
2 s 2 s
ENC ADP ENC ADP
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


Native IP Multicast Video Triple Play
Redundancy : Source Router Failure
Source Service Edge National Backbone Regional Backbone Residence

Primary
Source 1
Heartbeat

Regional
Backbone

Secondary
Source 1

X
P P

Primary PE
Source 2
PE
P P PE
Heartbeat

Regional Backbone PE

P P PE
PE
Secondary PE
Source 2
P P

Primary
Source 3
Regional
Backbone
Heartbeat

Secondary
Source 3


Multicast Group Based : Multi-path Load
Splitting
BEFORE (S,G1)
Active Video
Server

R3
(S,G1) (S,G2)
Heartbeat

(S,G2)
(S,G3) Source Based
(S,G4) R1 Load Splitting R5
Standby
(S,G3)
Video Server R2

Hash based on Source R4
(S,G4)

Requires unique sources for load splitting Links Unused

Now Active Video (S,G1)
Server

R3
(S,G1) (S,G2)
Heartbeat

(S,G2)
(S,G3)
(S,G4) R1 Source + Group Based
Load Splitting R5
Standby
(S,G3)
Video Server R2

(S,G4)
R4
Hash based on S,G
All Links Efficiently Used!

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 Not Applicable 
(MPLS TE)

Multicast sub-second  Not Applicable
convergence

L2 Pseudowire  


Security
Linkages


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


.. 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


Multicast Admission control
IGMP/MLD Limit Commands
What does it do ? unlimited IGMP/MLD max Memory
Resources
Gasp!
Table
• Sets quota on the number of cached

IGMP/MLD

Utilization
Memory
Entries
entries in IGMP/MLD tables

Total
• Channel Offering Limits in household
Other Processes
0 0
How it works: t1 t2 tn t1 t2 tn
time time
•  Time = t1, router receives valid
IGMP/MLD Join(s), populates table(s)
and allocates required memory
•  Time = t2, router suddenly Valid Periodic Malicious
receives malicious IGMP/MLD Join(s) IGMP/MLD Reports IGMP/MLD Reports
and table(s) quickly begins to grow
•  Time = tn, all memory resources are
exhausted and router is unable to time = t1 time = t2

service other processes requesting
more memory
•  Now, user sets IGMP/MLD limit

•  Denial of Service has been mitigated!


Ethernet Access Security Threats
Attack targets can be divided into three main categories:

Subscribers Switches Infrastructure
Layer 2 service isolation L2 Control Protocol Attack Man-in-the-Middle attacks on
across switches (STP, CDP, VTP, etc…) critical management traffic

Non intentional forwarding of MAC Flooding / Overflow Unauthenticated access to
traffic between UNI ports the switch configuration file
DHCP Rogue Server MAC Flooding / Overflow Unconfigured Ports providing
network access
IP MAC Address Spoofing Unicast, multicast, or Unauthorized network
broadcast storms access, junk traffic
ARP Spoofing (Man-in-the- Infected users flooding the Unauthenticated network
Middle) network / Malicious users access by client devices
attacking the Priority traffic
queue


Common Security Recommendations
How to Secure the Network Against Attacks

Leading Practice Category Examples Protects Against Threats

ICMP redirects, CDP, IP Source
Disable Unnecessary Services Reconnaissance, Denial-of-Service
Routing
TACACS+, Radius, Password
Control Device Access Unauthorized Access
Encryption
Disable unused interfaces, VLAN
Secure Ports and Interfaces Reconnaissance, Denial-of-Service
Pruning

Secure Routing Infrastructure MD5 Authentication, Route Filters Denial-of-Service

Secure Switching
Port Security, Storm Control Denial-of-Service
Infrastructure

Control Plane Policing (CoPP),
Control Resource Exhaustion Denial-of-Service
Hardware-based Rate Limiters

Policy Enforcement uRPF, iACLs IP Spoofing, Denial-of-Service

MAC Forced Forwarding, Virtual
Reconnaissance, MAC Spoofing,
DSLAM MACs, DHCP Option 82, IGMP
Theft-of-Service
Whitelist


