Top Banner
eBook Video Conferen cing, The Enterprise and Y ou Video conferencing knowhow without the computer science degree 
39

Video Conferencing eBook

May 29, 2018

Download

Documents

onemesis
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 1/39

eBook 

Video Conferencing,The Enterprise and You

Video conferencing knowhow without the

computer science degree 

Page 2: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 2/39

eBook 

www.VideoOverEnterprise.com December 2008 | 1

IntroductionComputers have changed our lives by promising - and delivering - seemingly limitless innovation, from

word processing to the Internet.

Indeed, technology has even managed to honor the one pledge enterprises around the world were

hoping for: the ability to join virtual meetings with your peers and partners from anywhere, at any

time and thus reduce travel costs and increase productivity.

Though the hype around it has been quite exaggerated, video conferencing has grown consistently in

market share. Advances in processing power, available bandwidth and video coding technology,

coupled with the current economic slowdown and the "green" movement place video conferencing in a

good position to grow faster in market share and fulfill its potential to offer high definition, easy-to-

use, on-demand videoconferencing.

More and more companies are either deploying or considering deployment of visual communication

services. Still, there seems to be a great lack of knowledge regarding video conferencing at

management levels – what exactly is it, what would be the benefits and what are the hurdles of 

deploying it within an organization.

This eBook tries to tackle these issues by answering several simple, yet frequently asked questions:

• Why is there any need to deploy visual communication services?

•  What is video conferencing anyway?

•  What does it take to deploy visual communication services?

•  How do I know if my infrastructure is ready for visual communication services?

For those who wish to dive deeper into the exciting world of visual communication and learn more

about the technological aspects of this technology, there is an additional chapter. It gives some

insights about the obstacles in video transmission over corporate networks as well as current industry

trends of video coding techniques.We hope you will enjoy this eBook.

Page 3: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 3/39

eBook 

www.VideoOverEnterprise.com December 2008 | 2

Table of Contents

Introduction ........................................................................................................... 1 Acronyms and Glossary ............................................................................................... 3 

Frequently Used Acronyms ........................................................................................ 3 Video Glossary ...................................................................................................... 3 

The Benefits of Using Video ......................................................................................... 7 The Different Types of Office Communication Means ........................................................ 7 The Benefits of Deploying Video Communications in the Enterprise ...................................... 10 How Does Video Really Work in an Enterprise? ............................................................... 11 Video Conferencing Truly Exists ................................................................................ 12 

What Does it Take to Deploy Video? .............................................................................. 15 I feel the need, the need for speed ............................................................................ 15 High Definition is Next. Do YOU Know How Much Bandwidth You Have?! ................................. 17 

What Can I Know About My Network? ............................................................................. 20 Testing Your Network’s Video Capabilities has now Become eVident. .................................... 20 

Advanced Topics ..................................................................................................... 23 Visual Artifacts in Video over IP ................................................................................ 23 Codec Manipulation in Visual Communication ................................................................ 29 Scalable Video Coding and the Future of Video Conferencing .............................................. 31 

About The Author .................................................................................................... 35 RADVISION’s Video Offering ........................................................................................ 35 

SCOPIA Unified Communications Video Infrastructure ....................................................... 36 

Page 4: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 4/39

eBook 

www.VideoOverEnterprise.com December 2008 | 3

Acronyms and Glossary

Frequently Used Acronyms

TP - TelePresence

HD – High Definition

HDVC – High Definition Video Conferencing

HW – Hardware

SD – Standard Definition

ITU – International Telecommunications UnionUC – Unified Communications

KISS – Keep it simple stupid

MCU – Multipoint Conferencing Unit

IPTV – Internet Protocol Television

CIF – Common Intermediate Format

IP – Internet Protocol

IMS – IP Multimedia Subsystem

CIF – Common Intermediate Format

Video Glossary

Video Encoder: Software or HW device that enables video

compression. Generally, compression is used to reduce the size of 

the visual content, either for storage purposes or for streaming over

a network channel (reduce bit rate). Video encoder performance and

quality is being determined by the encoder complexity.

Video Decoder: Software or HW device that enables video

decompression. In general, a video decoder is used to reconstruct

the video content from compressed data into a visible displayed

format. For real time streaming network applications, the decoder is

used to convert video packets sent over the network into video

frames which can be displayed on screen.

Page 5: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 5/39

eBook 

www.VideoOverEnterprise.com December 2008 | 4

Bit rate: Rate of bits transmitted over a particular period of time on a specific channel. In video

coding applications, video bit rate is determined by the number of the used bits per one second. For

example: 1Mbps = 1Megabit (1 Million bits) per second.

Frame Rate (fps): Rate of frames used in one second of video stream.

Frame resolution: A term defining the size of the basic element of a video content – the frame.

Frame resolution describes the number of pixels on the horizontal and vertical axis of a video frame.

There are several predefined popular acronyms for frame resolutions: CIF – 352x288 , 4CIF - 704x576,

D1 – 720x480 (NTSC) or 720x576 (PAL), 720p – 1280x720.

PAL: A term that uses to describe a playback video on a PAL TV. In general, PAL refers to standarddefinition (SD) video with vertical resolution of up to 576 pixels and horizontal resolution of up to 720

pixels. PAL frame rate is 25 fps. PAL broadcasting can be found in Western Europe countries,

Australia, some countries of South America and some Asian countries.

NTSC: A term that uses to describe a playback video on a NTSC TV. NTSC generally includes standard

definition (SD) video with vertical resolution of up to 480 pixel and horizontal resolution of up to 720

pixels. NTSC frame rate is 29.97 fps. NTSC is used in United States, Canada, Japan, and various Asian

countries.

High Definition: Refers to frame resolutions of 720p and up.

Frame Types: In video coding, there are several common frame types:

•  I or Intra frame is a frame that is coded independently of any other frame, using only spatial

redundancies for prediction and coding. An I-frame uses relatively more bits comparing to

other frame types. I frame coding complexity is relatively less than other frames type.

•  P or Inter frame is a predictive video frame. This coding is done according to predictions made

on the current frame following the previous I or P frames. A P frame is coded by usingtemporal redundancies from the previous frame. P frame uses relatively less bits than I frame

and its complexity is higher.

•  B frame refers to a Bi-directionally predicted frame and requires information from previous

and following I, P or B frames. B frame uses relatively less bits than all other frame types and

its coding complexity is greater than all other frames types. Usage of this type of frame

introduces system delay. Hence, it is not popular in real time low delay applications.

Page 6: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 6/39

eBook 

www.VideoOverEnterprise.com December 2008 | 5

Picture Aspect Ratio: Representation of an image width to its height. A general notation is the form

of X:Y where X represent the image width and Y represent the image height. While there are several

video standards that are currently used in video applications, it is necessary to keep aspect ratio when

converting from one display standard to another. Avoiding that may cause the resulted frame to look

distorted, squeezed or stretched.

Packet Loss: Packets are units of information sent across a packet switched network from their source

address to a destination. Packet loss occurs when one or more packets fail to reach their destination.

On network protocols such as UDP that provides no recovery mechanism for packet loss, applications

should handle that error efficiently and should be able to conceal the lost data. In video conferencing

applications, packet loss is the major encountered error type that reduces video quality and quality of 

service.

