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Copyright © 2012 Wainhouse Research, LLC Page 1
WHITEPAPER
Multipoint Videoconferencing Goes Virtual
Ira M. Weinstein
June 2012
Sponsored by:
How a next-generation
architecture is changing the
rules of multipoint video
Copyright © 2012 Wainhouse Research, LLC Page 2
Introduction
Today’s business environment is all about doing more with less. Organizations want to process more
transactions and develop more products, all with as few resources as possible. The same rule applies
when organizations make technology investments … they want to get as much utility out of those
investments and resources as possible. This expectation of squeezing every bit of value out of
technology investments has fueled increased interest in server virtualization.
According to Webopedia,” server virtualization is the partitioning of a physical server into smaller virtual
servers.“ Each of the resulting virtual servers are then truly independent, meaning they each run their
own operating system and can even be rebooted individually.
According to a 2011 Symantec survey of 3,700 enterprises around the world, 45% of respondents had
implemented server virtualization1. Given the long list of possible benefits associated with server
virtualization (ability to deploy less hardware, decreased up-front and ongoing cost, improved efficiency,
enhanced scalability, increased reliability and availability, decreased carbon footprint, decreased
management burden, etc.), it’s no wonder that enterprises are embracing server virtualization to such a
large degree.
In many organizations, videoconferencing management has shifted away from the A/V or facilities team
over to the IT department. These IT managers are looking to deploy visual communications in a manner
similar to other applications running on the network, and want to architect their videoconferencing
environments to be cost effective, easy to manage, and easy to scale in response to demand – all of
which can be achieved via virtualization. Traditionally it has not been possible to virtualize certain
elements of the videoconferencing environment – mainly video bridging. Recent technology
developments, however, have made it possible to fit aspects of the videoconferencing ecosystem into a
virtualized resources strategy.
This study outlines the challenges associated with scaling a traditional videoconferencing environment
and highlights a next-generation videoconferencing architecture that is changing many of the rules of
video bridging.
1 https://www4.symantec.com/mktginfo/whitepaper/Virt_and_Evolution_Cloud_Survey_060811.pdf,
http://www.eweek.com/c/a/Midmarket/Adoption-of-Server-Virtualization-Widespread-Symantec-Report-125308/
Copyright © 2012 Wainhouse Research, LLC Page 3
The Fundamentals of Video Bridging
During a video call, each participating location's video and audio signals must be compressed (a.k.a.
encoded) and then transmitted to the remote location where it is decompressed (a.k.a. decoded) and
sent to the local video displays and speakers. This same process happens continuously in both
directions for the duration of the video call.
Figure 1: Encoding and Decoding during a Video Call
The necessary signal compression and decompression (encoding and decoding) is handled by the
videoconferencing system, which might be a dedicated appliance, personal computer, tablet, or
smartphone.
In a traditional videoconferencing environment, video calls involving more than two participants (a.k.a.
multipoint or multiparty calls) require the use of a device called a video bridge or multipoint control unit
(MCU).
Figure 2: A Traditional Multipoint Video Call
During a multipoint call, each participating location sends its video and audio signals to the MCU. The
MCU then decodes the incoming signal, mixes that signal with other incoming video and audio signals in
a process called compositing, and creates (encodes) and sends a new signal composed of all of the other
signals to each participating location. This decoding and re-encoding process is often called transcoding.
Compression Engine
(Encoder)
Decompression Engine
(Decoder)
Decompression Engine
(Decoder)
Compression Engine
(Encoder)
MCU
Copyright © 2012 Wainhouse Research, LLC Page 4
A traditional transcoding MCU must do the work of multiple endpoints simultaneously. For example, if 6
sites are connected to the MCU, the MCU must decode six incoming video and audio signals, perform six
video mixings, and create / encode six different outgoing video signals – all in real time. The need to
handle multiple video encodes and decodes simultaneously makes hosting traditional multipoint video
calls extremely computationally intensive.
Authors Note
Videoconferencing uses lossy compression techniques. This means that each time a video signal is
encoded or decoded, a portion of the original signal is lost. In addition, encoding and decoding
introduces latency (delay), which can impact the ability to interact comfortably during a video call.
In a traditional multipoint video bridging scenario, before a location’s camera signal is viewed by
another participant, it has been encoded by the source video system, decoded by the MCU, mixed /
composited by the MCU, re-encoded by the MCU, and then decoded by the receiving video system.
The use of multiple encodes and decodes has a negative effect on the overall user experience.