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)

MAC Forced Forwarding on DSLAM
Subscriber Isolation
Private VLAN/PVLAN Edge on Switch

Rogue DHCP Server DHCP Snooping

Virtual MAC Addresses on DSLAM
Prevent MAC/ARP Address Spoofing
DHCP Snooping + ARP Inspection on Switch
IGMP Whitelist on DSLAM
Prevent Theft of BTV Service
IGMP Profile/Access-group on Switch
DHCP Snooping + IP Source Guard (IPSG) on
IP address spoofing
Switch

Limiting No. of Channels/IGMP/Multicast IGMP State limits/max-groups Multicast limits on
states Switch


Layer 2 Leading Practices
How to Secure the Network Against Layer 2 Attacks
Attack Defensive Features/Actions

MAC Attacks
Port Security, Per VLAN MAC Limiting
(CAM Table Overflow)

Broadcast/Multicast Storm Attacks Storm Control Thresholds

Hardware Rate Limiters, Control Plane Policing,
L2PDU DoS Attacks
Storm Control Thresholds
Disable Auto-trunking, Use Dedicated VLAN-ID
for Trunk Ports, Set User Ports to Non-trunking,
VLAN Hopping, DTP Attacks
VLAN 1 Minimization/Pruning, Disable Unused
Ports
DHCP Starvation Attack Port Security, DHCP Snooping,
DHCP Rogue Server Attack 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 Rate-limiting, Priority policing
queue

ARP Man-in-the-Middle Dynamic ARP Inspection

Infrastructure Security Leading
Practices

Security Threats
Man-in-the-Middle attacks on critical Out-of-Band Management, SNMPv3,
management traffic SSH, per-command AAA

Unauthenticated access to the switch Password recovery disable
configuration

Unauthenticated network access by client 802.1x
devices

Unconfigured Ports providing network UNI Default Port Down
access

Unauthorized network access, junk traffic Access Lists


Visual Quality of
Experience
Linkages


Improving Cisco IPTV Experience Visual
Quality
Experience
Non-Stop Visual Quality Experience (VQE) Technology (VQE)

Aggregation
Router

• Caches all Video channels
• Retransmits lost packets to STB
VQE Server

Access Node Access Node

Noisy Last Mile

Without VQE VQE Enabled


Channel change Events Summary
Wait for arrival of PSI – PAT, PMT, CAT
Jitter buffer full Wait for arrival of I-frame
Start filling jitter buffer

SW recognizes UDP pkt STB MPEG buffer processing complete

1st UDP packet arrives at STB

* t=0

STB Network STB STB MPEG Buffer STB

STB starts decode
Leave/Join/Network Latency
Video/Audio is played
STB sends IGMP join (wire)
Channel change complete
STB sends IGMP leave (wire), clear old buffers
SW starts channel change
User hits channel STB Related to STB implementation
change on remote
NetworkRelated to network delays
STB
Not to scale* Related to STB MPEG buffer
MPEG

Sample Channel change time calculation
AVC/H.264 SD on IPTV DSL
Channel Change Latency Typical Cumulative
Device/Location
Factor Latency Latency
1 Send IGMP Leave for channel X STB 10 ms
2 Send IGMP Join for channel Y STB 10 ms
DSLAM gets Leave for channel
3 DSLAM/Network 10 ms
X
4 DSLAM gets Join for channel Y DSLAM/Network 10 ms ~ 20 - 40 ms
DSLAM stops channel X, and
5 DSLAM/Network ~ 30 – 50 ms ~ 50 – 90 ms
sends Channel Y
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

Optimizing Channel change time – Page 1

Device Optimization Factors

  GOP length tuning
Encoder
  Tuning PAT/PMT intervals (if supported)