Video Codecs/Standards (H.26x, MPEG-x, WMV x, Real Video, VPx): Video coding standards are usedin order to standardize the video codecs. Some of those widely used standards are specified in the

international standards while others are based on proprietary standards.

H.26x refers to ITU standards while the MPEG-x term refers to ISO/IEC standards.

WMV (its latest version known as VC1) is a Microsoft standard for high efficiency video coding.

RealVideo is a popular video codec, developed by RealNetworks mainly used in PC and mobile

applications. VPx is a proprietary video codec, developed by On2 Technologies and is commonly used

by Adobe flash player and internet video platforms. Common MPEG codecs are MPEG 2 and MPEG 4.

MPEG 2 is widely spread as a popular storage and broadcasting codec. MPEG 4 and its derivatives are

common in mobile device applications as well as storage formats, and supported by many DVD players.

Common H.26x codecs are H.263 and H.264. H.263 is widely used by video conferencing applications.H.264 is a joint development ofITU and ISO/IEC and currently, is the latest video standard available in

the industry. H.264 goal was to provide good video quality at substantially lower bit rates than

previous standards without increasing the complexity of design.

Lossy compression: A term used to describe a compression method where the compressed data

cannot be reconstructed exactly as the original form. This type of compression is mainly used in visual

and audio applications where a partial loss of data is acceptable by the human visual and hearing

systems. As opposed to a lossless compression where the compressed data can be reconstructed

precisely, lossy compression methods require significantly less bits in the compressed form.

Jitter: A term used to describe the variation in packet delay. In packet switch applications, where

data is carrying over network packets, there is a variance in the packet arrival timing. In order to

overcome this variance and to provide a smooth usage of the received packets, a delay buffer is added

to the system. In most cases, the buffer size is being determined by the max introduced variance.

Page 7: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 7/39

eBook 

www.VideoOverEnterprise.com December 2008 | 6

Lip Sync: A term refers to the relative timing of audio and video portions during playback. In general,

it used to describe the matching lip movements with voice. Generally, human perception is sensitive

to non synchronized audio and video with a relative phase of ~100 msec. In contrast, there are some

people that are sensitive to much lower durations.

Video Artifacts: The big challenge in most video applications is to provide the highest video quality

with a minimum cost of bit rate. As a result of lossy compression techniques, non optimized network

conditions and other application restrictions, video quality is affected and quality of service may

reduce. Video artifacts may be generated from non optimal settings and environment characteristics,

causing an unpleasant visual view. The most popular video artifact is the quantization noise,

generated as a result of bit rate reduction. Network packet loss, when accruing frequently, increasing

the video artifacts dramatically. Other artifacts like ringing noise, blocking effects, blurred images,

un-sharpness and more are resulted from the codec processing and for some cases, may be

compensated with post processes after the decoder task.

Page 8: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 8/39

eBook 

www.VideoOverEnterprise.com December 2008 | 7

The Benefits of Using Video

The Different Types of Office Communication Means

When it comes to office communication, the tools people use on

a daily basis as part of their job is chosen by their employer and

their selection is therefore limited. However, when you carefully

inspect one’s daily communication behavior, it seems that e-mail

and voice are still king, and Cisco’s recent acquisition of e-mail

client vendor PostPath proves it. Instant Messaging (IM) is the

fresh prince of corporate air, while visual communications – video

conferencing– is the new kid on the block. It has started to be

deployed on corporate networks, but its adoption is slow.

Everyone seems to be asking the billion-dollar question:

What will be the office communication means of choice in a year, two years or five?

What happens if we look at it from a different perspective: Different communication means give

different experience to users. So why not use them all?

Any kind of network based communication service between people can be defined by a set of six

parameters:

Bandwidth How much bandwidth does this communication service require?

Immediacy Services are either synchronous, where you expect to get a response or a feedback

immediately, or asynchronous, where feedback is either unexpected or can be

delayed.

Direction Services are either unidirectional (you get a feed of data but can’t respond to it) or

bidirectional, where both sides of the “conversation” participate.

Participation How many people on each “side” of the service exist (1:1, 1:N and even M:N).

Ease of Use How easy is it to use the communication service in question.

Collaboration Which level of collaboration does this communication service offer.

Page 9: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 9/39

eBook 

www.VideoOverEnterprise.com December 2008 | 8

Here’s how the office communication means discussed above measure up:

E-Mail IM Voice VC HDVC/TP

Bandwidth Low Low Low Medium High

Immediacy Asynchronous Synchronous1  Synchronous Synchronous Synchronous

Direction Unidirectional Bidirectional2 Bidirectional Bidirectional Bidirectional

Participation 1:13 1:14 1:15  N:N N:N

Ease of Use Easy Easy Very Easy Less Easy Less Easy

Collaboration Medium Medium Low High Very High

The above can be roughly divided into three groups:

1.  E-mail - Although inferior in most parameters, it is an easy to use, low bandwidth,

collaborative tool. Therefore it is no surprise that it became the de-facto standard for

corporate communication.

2.  IM, voice – They are easy to use, low in bandwidth, and offer an easy and therefore very good

experience (synchronous, bi-directional). Again, it is no wonder EVERYONE is using the phone

and IM client.

3.  Visual Communications – It is not really important if we are talking about Video Conferencing,

High Definition Video Conferencing or Telepresence. They consume large amounts of 

bandwidth (some more than others), and although they offer great features (N:N connectivity,

for instance), they are harder to use and less intuitive. Therefore, they are still not as popular.

If you want to send a colleague a message with a rather large amount of data and immediacy is not

top priority, e-mail would remain the best solution. It’s easy, quick and it does the job.

If there is a need for immediacy and bi-directional experience is important, one has a choice between

voice and IM. Voice is more personal, but has a lower level of collaboration (no data).

1 IM is considered to be Synchronous, but one may argue that if the other party’s client is closed and/or theother party is unavailable, it is an asynchronous experience.

2 IM is considered to be Bidirectional, but one may argue that if the other party’s client is closed and/or theother party is unavailable, it is a unidirectional experience.

3 E-mail can be a 1:1 as well as a 1:N experience, depending on the type of e-mail chosen.

4 IM is usually a 1:1 service, but today’s IM clients can broadcast IM messages in a 1:N mode as well.

5 POTS is usually a 1:1 service, but today’s PBXs offer N:N services as well.

Page 10: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 10/39

eBook 

www.VideoOverEnterprise.com December 2008 | 9

If a high level of collaboration is essential, visual communication is a necessity. Depending on the

level of in-person interaction expected, and the resource (bandwidth, equipment) availability policy in

the organization, one can choose between legacy, high definition or next-generation video

conferencing systems.

Page 11: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 11/39

eBook 

www.VideoOverEnterprise.com December 2008 | 10

The Benefits of Deploying Video Communications in the

Enterprise

Unified Communication (UC) is one of the hottest buzz words in the IT market, potentially in the

entire tech market. Ask a few people what UC is, and you’ll be sure to get various answers. Still, most

agree, it involves uniting existing communication systems and tools (phone system and internet) with

more advanced productivity and communication tools (such as instant

messaging, video conferencing, and web collaboration) to deliver a

complete solution.