The Challenge of Scaling Traditional Video Bridging
The task facing videoconferencing / IT managers is to provide reliable, cost-effective, high quality, and
scalable multipoint videoconferencing for your global organization. From a 10,000 foot view,
enterprises have the following “traditional” options for addressing this requirement:
Option #1 – Hardware Video Bridges Due to the heavy computing demands of traditional video bridging, most video bridging today is handled
by hardware-based MCUs running on custom-built platforms. Unfortunately, there are a number of
disadvantages associated with buying a traditional hardware video bridge including:
Up-Front Cost – for hardware MCUs, list price per port range from $1k to over $10k depending upon
the model, configuration, and video resolution. While this may be suitable for an organization with
a limited number of video systems / users, organizations with thousands of personal video users
expecting to participate in multiparty calls will find this model cost prohibitive.
Operating Cost – hardware video bridges can be
expensive to own and operate. Specific costs include
hardware maintenance, rack space (some MCUs
require 15 or more rack units of space), power
consumption (some MCUs require 1500 watts or
more), and HVAC requirements.
Capacity Planning – hardware video bridge customers must purchase capacity up front as opposed
to purchasing capacity to match demand as it grows. For a service provider, this means an out of
pocket investment vs. an investment that is financed through operating income. For an enterprise
organization, this means additional up-front cost because the MCU must be sized to support the
today and tomorrow’s capacity requirements.
The high per port / connection cost of
traditional hardware video bridges is a
barrier to the widespread adoption of
videoconferencing.
Copyright © 2012 Wainhouse Research, LLC Page 5
Capacity Expansions – expanding a hardware video bridge typically involves a significant cost. In
most cases, expansions of only a few ports are not possible. Instead, customers must purchase a
bank of ports (e.g. 12 or 24) or an entire additional video bridge.
Centralized Architecture – the high cost of even a low capacity hardware video bridge drives many
organizations to centralize their video bridging hardware in a small number of locations. This means
some remote users will be a great distance away from the video bridge, and as a result will
experience audio delays. To avoid this problem, an organization could deploy additional bridges
around the world (a distributed architecture). However, this tends to be cost prohibitive.
Cascading Issues – cascaded meetings include participants connected to two or more video bridges.
The benefits of cascading include expanded capacity beyond that of a single bridge, the ability for
participants to connect to a “local” bridge, and the ability to reduce WAN bandwidth utilization by
sending a single stream between bridges. Unfortunately, cascading traditional video bridges results
in degraded video quality (due to multiple encodes / decodes of each person), increased latency,
and smaller images of many participants. The net is that traditional bridges are not well suited for
cascaded meetings, which eliminates a key benefit of a distributed architecture.
Time to Deploy – deploying a video bridge or adding additional hardware ports may take weeks to
complete. In the traditional group videoconferencing world in which new rooms took weeks to
bring online, this was acceptable. However, in a world in which an organization can bring thousands
of personal video devices (e.g. tablets) online in a matter of hours, this may be a problem.
Virtualization Unfriendly – the use of custom-built hardware means that hardware video bridges
cannot be virtualized.
Option #2 – Software Video Bridges In recent years, a number of software-based video bridges have become available. These bridges
operate in the same way as their hardware-based cousins, but leverage off-the-shelf servers instead of a
custom-built hardware platform.
Software-based MCUs offer several benefits including lower cost per port and lower operating costs
than hardware-based MCUs. However, they also introduce a handful of additional challenges including:
Performance / Capacity Compromise – traditional software MCUs are limited by the computing
power available within the standard Intel hardware platform. As a result, software MCUs typically
force a compromise between performance, feature-set, and capacity. Given the limited capacity of
standard software MCUs, many organizations will need to deploy multiple software MCUs and
servers to meet the demands of their user community.
Cascading Issues – software MCUs tend to have fewer ports than hardware MCU; a situation which
lends itself to cascaded meetings as a means of increasing the maximum number of participants per
meeting. Unfortunately, as described above, cascaded meetings on traditional MCUs are
problematic.
Copyright © 2012 Wainhouse Research, LLC Page 6
Virtualization Unfriendly – Software MCUs are typically installed on dedicated servers. While it may
be possible to run a traditional software MCU on a virtual server, this raises two options:
Option 1 – Dedicate all server resources to the MCU application in order to protect the user
experience. This means that the server cannot host other applications, thereby reducing the
virtualization benefit.
Option 2 – Share server resources across multiple applications to maximize efficiency. Note that
reducing the computing power available to the MCU is likely to impact performance and
capacity significantly, thereby eliminating much of the benefit of a software MCU.
Option #3 – Hosted Video Bridging Service Enterprises may choose to use a videoconferencing bridging service provider. In this scenario, the
service provider purchases one or more video bridges and makes them available to its customers.