  Tuning of ECM intervals (PMT)
Conditional Access
  Key rotation timeframe

Residential Gateway   Tuning IGMP timers
#
(RG)   Video-optimized QoS config

  Cache PAT/PMT
STB
  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

Optimizing Channel change time – Page 2
Device Optimization Factors
#
  Video-optimized QoS config (marking, scheduling
Headend Router
etc)
#
  Secured control plane (PIM/IGMP limits, Control
Core Network Elements plane policing, Hardware rate-limiters etc)
#
  Video-optimized QoS config

  IGMP static joins for popular channels
Distribution/Aggregation #
  Video-optimized QoS config
Network Elements   Secured control plane #

  IGMP Fast/Immediate leave
Access Network Elements   Tuning IGMP timers (Query time etc)
(DSLAM/MetroE switch/   Explicit IGMP Host tracking (IGMPv3)
#
PON)   Video-optimized QoS config
#
  Secured control plane

# Not a direct contributor to reduce zap time. But, helps reduce
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential
response variability and enables better treatment for Video 88

Visual

Cisco IPTV Fast Channel Change Quality
Experience
(VQE)
Combined VQE Unicast stream Client Early Channel Change!
Set-Top Box
•  Caches all Video channels
Access Node
•  Bursts Video streams to STB VQE Server
starting with I-frame + Early Channel
Aggregation Start VQE
Router
+ I-frame burst

Combined Cisco Fast
Channel Change:
Average: ~0.7 sec Un-optimized channel
Variance: ~0.4 sec change time stats:
Average: ~2.2 sec
Variance: ~1.2 sec


Admission Control
Linkages


Video
Media-aware IP NGN Admission
Control
Video Call Admission Control (CAC)
End-2-End Video CAC (RSVP-based)
Video Streams
7600
ASR9000

VoD TV

Video Quality Fantastic Video Quality Suffers (for ALL users) Gracefully Rejects 3rd VoD Stream

2 VoD Streams—4Mbps Each 3 VoD Streams—4Mbps Each 3 VoD Streams—4Mbps Each
with Video CAC
10 Mbps 10 Mbps 10 Mbps
ps ps
ps 4 Mb 4 Mb
4 Mb
4 Mbps 4 Mbps
4 Mb 4 Mb
ps ps
4 Mb
ps


Network Call Admission Control
Avoiding Congestion Packet Loss
Broadcast TV Policy
Multicast CAC Server

2 Channel request Cisco Broadcast
Source
7600
Multicast
CAC
IPTV
1 Channel
4 Request Denied/ Available Available
Change
Accepted Bandwidth 3 Bandwidth
Check Check

Video on Demand Policy
Unicast CAC Server

2 Channel request Cisco
VoD Servers
7600
RSVP-CAC

VoD
1 Request 4 Request Denied/ Available Available
Accepted Bandwidth 3 Bandwidth
Check Check

Against a DiffServ prioritized percentage of link bandwidths

Pure On-Path CAC for VoD
Synchronisation between RSVP and VoD streaming

Middleware VoD
Entitlement Sys Controller
1 Session Mgt, EPG
3
2
eg RTSP
Business
Access Carrier Ethernet Aggregation Edge Multiservice Core
Corporat
e Content Network
BNG
Residential
VoD
4
VoD TV SIP
Ethernet
Access Node Aggregation Distribution RSVP Path VoD Stream

STB Node Node MSE
Business

Corporate Ethernet
6
Access Node Aggregation Aggregation Network
Residential Node
IP Core Network
IP / MPLS

STB Aggregation
DSL Node Distribution MSE
Business
Access Node
Node
Corporate

RSVP Resv
Residential
Aggregation
BNG
5
Node VoD
PON
Access Node
STB

CAC CAC CAC

Pure On-Path CAC for VoD
Synchronisation between RSVP and VoD streaming

See draft-ietf-tsvwg-rsvp-proxy-proto
Middleware VoD
Entitlement Sys Controller
1 Session Mgt, EPG
3
2 7
eg RTSP
Business
Carrier Ethernet Aggregation
eg RTSP
Edge
Corporat
Access Multiservice Core
e Content Network
BNG
Residential
VoD
4
VoD TV SIP
Ethernet
Access Node Aggregation Distribution RSVP Path
STB Node Node MSE
Business