Bottom line - UC is aimed at creating adaptive workspaces – allowing

for workers to collaborate across any workspace, accelerating decision

making and endorsing innovation across the organization. Sounds

great? Well, a recent Forrester Research study which questioned 2,187

Western companies that were potential buyers of UC technologiessuggests that 55% of those queried claimed that there is “confusion

about the value of unified communication for their company”.

This “confusion” leads to “no increase in firms buying UC… because

they’re not able to define it very clearly…” At the same time however

40% of those firms have already deployed IP audio and IP web conferencing, 37% have deployed video

conferencing, and those adoption figures continue to rise. You can now see that this is indeed

somewhat confusing.

Parker claims that audio, web and video conferencing are “well within the definition of UC”, but let’s

put the definitions aside for a moment and suggest this. Instead of seeking out a “total” UC solution,

waiting for standards to mature and prices to be lowered, or for that single compelling application to

emerge, why not deploy a video conferencing system first and take that first solid step towards a truly

adaptive workspace today?!

I’m a big fan of desktop video conferencing solutions, and so are most

leading research and analyst groups (Frost & Sullivan, for example). If I

was an IT manager, I would definitely go with desktop video

conferencing before deploying a complete unified communication

solution in my organization, and here is why:

•  KISS - Start with a mature, proven technology, instead of diving

into the undefined, chaotic world of UC. See technology workfor you, then progress.

•  Setup time - Deploying desktop video in the organization is easy. Connect a webcam (in case

it’s not there already), click on a URL, quickly download and install, and you’re set. Hell,

employees can actually do that all by themselves!

•  Money, money, money - Desktop video hardly costs ANYTHING! UC solutions require monthly

license fees or user license fees, which cost a considerable sum of money. If you consider a

mass deployment in your organization, desktop conferencing seems like the affordable way to

Page 12: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 12/39

eBook 

www.VideoOverEnterprise.com December 2008 | 11

go.

•  Telework - Desktop video conferencing allows your employees to work seamlessly from

anywhere as if they were actually in the offices. You hardly need anything else (other than a

VPN client, an instant messaging client and an e-mail client, but you probably already have

them) to get telework to be effective in your organization.

•  ROI - Desktop video conferencing reduces travel (travel between corporate branches,

suppliers, customers, service providers) without requiring anything else. And as it costs

nothing and is simple to deploy (reason #2), the ROI is quite obvious.

•  Connectivity - Desktop video conferencing works well with your previous communication

equipment (IP phones, mobile phones, conference room system) and it works with the video

conferencing systems that you are considering (HD Video Conferencing systems,

Telepresence). It can also be enhanced to High Definition (using an HD cam and HD-enabled

client) and even supports most UC solutions that you may progress to.

So you see - with all due respect to buzz words, if you want to gain most of the UC vision while risking

and spending as little as possible, deploying desktop video conferencing is surely the right first step

for you. It’s a rather small step for an IT department (simple, doesn’t cost much and quick to

deploy), but definitely a BIG step for your organization. You don’t have to work at NASA to know it’s

the right thing to do.

How Does Video Really Work in an Enterprise?

A Release Readiness Review (RRR) meeting is standard procedure in most software companies, butwhat if your company is spread over three countries, located in three different continents with three

different time zones? Even if you could get all of them in the same place, you would still need to find

a room that could fit more than 20 people - product managers, development team leaders, QA - at the

same time?

Lucky for us, video conferencing companies such as RADVISION now offer products which are designed

to help global enterprises meet and share video, audio and data over their corporate network.

Take RADVISION, for instance. In the designated time of a typical RRR meeting in Radvision, people

from across the globe join a video conference, led by the product manager from Tel-Aviv. Some staff 

can join from the numerous conference rooms in the organization, while others connect from their

desktops using RADVISION’s desktop client (Scopia Desktop). Joining from mobile phones, and a

logging in at home homes (using either their phones or their desktops) are other frequently used

possibilities.

Page 13: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 13/39

eBook 

www.VideoOverEnterprise.com December 2008 | 12

A Typical Video Conference Architecture in RADVISION.

Without worrying about balancing the load, adjusting the bitrates and resolutions, or grouping all the

participants in a specific physical location, it is possible to go through whole presentations while

giving feedback and accomplishing the objectives of the RRR meetings. The best part about this is

that it is as easy as going to a conference room and having an actual meeting. Actually, it is even

simpler…

Many people work in global work places and multi-national enterprises, and it is a surprise every time

that these companies are “not” using any means of visual communication.

Those who already use video conferencing in RADVISION and in other global organizations all speak

enthusiastically about the benefits and effectiveness of it. Hopefully in a few years everyone will be

able to enjoy the comfort and ease of the unified communication revolution and those who took

leading roles in this will sit back with smiles knowing that they created this “new world”.

Video Conferencing Truly Exists

Video Conferencing is something every enterprise, and every employee in the enterprise, can benefit

from. Nevertheless, it is quite obvious that different enterprises, and more specifically different

employees, have diverse needs and therefore have varied requirements for video communications.

Due to these diverse needs, and also to the varied roles that exist in the enterprise, different

employees use different video conferencing equipment: Top executives can use high-end, expensive

video conferencing units, such as the LifeSize Room, with high definition video, audio and a dedicated

high bandwidth line. Company meeting rooms may include multi-screen, multi-camera, high-

definition video conferencing systems. Managers might be using lower cost video conferencing

endpoints while sitting on their desks. Employees who do not use video conferencing often may be

using software-based video conferencing applications, like web cameras and personal computers, and

utilizing the regular data bandwidth to extend visual communication to the desktop.

Page 14: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 14/39

eBook 

www.VideoOverEnterprise.com December 2008 | 13

Example: Corporate video network topology Looking at this complicated mash of different video conferencing equipment, one may wonder how a

video conference can even be conducted? It is as diverse in capabilities - image size (resolution), bit

rate, choice of video and audio codecs, etc. and therefore so broad. A low resolution endpoint can’t

interwork with a high resolution stream and a high bandwidth endpoint will have troublecommunicating with a low bandwidth endpoint. Lastly, if endpoints use different video codecs, the

call will simply not be successful.

The choice of video codec is a “weak spot” in the whole concept of video communication. One may

argue that today most endpoints support H.264, the latest video codec standardized by ISO and ITU-T

(considered to be the best known codec out there), but unfortunately it is far more complicated.

Some of the older video conferencing equipment (legacy) does not support H.264; some endpoints still

support H.261, which was standardized 18 years ago. Others use H.263; Mobile handsets supported by

MPEG4 and H.263 and only now have started to introduce H.264. Popular instant messaging clients,

such as Office Communicator and Skype, use proprietary video standards.

Page 15: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 15/39

eBook 

www.VideoOverEnterprise.com December 2008 | 14

H.261

H.263

H.263+

H.263++

H.264

      I      T

      U   -      T

      I      S      O

MPEG 1

MPEG 2

MPEG 4

Video Compression Standards

 Evolution of the video standards

Of course none of these standards are backward compatible.

In that case, believing that a video conference will work out seamlessly requires a great deal of faith.

Who - you will probably ask - is responsible for the “magic” that you see every day in your enterprise

when employees simply call into the conference without any worries? Well, the Babel fish in the

middle of the enterprise infrastructure is the video conferencing bridge, the MCU in video

conferencing jargon.

MCU, short for Multipoint Control Unit, is the network entity that is responsible for translating

between different endpoints. Therefore, it should be capable of not only accepting and understanding

every endpoint (no matter what it is and what characteristics it uses) but also translating it to any of 

the other endpoints in the conference in a process called Transcoding.