There are several key advantages associated with using a video bridging service including the ability to
avoid the up-front cost of an MCU purchase, and the ability to outsource the burden of managing the
MCU to the service provider. In addition, the service provider will be responsible for ensuring that
ample capacity is available to support its customers.
Unfortunately, there are some notable shortcomings associated with this method including:
Usage-Based Cost – hosted bridging service customers trade the up-front cost of an MCU purchase
for either usage-based fees (e.g. $45 / hour / port used), meeting room fees (e.g. $30 / month /
meeting room for up to 5 callers) or monthly fees (e.g. $300 / month / port). Depending on the
usage pattern, this may be more or less expensive than purchasing a hardware or software MCU.
Lack of Flexibility – the use of a single video bridging platform across many customers means that
individual customers cannot configure the bridge to meet their specific needs. Instead, the service
provider defines the bridge settings to address what the service provider believes are the overall
requirements of its customer base.
Option #4 – Resource Rationing One way to deal with the increasing demand for multipoint videoconferencing is to allocate video
bridging resources based on availability. In this scenario, meeting requests are rejected when sufficient
bridging capacity is not available. Although this is a viable option, it is not advisable as rejecting meeting
requests will inhibit user adoption and limit the benefits enjoyed by the host organization. In addition,
this will motivate users to use more accessible communication mediums (e.g. audio conferencing, web
conferencing), even in situations where videoconferencing should be used.
Option #5 – Virtualization This option involves running the video bridging application on standard virtual servers. Key benefits of
this approach for both end-users and service providers include:
Copyright © 2012 Wainhouse Research, LLC Page 7
Low Cost - virtualized servers are less expensive to deploy and operate than dedicated servers and
custom-built hardware
Immediate Scalability – in response to demand, enterprises can “spin-up” virtual servers easily and
quickly, with little or no notice.
Deployment Flexibility – the use of standard virtual servers allows enterprises to deploy the
bridging application on their own server farms or on 3rd party virtual servers. In a matter of hours, a
customer could deploy a globally accessible, distributed bridging architecture without the need for
additional hardware.
IT Friendliness - the above model allows enterprises to treat the videoconferencing bridging
application as they treat all other business applications. This decreases management burden and
allows the VC environment to be supported by general IT resources. This also supports the general
IT trend toward virtualization, and is a giant step toward bringing videoconferencing into the IT
mainstream.
While this may sound like a great concept, the vast majority of videoconferencing bridging solutions
available today do not support the virtualized deployment model.
Summary of Options Options 1 through 3 above suffer from various issues ranging from high up-front cost, limited capacity,
inflexible capacity expansion options, and significant rack space and power requirements to
compromised performance, limited (or no) support for distributed architectures, and ongoing usage-
based fees. As a result, these options are not well suited to meet the large scale bridging requirements
of many enterprises today.
As organizations embrace personal videoconferencing (using UC clients, dedicated PC software, and
mobile devices), the number of users and the number of multipoint participants will increase
dramatically, which makes the problem of scaling video bridging even more acute.
Solution Spotlight – Vidyo
Vidyo, the sponsor of this study, follows a novel approach that supports large scale multipoint video
conferencing without the need for a traditional, transcoding MCU. As a result, the Vidyo solution avoids
many of the issues associated with traditional video bridging.
Vidyo's solution is based on a client / server architecture designed specifically for videoconferencing.
The “secret sauce” within the offering is the use of an intelligent media switching architecture instead of
an MCU-based transcoding architecture.
Copyright © 2012 Wainhouse Research, LLC Page 8
Figure 3: A Typical Vidyo Deployment
Vidyo Endpoints
The first elements within the Vidyo ecosystem are the Vidyo endpoints. Available for meeting rooms,
PCs (Windows, Mac, Linux) and mobile devices (iOS and Android), all of the endpoints leverage the same
software stack.
The Vidyo endpoints use a video compression standard called H.264 Scalable Video Coding (or SVC), and
SVC leverages a concept called video scaling. A video stream is “scalable” if parts of the stream can be
removed in such a way that the resulting stream can still be decoded. Using SVC, the Vidyo endpoints
convert each video stream into several layers.
Vidyo’s use of SVC and the layering methodology provides two key benefits:
1) Exceptionally strong network resiliency, which enables high quality video calling over
inexpensive, lossy IP networks (e.g. the public Internet).
2) The ability to combine the individual layers to create resulting video streams of different
degrees of quality.
Vidyo Architecture
The next part of the Vidyo ecosystem is the VidyoRouter, a software-based solution (delivered running
on a 1 RU appliance or as a virtual appliance running in VMWare and KVM environments) that performs
packet switching of the video signals without transcoding or processing those signals.