Corporate Ethernet RSVP PathErr
Access Node Aggregation Aggregation Network
Residential Node
IP Core Network
5 IP / MPLS

Aggregation
RSVP Resv
STB
DSL Node Distribution MSE
Business
Access Node
Node
6
Corporate

Residential
Aggregation
Node VoD BNG
PON
Access Node
STB

CAC CAC Reject

Video Quality
Monitoring/
Assurance
Linkages


Video/IPTV Quality Measurements (What Can
Go Wrong)
Error Problem
Type Area
Visual
Control Measures Control
IGMP Latency, RTSP Latency, Plane
Channel Zap Time QoE
Problem
Errors
Content Impacts
Content Measures Customer
Control

Picture Quality, Blocking, Blurring,
MPEG-TS Visual Noise, Audio Drop-outs
Video
Problem
RTP Media Transport Measures
PCR Jitter, Pixelization,
Sync Loss, Continuity Errors QoS
UDP Errors
Impacts
Operator
IP
IP Network Measures IP
Packet Loss, Jitter, Delay Problem
Physical Ethernet


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.


The VidMon Metrics
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 MPEG
Header Payload

Example Video Packet in over an IP Transport

Transport IP UDP RTP FCS
UDP Video Payload Content
(MPEG is not the only payload option)


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


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


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).
Could represent the same
or Different Program PID

Adaptation Adaptation

… Control
Field
Continuity
Counter … … Control
Field
Continuity
Counter …

I
E
RTP UDP IP E
E

Transport
MPEG Frame IP Payload Headers

Preserving QoE
MDI Monitoring
NOTE: MDI is a
combined measure of
video quality based on
packet loss, jitter, latency
MDI: MDI: MDI: MDI:
CDS TV or
HubInternet Streamer Regional Network Regional Backbone Headend
Problem Headend
CMTS
Detected! Cisco CRS-1
Cisco 7600 DCM
7600 DCM
GQAM
/XDQA
Problem
Isolated
CDS Service
Hub Router
CMTS Cisco
7600

CRS-1
GQAM
/XDQA CDS TV or DNCS CDS Vault/
Internet Streamer
Content Acquirer

1) Video quality problem detected.
2) Measure Media Delivery Index (MDI) at each router between receiver and source
3) Troubleshoot location where MDI first degrades.

Preserving QoE
MDI Monitoring
NOTE: MDI is a
combined measure of
video quality based on
packet loss, jitter, latency
MDI:
MDI: MDI:
MDI: MDI: MDI:
CDS TV or
HubInternet Streamer Regional Network Backbone Headend
Problem Regional
Solved!
Detected!
CMTS
Headend
Cisco CRS-1
Cisco 7600 DCM
7600 DCM

QAM
Problem
Isolated
CDS Service
Hub Router
CMTS Cisco
7600

CRS-1

CDS TV or DNCS
QAM CDS Vault/
Internet Streamer
Content Acquirer

1) Video quality problem detected.
2) Measure Media Delivery Index (MDI) at each router between receiver and source
3) Troubleshoot location where MDI first degrades.
4) Correct problem and restore video quality.

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.


Measure CBR Flow Arrival Patterns

Normal
Case

Error
Case

(Keohane, 2009)


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.

I
E
RTP UDP IP E
E

(Keohane, 2009) Transport
MPEG MPEG Headers
Presentation_ID © 2007 Cisco Systems, Inc. All rights reserved. Cisco Confidential Payload Headers 106

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.


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


QA

Questions ?


Architectures and Technologies for Optimizing SP Video Networks

More Related Content

What's hot

Viewers also liked

Similar to Architectures and Technologies for Optimizing SP Video Networks

Recently uploaded

Architectures and Technologies for Optimizing SP Video Networks