So when a top executive is using his high-end conferencing unit to call a manager on his mobile

handset, the MCU is working very hard in the middle to transcode the streams. The MCU makes it

possible for the high-end conferencing unit to send a high definition 720p resolution while using H.264

as video codec and a 4Mb per second bandwidth to the mobile handset. This sends a low resolution

stream and uses MPEG4 as video codec and a 64Kb per second bandwidth.

The example above illustrates that a reliable MCU does not force any restrictions on the endpoints

connecting to it. This means that an IT manager can choose whatever kind of endpoints to use and

expect the good old “plug and play” scheme to work. Designing such a product therefore introduces

complicated interoperability issues, on top of “just” testing new endpoints in events like the SuperOp.

Backward compatibility issues, for instance, are a big pain as they require not only support, forexample Microsoft, to support your old versions, but have to support old versions of products from

other vendors that may be used somewhere by some client.

Still, the Babel fish works its magic and as a result, video conferencing usually works seamlessly, as

long as you have a good MCU. Different users connect using different equipment and everyone gets

connected to one big, successful conference. It may seem like something that requires a lot of faith,

but the Babel fish in the Tel Aviv offices of RADVISION proves video conferencing does successfully

exist. 

Page 16: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 16/39

eBook 

www.VideoOverEnterprise.com December 2008 | 15

What Does it Take to Deploy Video?

I feel the need, the need for speed

Most telecommunications providers around the globe are busy nowadays developing Next Generation

Networks (NGN).

Millions of dollars are invested in upgrading infrastructure in order to provide internet services at

bitrates of up to 50Mbps. NGN will allow providers to use their wire-line infrastructure to provide

advanced services, such as IPTV that will compete with satellite and cable companies.

This is, of course, very interesting. As there is no such thing as more bandwidth, everyone has the

need for speed. In Israel, for instance, current internet infrastructure is quite substandard. Most

internet connections at home use speeds of up to 3Mbps for download and up to 256Kbps for upload.

In the US, for comparison, download speed at most homes already reaches 8Mbps and more whileuploads already support more than 1Mbps.

Download Speed Application Technology

56 kbps Low Quality, Streamlining Audio Dial Up

200 kbps FCC Definition of High Speed DSL Lite (256 kbps)

1 mbps Streaming Video Satellite, DSL, Cable

2-5 mbps High Resolution NeurologicalTesting

DSL, Cable

4 mbps Standard TV DSL, Cable

6 mbps Videoconferencing DSL, Cable

20 mbps High Definition TV ADSL

100 mbps All Fiber

Broadband Applications & Speeds. Source: S. Derek Turner, Broadband Reality Check, Free Press,August 2005

As one can see in the above table, most video applications require at least 1Mbps of download speed.

For HD television there needs to be around 20Mbps. In a Communication Workers of America policy

paper titled “Speed Matters - Affordable High Speed Internet For All“, the authors argue that a high-

speed interactive network on a national level will improve the quality of our economic, civic and

personal life, not just entertainment.

For instance, high speed interactive broadband can connect health professionals and patients which

Page 17: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 17/39

eBook 

www.VideoOverEnterprise.com December 2008 | 16

enable telemedicine. Programs like REACH (Remote Evaluation of Acute Ischemic Stroke) can save the

lives of thousands living in rural areas that don’t have easy access to big hospitals.

Furthermore, a recent Pew Internet & American Life Project survey shows that more than 40% of all

US adults now have a high-speed broadband internet connection at home. The demographics are as

expected, with most users are in the 30-49 age group, white, well-educated and with a rather highincome. These figures sit well with the “Speed Matters” motto: while in urban areas only 13% of the

users have broadband, in suburban areas 56% of the users enjoy it and in rural areas 31%.

In other words, it seems that broadband connection is used for its natural purpose - communication.

Whether it is used for triple-play (voice, video, internet) or entertainment services (IPTV, games), it

seems that broadband communication is the key with bandwidth as the basis for any broadband

communication.

50Mbps in the home may sound like a lot, but when you think about multi-channel, on-demand, high

definition video with real-time high-definition multi-user games and high definition video conferencing

- all in the comfort of your living room, the numbers are quite reasonable, even a bit conservative.

The need for speed

Still, upgrading from my 1.5M/256K connection at home to a 50Mbps connection would be a dramatic

change of pace. It will have a great impact on people’s lives, both personally and as a society. I can

already feel the need, the need for speed…6 

6 Tagline for the movie “Top Gun”, voted as one of the top 100 movie quotes by the American Film Institute.

Page 18: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 18/39

eBook 

www.VideoOverEnterprise.com December 2008 | 17

High Definition is Next. Do YOU Know How Much Bandwidth You

Have?!

High definition (HD) is everywhere. If you haven’t read about it, you probably have seen it featured in

a commercial. If you haven’t seen a commercial, you probably have heard about it from one of your

friends who bought a new TV. HD is the next big thing, it’s everywhere and you can’t escape it. The

question is not if HD will spread globally, but rather if we have really stopped to consider all of its

implications?

When it comes to video conferencing, there are now enough endpoints out there that support HD to

state that the market has completely gone to high def. This is not including the outrageously

expensive conference rooms, but rather the commoditized HD endpoints from vendors like LifeSize or

Aethra.

Most users would definitely enjoy the HD experience. In ideal conditions it is a definite “WOW”,

especially when compared to the small, blurred SD experience (and HD sure makes CP look better thanever). It’s bigger, it’s sharper, and you can see details you’ve never seen before.

That’s why the video conference world has “jumped” to HD (actually skipping middle resolutions such

as 4CIF). Modern endpoints and MCUs support up to 720p. Some even support 1080p, but a very

crucial part of the puzzle was somewhat neglected, bandwidth. Bandwidth, which is necessary for the

transmission of video over IP, hasn’t progressed as fast as the endpoints. Actually, it’s not only a

matter of progress, but also price. In other words, bandwidth is expensive.

If bandwidth is expensive, compression becomes a necessity. The video encoder is the unit responsible

for compressing the video to fit the bandwidth requirement. In an ideal world, this encoder would

have unlimited compression ability with no implementation problems or any visual artifacts.Therefore, a video in any resolution can be sent over any given bandwidth with no effort at all.

Unfortunately, back in the real world, even the most advanced state-of-the-art encoder used today -

H.264 - still has many limitations in terms of compression, complexity and visual artifacts. The reason

it is considered the most advanced is due to its ability to compress the same video, at the same visual

quality, to half the bandwidth required by previous encoders (such as MPEG2, H.263, MPEG4, etc.).

Still, for a good quality (or, God forbid, superb quality) 720p resolution, 30 frames per second (fps)

video conference scene (known as “talking head”) compressed with H.264, you probably need at least

1.5-2 Mbps This means that an HD endpoint that sends a 720p resolution video stream that would

require a guaranteed 1.5-2Mbps bandwidth. However, this is a ballpark number, as it depends very

much on numerous factors (such as the quality of the camera or lens, the quality of the encoder and

the complexity of the scene itself), so take it with a grain of salt. Nevertheless, the graph below

shows the visual quality that the end user can expect with a given bandwidth using H.264 encoder.