Copyright © 2012 Wainhouse Research, LLC Page 9
The VidyoRouter acts as the traffic cop of the environment, providing each endpoint with the
appropriate video layers to match its capabilities (bandwidth, processor power, screen resolution, etc.).
The VidyoRouter supports up to 1440p / 60 fps and up to 100 connections per server.
Figure 4: Vidyo’s H.264 SVC Encoding and Layer Switching Process
Since the video signals are not decoded, composited, or transcoded by the VidyoRouter, latency is
minimized and video quality is maintained throughout the video call. In addition, systems / users
connected to different VidyoRouters can participate in the same call without the quality and latency
issues associated with cascading traditional video bridges.
Unfortunately, traditional videoconferencing endpoints cannot generate the multiple layers necessary
to work natively within the Vidyo architecture. For group video users, the VidyoGateway (also a
software solution) converts these standard H.264 video streams into H.264 SVC streams, allowing the
traditional devices to participate in Vidyo-powered sessions. For desktop users without a Vidyo
endpoint, Vidyo’s “guest linking” capability allows guests to join Vidyo conferences from their PCs via a
hypertext link, similar to the way people join web conferences.
Author’s Note
Several videoconferencing vendors (e.g. Avaya, Polycom) have announced plans to support H.264
SVC in the near future. In addition, various efforts are underway to finalize H.264 SVC signaling and
media standards. This will hopefully result in basic interoperability between at least some SVC
solutions in the near future.
High Resolution - High Frame Ra
Medium Resolution - Medium Frame Rate
Low Resolution - Low Frame Rate
2 Mbps
500 Kbps
3G/4GLow Bandwidth
Medium Resolution - Medium Frame Rate
High Resolution - High Frame Rate
Low Resolution - Low Frame Rate
Source
Base Layer
High Resolution Layer
Base Layer
High Resolution Layer
Base Layer
High Resolution Layer
Base Layer
Copyright © 2012 Wainhouse Research, LLC Page 10
The VidyoPortal manages the deployed VidyoRouters, VidyoGateways, and Vidyo endpoints, allowing
administrators to manage the global Vidyo deployment
from within a single web-based user interface.
Vidyo Goes Virtual
Unlike traditional video bridges which are typically too
processor-dependent to be virtualized efficiently, the
VidyoRouter is available in a virtualization-ready version
(called VidyoRouter Virtual Edition) that can run on
VMWare or KVM virtualized servers in private, public, or hybrid clouds.
End-user customers and service providers can spin up additional VidyoRouter VE instances on demand,
immediately extending the capacity and global reach of the Vidyo deployment. In addition, non-
virtualized and virtualized VidyoRouters can work together to create a hybrid environment.
Vidyo Licensing
Unlike traditional hardware MCUs which require customers to pay up front for all ports, Vidyo operates
on a concurrent connection license model. Each Vidyo concurrent license, dubbed a VidyoLine, supports
one concurrent connection to the VidyoRouter. VidyoLines float among all globally deployed
VidyoRouters, which means that customers need to buy only the licenses to support the maximum
number of simultaneous connections to the VidyoRouter at any point in the day.
Example – Traditional Multipoint Model vs. Vidyo Multipoint Model
The example below highlights the multipoint infrastructure costs for a customer needing to support
multipoint calling for up to 20 sites in each of two locations (e.g. New York and Hong Kong).
Traditional MCU Method Vidyo Multipoint Method
Types of Endpoints Deployed H.323 / SIP Vidyo Room and Personal
Equipment Required – New York 1 x Traditional 20-port MCU 1 x VidyoRouter
Equipment Required – Hong Kong 1 x Traditional 20-port MCU 1 x VidyoRouter
Equipment Required – Any Location 1 None 1 x VidyoPortal
Software Licenses Required 2 None 25 x VidyoLines
Up-Front Cost (US $ - List Price) 3 $250k - $300k ~ $42k2
Annual Recurring Cost 4 ~ $42k (maintenance) ~ $6k (maintenance)
1 Traditional MCU method cost does not include commonly deployed videoconferencing infrastructure items such as gatekeepers, NAT / firewall traversal solutions, and management servers. These items may cost an additional $50k - $150k (depending upon the situation).
2 VidyoLines are only required for Video soft-client endpoints. VidyoRooms and VidyoGateway calls do not require VidyoLines.
3 Includes cost for multipoint infrastructure only. Does not include shipping, installation, configuration, and training costs.
4 Assumes a 15% annual maintenance cost.
2 If the customer wishes to supports point-to-point or multipoint calls between the Vidyo endpoints and legacy
H.323 / SIP video systems, a VidyoGateway (US $6k list price) would be required. Note that additional VidyoLines would not be required.