Page 19: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 19/39

eBook 

www.VideoOverEnterprise.com December 2008 | 18

Visual quality resolution vs. bandwidth using a H.264 encoder for SDIt is very clear why CIF/240p and 4CIF/480p resolution are still the most common resolutions today.

For example, a good quality video at CIF/240p would require a 512Kbps link. This is something most

users can afford. This would definitely be the norm, if video conferencing becomes a norm in the

enterprise with many video conferences are running at the same time as well. Even a good quality

4CIF/480p video is still affordable in most cases. Around 1Mbps is also not that much to “pay” for good

quality video.

Frame sizes comparison for CIF, 4CIF, 720p and 1080p

Jumping to HD introduces a very “nice” jump in bandwidth requirement. This should be quite obvious

as there is more than twice the amount of information in a 720p picture than in a 4CIF/480p picture

and five times more information in a 1080p picture. For something a bit more staggering, 1080p has

more than 20 times the information in CIF. All of this can be seen very clearly in the graph above.

Still people usually tend to forget this and expect good quality HD to consume somewhere around

Page 20: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 20/39

eBook 

www.VideoOverEnterprise.com December 2008 | 19

2Mbps, but even with 2Mbps per user, assuming there are many video users and conferences talking at

the same time, the enterprise will have to invest a lot in its IP network.

Visual quality resolution vs. bandwidth using a H.264 encoder for HD

Here comes the final and painful leap to 1080p, if you invest in a 1080p endpoint, you probably expect

superb quality (not just a “good” one). This minor experience will cost you somewhere around 6Mbps.

Seeing the required bandwidth for 720p or 1080p makes it crystal clear why HD video conferencing is

not spreading fast and is still more of an executive toy rather than a mass communication tool. Most

enterprises, even if they can afford an HD endpoint and the associated connection, can probably not

afford this in high volume. This means that, at best, there will be only a few HD endpoints in some of 

the conference rooms in the enterprise and maybe a few for the executive board.

There is also another issue. On a larger scale, the video conferencing market today is still filled with

SD (CIF or 4CIF) endpoints and the common links between sites range from 384Kbps to 2Mbps. An

enterprise and/or user that has invested in HD expects to get “the HD experience”, but is still strongly

affected by his peers - other users that attend the same conference and in the same site that share

the same bandwidth capacity. For instance, a participant connecting with a low-end endpoint, using

low resolution or low bandwidth, will send poor quality video that will look bad even on an HD

endpoint. Actually, it will look even worse on the large HD screen. Eventually the HD users will be

reduced to poor quality, not because of his endpoint or connection, but simply because of other

participants in the conference.

Even so, HD is next. HD-enabled MCU’s and endpoints are being released by all the leading vendors

and prices are dropping. Everyone agrees, soon HD will become a commodity. The bandwidth though

is a problem and it seems that it will remain a problem in the future. So, for all those who want and

are ready to invest in the HD experience, PLEASE don’t forget to invest in bandwidth. It’s just as, if 

not more important.

Page 21: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 21/39

eBook 

www.VideoOverEnterprise.com December 2008 | 20

What Can I Know About My Network?Testing Your Network’s Video Capabilities has now Become

eVident.

There are many advantages for visual communications on a global scale, most of them relevant for the

enterprise. But this is not something that comes without a price. While the devices themselves are

not be prohibitively expensive, the bandwidth requirements have a high price.

Video conferencing solution providers such as RADVISION invest a lot of money in testing for industry

events, such as the IMTC’s SuperOp and the IMS Forum’s PlugFest. But how will YOU - as a consumer,user, system administrator, or an IT manager - know how well prepared YOUR enterprise

infrastructure is for video conferencing?

Example for the effects of bad network conditions on video conferencing

Up until now there was really no way to find out. You could read up on video, try to consult system

integrators about network requirements, or even install a video conferencing system and do some kindof trial. All of these though would amount to nothing, as they cannot substitute for the REAL

thing: testing a LIVE video conferencing system in a LIVE enterprise network.

Too often customer support is called to solve a problem on a customer site, the typical root cause of 

which is mainly infrastructure, or the way the infrastructure works with video conferencing. These

cases would probably fit best an article on “How (not) to deploy video conferencing in the

enterprise.”

Many organizations “jump” from having almost no VoIP communications at all to video conferencing;

Page 22: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 22/39

eBook 

www.VideoOverEnterprise.com December 2008 | 21

and some upgrade their voice conferencing systems to video. Still, the difference in bandwidth

requirement, in tolerance to errors, and in the user experience is quite extreme.

It is senseless that system integrators, IT managers, and service providers can’t test their

infrastructure prior to deployment. Why do they have to wait until they have installed a system to

know if their infrastructure is capable of running it? Simple questions like “how do the conditions of my network affect video quality?”, “is my network ready to provide video services?” or “what may be

the source for video problems?” remain unanswered until the “experts” arrive on site, and valuable

time (and money) is wasted.

Well, all of this is changing with RADVISION’s eVident . eVident is a software testing solution which

you can use during the various stages of deployment, even before you begin looking for a video

conferencing solution or months after you implemented such a system. It allows users to test the

network’s readiness for voice and video over IP, test network configurations, emulate network

topologies, prevent problems and even offer optimal user experience to end-users.

An example of eVident’s deployment in a distributed conferencing solution Imagine that your enterprise has many branches, connected to one another in some infrastructure. It

would be great if you could test the connectivity using REAL video and analyze how well it performs.

Or, think of another example - a CEO who has a 4pm conference call with some analysts… its 3:30pm

now. Is there a way for him to test the connection ahead of time and verify that everything is ready?!

Another important issue is testing video quality. Up until now, video quality has remained something

that only experts understood, even though anyone faced with a video conference will have some

notion of its perceived quality. Objective measures exist, but they are very hard to understand and

have limited correlation to human perception. This situation has caused video quality to be something

no one mentions when discussing network analysis or video conferencing systems.

RADVISION’s Elie Cohen has years of experience with testing and analysis tools. In a recent

whitepaper he discusses the growing need for video quality testing. Combinations of objective and

Page 23: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 23/39

eBook 

www.VideoOverEnterprise.com December 2008 | 22

subjective testing, Elie states that it is the only way to achieve network performance optimization for

video deployments. Elie explains that the integrated approach means monitoring quality using

multiple calls simultaneously and indentifying problems early in the development process, thus

ensuring a high quality user experience.

Therefore, eVident’s voice and video measurement module implement the latest ITU-T standards, butwas calibrated by a subjective global “human eye” video quality survey. This was performed by

RADVISION and showed that the highest correlation was between test results and individual

perception.

Example of similar video streams and their score according to eVident eVident provides voice and video quality measures that anyone can read. This means that you will not

only receive notifications on whether the video is “good” or “bad”, but also a numeric value which

strongly correlates to what you or other end-users will think of the video. On top of that, eVident

implements different network metrics (such as: jitter, delay, packet loss, throughout utilization) in

order to better configure the network for voice and video conferencing.

One may think that a video conferencing system vendor such as RADVISION is “shooting itself in thefoot” by releasing such an analysis tool. However, only by educating the customer, only by giving him

the means to prepare his infrastructure better, and only by cooperating with the customer to provide

the desired user experience will video conferencing be able to truly provide the best means of 

communication.

Page 24: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 24/39

eBook 

www.VideoOverEnterprise.com December 2008 | 23

Advanced TopicsVisual Artifacts in Video over IP

One of the biggest obstacles of the video conferencing industry has long been the user experience.

Early video conferencing systems suffered from poor quality video, low fidelity audio, as well as great

difficulties in establishing and maintaining the connection for the conference duration. Most of these

issues were solved with advances in processor speed, audio and video coding algorithms and network

infrastructure improvement. But even today’s video conferencing experience - with high definition

video, wide-band audio and always-on networks - is not flawless, and the main Achilles heel is, as

always, the network.

The Achilles heel of High Definition - available bandwidth

This is true for video over IP in general - IPTV, video streaming, web casting, you name it. Whether

it’s the one the network is connected to at the office, home or on a mobile handset - bandwidth is

expensive, and therefore bandwidth is limited. Also, transmitting video at reasonable bit rates over

the bandwidth is not trivial and the affect the bandwidth has on visual quality is significant.

Page 25: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 25/39

eBook 

www.VideoOverEnterprise.com December 2008 | 24

Talking heads layout

It can be said that video conferencing is much “easier” in terms of content complexity, than the other

video over IP domains, usually featuring a bunch of “Talking Heads” (also known as CP). Still, as can

be seen in the table below, even at 480p, an endpoint requires around 1 Mbps for good visual quality,

and almost twice at 720p (HD).

A 1Mbps network connection is not a problem in a modern enterprise, but if video conferencing is

deployed all over the organization (as it should be), very soon the existing infrastructure would

become a bottleneck and bandwidth would drop, causing an array of nasty artifacts. Those

annoyances make your video terribly unpleasant. And while other aspects, such as video codec

features, scene type and source type, also influence the visual quality, it seems that network related

artifacts are the most frequent and most annoying.

Insufficient bandwidth will result in packet loss, which leads to lousy video. There are basically two

ways for an endpoint to deal with that - reduce the bit rate and/or increase the compression.

Reducing the bit rate causes a drop in visual quality (as can be seen above). Modern endpoints reduce

the resolution (picture size) together with the bit rate, but still, the experience suffers. Higher

Page 26: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 26/39

eBook 

www.VideoOverEnterprise.com December 2008 | 25

compression rates decrease the visual quality even further.

And so we are left with the following seven deadly sins - I mean artifacts - of video over IP:

The Seven Deadly Sins

1. Packet Loss

If packets are missing, whole areas in the video frame are displayed wrong. This causes ugly artifacts

to appear in various ways, all of them very unpleasant

Packet loss in a multipoint video conference.

Page 27: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 27/39

eBook 

www.VideoOverEnterprise.com December 2008 | 26

2. Trails

These are vertical lines or colored areas, which usually trail an object while it’s moving. This usually

happens when the bandwidth is insufficient, as movement requires more bits.

Left: A scene featuring trails on the person on the left. Right: zoom in on the trails.

3. Blockiness

Blockiness is usually visible on moving objects and backgrounds (walls, furniture). This is caused by a

high compression rate.

Left: original Right: blockiness effect

Page 28: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 28/39

eBook 

www.VideoOverEnterprise.com December 2008 | 27

4. Posterization

Posterization is the loss of color depth. This means that background and other even color spaces look

blurred and lose the sharp transiency between them. Again, this is caused by a high compression rate.

Left: source Right: posterization effect

5. Noise

Noise is a general name for any “weird” looking squares and spots in the video. These are usually

caused by packet loss or erroneous packets.

Random noisy artifacts on video

Page 29: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 29/39

eBook 

www.VideoOverEnterprise.com December 2008 | 28

6. Mosquitoes (Gibbs effect)

Mosquitoes, or in their formal name “Gibbs Effect”, are dots in various level of intensity which

surround edges. This is caused by too high of a compression rate.

Left: visible mosquitoes on the face. Right: zoom in on the face.

7. Scaling

As endpoints lower the resolution when bit rates drop, the picture on the other end is smaller and has

to be scaled up to be displayed on a large screen. Scaling up a low resolution picture is very hard, and

often the visual quality suffers.

Left: qCIF image (source). Right: Scaled up image.

Page 30: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 30/39

eBook 

www.VideoOverEnterprise.com December 2008 | 29

When it comes to visual quality, everyone is an expert. Whether you’re watching a video streamed

over the internet, attending a video conference with peers around the world or watching the news on

your mobile handset - you don’t want anything interfering with your experience, and definitely not

those pesky artifacts.

There are ways to remove, or at least reduce, those annoyances. Those methods mostly involve fancy

post-processing algorithms, but this, I fear, is a matter for a different book.

Codec Manipulation in Visual Communication

Not many people know that H.323, the umbrella under which the ITU (International

Telecommunication Union) defined the protocols for the transmission of unified communication over

packet networks (back when it was simply called “audio-visual communication”), was conceived in the

good old ISDN days.

Nowadays, H.323 is mainly used for video conferencing over IP networks which introduce new

challenges that were not present before. One major challenge is sending media that requires high

bandwidth (especially since the mighty HD became a reality) over a packet switch network with

variable bandwidth, variable packet delay (jitter) and packet loss. Another challenge is the

computational complexity of encoding and decoding the transmitted bit stream. The more complex

the video standard, the more energy (computational power, time, memory) it requires from both

sides.

These challenges have been occupying the visual communication market for a long time and special

mechanisms have been developed to try and deal with these problems. On the one hand,infrastructure is frequently becoming better, both in terms of bandwidth and quality of service (QoS)

and also in terms of the end-equipment that is used in unified communication deployments

(particularly in large enterprises). On the other hand, the demand for this infrastructure is rapidly

growing at a very fast pace and therefore bandwidth available for unified communications is still a

serious problem. The endpoints that were bought last year already struggle to support the current

capabilities of new endpoints.

This infrastructure problem is similar to that of an assembly line, similar to the one depicted by

Charlie Chaplin in “Modern Times“. On the one side, the feeding machine which is operated by a

technician feeds the assembly line with pieces of machinery at an unknown pace. On the other side,

the weak assembly line worker is forced to adapt to the pace of the machine, which has no regard for

the pace of the assembly line.

Even if you are not a certified industrial engineer, you can probably solve the assembly line problem.

All you need to do is allow the line worker to control the speed of the assembly line and the feeding

machine. This can be done by either giving the worker control over the assembly line and machine, or

by regulating some sort of feedback from the worker to those responsible for the assembly line and

machine (for instance, a good old “Slow down, god damn it!”).

Page 31: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 31/39

eBook 

www.VideoOverEnterprise.com December 2008 | 30

It’s true that one can leave the control of the assembly line and feeding machine to others

(technicians, for instance), who would try to adapt to the pace of the worker. However it is clear that

in both cases - the assembly line speed (or bandwidth problem) and the feeding machine’s speed

(processing power problem) - the receiving side (the worker) is the one who can make the best

decision.In video conferencing over IP networks, the bandwidth problem occurs mainly because the available

bandwidth varies during the length of the call as people join in or drop the conference. The

processing power problem is caused by new and more powerful endpoints that send input information

which requires greater processing power from the receiver. In both cases, just like with the assembly

line example, allowing the receiving side to control the characteristics of the input should help solve

the problem efficiently.