The Vidyo environment is 1/6th (or less)
of the price of a traditional video
bridging environment, and allows
customers to scale on demand, one
concurrent connection at a time.
Copyright © 2012 Wainhouse Research, LLC Page 11
At a list price of US $42k, the cost for the Vidyo multipoint calling infrastructure is only 16.7% of the cost
of the two traditional video bridges. In fact, the annual maintenance for the two video bridges is
roughly the same as the up-front cost for the entire Vidyo infrastructure deployment!
Note re: Capacity / Expansions
The above Vidyo cost estimate includes 25 concurrent connections around the world (25 on the Hong
Kong VidyoRouter, 25 on the New York VidyoRouter, or any combination in between). Should the
customer require additional simultaneous connections, the cost would be US $950 (one time list price)
per VidyoLine. This licensing model allows the customer to scale on demand, one connection at a time.
For example, for an additional $9,500 (list price for 10 VidyoLines), the customer would be able to host
up to 35 concurrent connections at any given time around the world.
In the traditional MCU world, a capacity expansion of this kind would require the purchase of one or
perhaps even two additional MCUs. Alternatively, if available, the customer could purchase a software
capacity upgrade. In either case, the customer could not upgrade one port at a time, and the upgrade
cost would likely be $100,000 or more.
Alternatively, for organizations seeking to avoid up-front expenses, the Vidyo solution is also available as
a hosted / cloud offering from a wide range of partners around the world. For ~ $30 / month
(depending upon the specific service selected),a user can host unlimited Vidyo-powered meetings
including up to five (5) guests. Non-Vidyo users using H.323 or SIP systems can participate in meetings
for an additional $0.20 / minute. Essentially, this all-OPEX model provides each user with a personal,
hosted video meeting room for no up-front cost.
Conclusion In the past, videoconferencing was available on expensive, hardware-based systems installed within
enterprise meeting rooms only. The high cost and limited number of available meeting rooms served to
limit the number of video endpoints installed throughout the organization, as well as the overall video
call volume. This, in turn, limited the number of multipoint ports / connections required.
Today, videoconferencing is no longer trapped within the board room. Instead, videoconferencing is
now available on user’s desktops and on their mobile devices. This ubiquity is driving the need for
increased multipoint scalability and cost effectiveness.
Enterprise managers are no longer interested in “brute force” solutions to IT challenges. Instead, they
expect solutions to be easy to deploy, manage and scale. Traditional video bridges / MCUs are not well
suited to meet these cost and scalability expectations.
Vidyo, the sponsor of this white paper, offers a next-generation architecture based on intelligent media
switching that eliminates the need for processor-intensive (and expensive) transcoding, increases
flexibility in deployment, supports both virtual and non-virtual environments, allows on-demand
expansions of one connection at a time, and is much less expensive than competing solutions.
Organizations seeking to conduct wide scale multipoint videoconferencing on a global basis should
carefully consider Vidyo.
Copyright © 2012 Wainhouse Research, LLC Page 12
About Wainhouse Research Wainhouse Research, www.wainhouse.com, is an independent market research firm that focuses on
critical issues in the Unified Communications and rich media conferencing fields, including applications
like distance education and e-Learning. The company conducts multi-client and custom research studies,
consults with end users on key implementation issues, publishes white papers and market statistics, and
delivers public and private seminars as well as speaker presentations at industry group meetings.
Wainhouse Research publishes a variety of reports that cover all aspects of rich media conferencing, and
the free newsletter, The Wainhouse Research Bulletin.
About the Author Ira M. Weinstein is a senior analyst and partner at Wainhouse Research and a 20-year veteran of the
conferencing, collaboration, and audio-visual industries. His prior experience includes senior positions
with conferencing and AV vendors, distributors, and resellers. In addition, Ira ran the global
conferencing department for a Fortune 50 investment bank. As the lead analyst of WR’s visual
collaboration team, Ira’s focus includes videoconferencing (mobile, desktop, group, and telepresence /
immersive), streaming / webcasting, and the visual elements of unified communications. Ira holds a B.S.
in Electrical Engineering from Lehigh University and can be reached at [email protected].
About Vidyo (copy provided by Vidyo)
Vidyo, Inc. pioneered Personal Telepresence enabling natural, HD multi-point videoconferences on
tablets and smart phones, PCs and Macs, room systems, gateways that interoperate with H.323 and SIP
endpoints, telepresence solutions and affordable cloud-based broadcast solutions. Learn more at
www.vidyo.com, on the Blog or follow @vidyo on Twitter.