Bandwidth estimation in an IP network is prepared by monitoring packet loss indication on the link.

Just as the number of dropped pieces of machinery on the floor of the assembly line would serve as an

indication to a problem with the pace, packets lost (discarded) serve as indication that the available

bandwidth was exceeded.

The standard approach to bandwidth adaptation is that the receiver will send a request to the sender,

asking for a change of bandwidth (known as “flow control message”). Intelligent bandwidth adaptation

algorithms, such as RADVISION’s QualiVision, apply bandwidth estimation and adaptation to optimize

the available bandwidth utilization.

The simple solution to the assembly line worker problem has a flaw

though. When it is implemented in the video conferencing world, as

the bit rate is being reduced the quality of the video stream is also

reduced. Therefore, the system handles the bandwidth adaptation

problem but harms the overall quality.

A better approach is to reduce the resolution (picture size) along with

the bit rate, while maintaining the high quality. LifeSize endpoints,

for example, change the resolution automatically as a result of flow control messages. This is very

beneficial from an endpoint point of view, but causes more instability on a system level - the receiver

no longer is in control over the process.

In the past few years, the problem of giving the receiver - and not the sender - control over the

parameters of the video sent to it has been the focus of many in the video conferencing business. An

ITU study group (SG16) led by RADVISION has been designing such a mechanism over the last two

years.The proposal is to add a “Video Sub-Mode Control” (see original draft here - pdf ) to H.241, the ITU

recommendation that deals with “video procedures and control signals”, in order for better control to

be achieved during a call by the receiver of a video stream over parameters such as frame rate (Macro

Block rate, to be more accurate), resolution (picture size), frame aspect ratio, etc. All of these can

help in both optimizing the use of a given bandwidth and the use of processing power.

Due to the urgency to find a solution to this problem, all leading vendors generally agreed to the

proposal, which was consented in this month’s Geneva meeting. Now all that remains is to deploy this

Page 32: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 32/39

eBook 

www.VideoOverEnterprise.com December 2008 | 31

mechanism and make sure that in these “modern times” everyone will be able to enjoy high quality

unified communications, as they expect and deserve.

Scalable Video Coding and the Future of Video Conferencing

In Short

Scalable Video Coding (SVC) is an interesting technology. It definitely shows the potential that still

lays in H.264 tools for video applications such as video conferencing. I believe that the media

attention it is receiving will improve the video conferencing market, as it will push vendors to

introduce more tools that will improve the overall quality of experience.

The long answer

SVC, the latest extension to the popular H.264 video coding standard, has been getting a lot of media

attention, but Scalable Coding is not a new concept. The idea of sending a single bit stream which

would fit different receiver capabilities (in terms of frame size, frame rate, bandwidth and

computational complexity) has been charming video coding researchers and video application

manufacturers as wired and wireless networks evolved over the past 15 years.

As video is sent to several receivers with their own processing capabilities, several problems arise for

the aggregator of the content (the MCU, video conferencing applications, the streaming server, a

streaming application). It can settle for the lowest common denominator and ruin the experience for

all, or it can try to fit the stream for each participant separately, spending lots of resources and

bandwidth.

SVC attempts to solve this issue by offering a single stream that is built like an onion in which each

Page 33: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 33/39

eBook 

www.VideoOverEnterprise.com December 2008 | 32

participant can peel the layers of the stream up to the point where they feel comfortable with the

result (meaning, it can process the layers that are left). In this way, the “base layer” of an SVC

stream, the core of the onion, can include support for the lowest resolution (CIF, for instance), and

the outer layers will include information that allows to scale-up the resolution gradually too, for

instance, 4CIF (1

st

layer), 720p (2

nd

layer) and 1080p (3

rd

layer).

720p @ 30fps

480p @ 30fps

CIF @ 30fps

qCIF @ 15fps

SVC

Encoder

Source: 720p @ 30fps

AVC

Decoder

SVC

Decoder

SVC

Decoder

SVC

Decoder

 Example: SVC encoder with multiple receivers.

Any network component can then choose to process any set of layers, yielding the different

resolution(s) it chooses. In a similar way, layers can increase the frame rate (the number of frames in

the stream), the bit rate, or the quality (the base layer has low quality; higher layers improve the

quality gradually).

All major video coding standards since 1994 have included tools for scalable coding (MPEG-2, H.263

V2. MPEG-4). It doesn’t seem like that long ago when there was big hype around MPEG-4’s scalable

video coding tools which offered a brand new disruptive alternative to the traditional coding schemes

of the time (see part 8 of this interesting pdf: MPEG-4 overview).

Not all of these tools were accepted by the video applications market, even though the standards

themselves were, mainly due to the tremendous additional cost in terms of bit rate and computation.Although, it was appealing to send just one stream instead of multiple streams from a streaming

server to different clients, the overall bit rate of that one stream was close to the aggregate total of 

the different streams complexity and cost. Therefore the solution didn’t stick.

Page 34: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 34/39

eBook 

www.VideoOverEnterprise.com December 2008 | 33

H.264 SVC

Scalable Video Coding (SVC), the extension of the H.264 standard, has been developed since October

2003 by the Moving Picture Experts Group (MPEG) at ISO/IEC. In January 2005 MPEG and the Video

Coding Experts Group (VCEG) at ITU-T agreed to standardize SVC as an amendment to the H.264standard. In July 2007, this amendment got its final approval.

The scalability extension of H.264 offers spatial scalability (frame size adaption), temporal scalability

(frame rate adaption) and fidelity scalability (quality adaption). It also provides a great boost in error

resiliency and concealment, which helps prevent errors in the bit stream and recover from them

gracefully.

Many applications, such as video streaming, surveillance, broadcast and storage may potentially

decide to adopt SVC. For video conferencing SVC offers two potential benefits:

Compatibility among different endpoints, from desktop to conference room, as the variety of their

capabilities is a great challenge to current MCUs.

Greater error resiliency as modern networks still introduce many artifacts to the video which hurt the

quality of experience tremendously.

The main question here is whether or not these benefits will drive SVC into the video conferencing

market?

Adaption to Different Endpoint Capabilities

As a general idea, adaption to different endpoint capabilities does sound great. The main problem is

interoperability. If your network is, as RADVISION believes, to be the Babel Fish of all video

conferencing endpoints, encompassing a full range of products from the mobile handset through the

desktop and up to HD video conferencing and Telepresence, then the range of video resolutions,

frame rates and bit rates that you have to support makes the use of SVC very complicated, especially

if you also need to support non-SVC (legacy) endpoints.

Page 35: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 35/39

eBook 

www.VideoOverEnterprise.com December 2008 | 34

That is because in SVC, the world is divided into layers. If you want your stream to include both CIF

and 720p, you need two layers. If you want other resolutions as well, you need even more layers.

Note: that the combination of resolutions, bit rates, frame rates and their various combinations

becomes quite high and the overhead in bit rate and complexity makes SVC less appealing.

One may argue that we will see hybrids between SVC and AVC (the more common H.264 codingstandard) which will offer gateways to transcode between the SVC world and the AVC world. But then

again, you build a world of isolated islands, which - just like with Telepresence - is something we’ll

have to deal with sooner or later.

SVC for Error Resiliency

The use of SVC or SVC-like techniques to improve error resiliency and error concealment is, IMHO, the

biggest short term benefit to the video conferencing world, out of all the hype concerning this

technology.

Error resiliency schemes and tools already exist in H.264 AVC (pdf), but are mostly not used in thevideo conferencing domain. SVC will assist video conferencing to move forward by giving these tools

the spotlight.

Error concealment in H.264. Source: Signal Processing group, University of Bristol.

With SVC being introduced and companies like Vidyo pushing it hard and marketing their proprietary

error concealment capabilities, the focus of video conferencing vendors will change. More error

resiliency tools, but not necessarily the SVC tools, will be used and that will improve the overall

experience for all.

The value of Scalable Video technologies for improving error resiliency is clear. However, instead of a

dramatic “phase transition” into SVC, the video conferencing market should evolve gradually into

scalable technologies.

Bottom Line

SVC is intriguing but the video conferencing market will not move entirely to it. Instead, it will adopt

ideas and technologies into its fine foundations, making the video conferencing experience better.

Page 36: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 36/39

eBook 

www.VideoOverEnterprise.com December 2008 | 35

About The AuthorSagee Ben-Zedeff has been managing R&D teams, both first-line and second-line,

developing video technologies and video related products for the past decade. His

experience includes research and development of video coding technologies,

implementation of video codecs on various embedded systems, and development of 

complex media processing products for the V²oIP market.

Sagee currently manages the DSP group in RADVISION, responsible for all media

processing capabilities in the Networking Business Unit (NBU) line of products.

Sagee writes "Video Over Enterprise", a RADVISION blog that covers video products andinnovation from an enterprise perspective.

Sagee holds a BSc in Computer Sciences, Statistics and Operations Research and a BA in Managment

and Economics.

Contact Information:

e-mail - [email protected] 

blog - http://www.VideoOverEnterprise.com  

RADVISION’s Video Offering

RADVISION’s SCOPIA offering is the industry’s most comprehensive, robust video platform that delivers

the scalability and seamless device support enterprises need to leverage and protect current

standards-based conferencing investments. As high definition (HD) endpoints bring higher and higher

video quality to traditional room based video conferencing systems, and Unified Communications and

collaboration solutions extend video to the desktop and mobile arenas, more and more organizations

are turning to RADVISION for the flexibility to cost-effectively adopt emerging HD and UnifiedCommunications technologies.

The SCOPIA platform is a powerful combination of hardware and software that supports media

processing for advanced room system devices and delivers high scalability and distributed processing

for desktops and mobile deployments.

Page 37: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 37/39

eBook 

www.VideoOverEnterprise.com December 2008 | 36

SCOPIA Unified Communications Video Infrastructure

MCUs

Reliable and highly scalable visual communication infrastructure solutions for enterprise and serviceprovider environments, RADVISION’s SCOPIA Conferencing Platforms offer the industry’s most

technologically advanced and easy-to-use multipoint infrastructure for real-time conferencing over

any network, protocol and device. Easy to use plug and play functionality minimizes initial setup time,

and offers unmatched flexibility. High Definition (HD) is standard on each system, enabling HD at

720p, H.264 with up to 30 frames per second of perfect quality video.

Desktop Video Conferencing

With RADVISION’s PC based SCOPIA Desktop, you don’t need to go to “the conference room” to have a

conference. SCOPIA Desktop easily extends a room system conferencing application to remote and

desktop users for voice, video and data communications. Take conferencing “where you go” – instead

of being told “where to go!” SCOPIA Desktop is designed to meet the demands of high performance

video conferencing with a standard PC and Internet connection. It includes the latest in video

technology providing HD H.264 for viewing both meeting participants and data collaboration. Its audio

system provides echo cancellation, background noise suppression, and is highly resilient to network

errors common on the Internet.

SCOPIA Desktop is a simple web browser plug-in that is centrally managed and deployed without

complex licensing fees or installation issues. Simply click on a link and in moments you are ready to

go. Include tele-workers in meetings, participate in video conferences from the road, collaborate with

partners and suppliers and seamlessly connect through firewalls.

Gateways

SCOPIA Gateways provide seamless connectivity between different networks and standards to deliver

feature-rich, reliable, multimedia conferencing and communications. The Gateways are ideal for

connecting IP video conferencing networks with ISDN endpoints and networks to fully utilize existing

video conferencing infrastructure investments.

Page 38: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 38/39

eBook 

www.VideoOverEnterprise.com December 2008 | 37

Video Network Management

iVIEW Suite provides a comprehensive management solution for voice and video collaborative

communications. Efficiently manage and monitor a video network to ensure efficient bandwidth

utilization, easy meeting scheduling, management and control for an optimal, high quality video

communications experience. iVIEW delivers full gatekeeper functionality, complementing RADVISION’s

SCOPIA video network infrastructure and MCUs.

Firewall Traversal

SCOPIA PathFinder Firewall Traversal is a complete firewall and NAT solution enabling secure

connectivity between enterprise networks and remote sites. SCOPIA PathFinder maintains the security

and advantages of firewall and NAT over heterogeneous video networks and allows seamless

integration with existing video endpoints and infrastructure components.

Gatekeepers

RADVISION's high-performance, standard-compliant H.323 ECS (Enhanced Communication Server)

Gatekeeper provides the most intelligent, advanced backbone management system for IP telephony

and multimedia communication networks. ECS provides gatekeeper functionality and everything

required to simply and easily define, control and manage voice, video and data traffic over IP

networks - no matter how large or complex. ECS ensures optimal bandwidth utilization to deliver

carrier-grade, best-quality call completion and video collaborative communications over any network

and any protocol.

Unified Communications Integration

RADVISION’s SCOPIA maximizes a Unified Communications real-time collaboration investment by

turning it into a complete conferencing solution. The SCOPIA Conferencing Platform allows users to

create and initiate multiparty audio and video conferences directly from within industry leading

Unified Communications applications and extend those conferences to devices such as standards-based

video conferencing systems, 3G videophones or virtually any telephone available today.

Media Servers (Interactive Video Platforms)

The SCOPIA Interactive Video Platform (IVP) is a powerful general purpose media server with a flexiblehigh-level API and Service Creation Environment for generating a wide range of video services. With

the SCOPIA IVP, service providers, enterprises and developers can now easily create and reliably

deploy interactive video services seamlessly integrated with existing networks. These real-time,

video-based services offer a high revenue margin complement to traditional voice and data services

for true added value.

Page 39: Video Conferencing eBook

8/8/2019 Video Conferencing eBook

http://slidepdf.com/reader/full/video-conferencing-ebook 39/39

About RADVISIONRADVISION (NASDAQ: RVSN) is the industry’s leading provider of market-proven products andtechnologies for unified visual communications over IP and 3G networks. With its complete set of standards based video networking infrastructure and developer toolkits for voice, video, data andwireless communications, RADVISION is driving the unified communications evolution by combining the

power of video, voice, data and wireless – for high definition video conferencing systems, innovativeconverged mobile services, and highly scalable video-enabled desktop platforms on IP, 3G andemerging next generation networks. For more information about RADVISION, visitwww.radvision.com. 

USA/AmericasT +1 201 689 6300F +1 201 689 6301 [email protected] 

APACT +852 3472 4388F +852 2801 4071

[email protected] 

EMEAT +44 (0) 20 8757 8817F +44 (0) 20 8757 8818

[email protected]