2. Video Ready Networks
Application Delivery Networks - Enabling Video Ready Networks
In an uncertain economy, controlling travel costs is critical to enterprise
profitability. At the same time, employees are expected to produce ever-
higher results. IT managers worldwide are now forced to reduce budgets yet
deliver the same or better network and application user experience. Doing
more with less is the “operative” term.
Video Conferencing is High ROI?
Reducing travel can save significant costs. Simply moving a meeting to a
video conference can save thousands of dollars in reduced airfare, hotel and
related travel costs. Some companies report saving as much as $120,000
USD on one group meeting alone just by eliminating travels and using
remote communications. Other travel expenses, plus lost time due to travel,
makes the savings much greater.
Productivity is a key requirement for video conferencing. Managers can ill
afford to be away from the office all the time, and video conferencing allows
them to reduce travel times and use this time instead more productively. A
network running high performance video conferencing enables improved
inter-office collaboration and productivity while also allowing the enterprise
another low cost alternative to interfacing with customers, suppliers
and partners.
The Challenge of Video Conferencing Implementation
Despite the clear benefits, the cost of running and maintaining a dedicated
video conferencing connection can be prohibitive, particularly in a multi-
office or multi-region scenario. Moving to a converged network offers
clear costs savings; yet complicates the ability to obtain high and reliable
quality video connectivity over IP. Other applications running on the network
compete for scarce bandwidth, often squeezing out sensitive real-time
applications like video conferencing or VoIP.
Today, more and more employees are working out of the office and require
the ability to stay connected and to collaborate remotely with colleagues.
Productivity is a key cost consideration; yet most video conferencing
deployments don’t cover all offices and are usually limited to only the major
branch or headquarter locations. What about new and smaller remote
offices: SOHOs and remote tele-workers?
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Video Conferencing Options
Many enterprises have deployed large telepresence deployments for regular
large group meetings. These are often quite costly deployments where
the entire facility is outfitted for the conferencing system including audio,
screens, lighting, etc. Typically 5-8 Mbps of bandwidth are required to run
each high definition telepresence conversation.
Enterprises have also typically deployed smaller conference terminals for
smaller group meetings that usually include a set-top box for the screen.
These come in a variety of sizes and configurations and generally require
between 1 to 5 Mbps of bandwidth to be functional.
An increasing number of enterprises are looking to take advantage of
individual desktop video conferencing which can be deployed directly at
the user’s workstation for individual one-to-one or one-to-many video
conferences. These are often deployed for executives and senior managers
and in two types: terminal based or software based (using webcam). The
software version is more cost effective and provides an opportunity for the
enterprise to deploy a low cost video conferencing solution for all employees,
as well as remote users.
Despite the IT department sanctioned modes of video conferencing, there has
also been a marked increase in non-sanctioned, “unmanaged video” through
applications like Skype, Yahoo Messenger, and MSN. Anyone with a webcam
can use this feed. Most of these applications, however, are not supported by
the IT department. If left un-controlled, such unmanaged video traffic can
impact other video conferencing and real-time applications.
The Video Conference Performance Problem
Video conferencing is becoming widely deployed across enterprises today as
both a means to reduce travel costs and to increase workplace collaboration
and communication.
Unfortunately, video conferencing quality is not always as good as expected,
nor is it predictable; often disrupting otherwise efficient virtual meetings.
In an unmanaged converged network, all application traffic competes
with each other to secure limited WAN and Internet bandwidth. The
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communication between video conferencing terminals in the branch and
the MCU in the headquarters is typically compromised by competing
enterprise application traffic and back-hauled Internet traffic. Web surfing,
file transfers, email, backups and particularly unmanaged video traffic
frequently disrupt video conferencing performance.
Mobile Remote
Video Access
Conf
Headquarters
Business Web & SaaS
Border
MCU Controller
Internet
C
CONGESTION
Video
C
CONGESTION
P2P & Recreational
Conf
WAN
Unmanaged
Video
Users C
CONGESTION
Branch
Data Center C
CONGESTION
ERP Branch
Video Conf Users
Email File/Backup Enterprise
Apps
Video Conf Users
Figure 1. The Challenge of Video Conferencing Quality - Other Applications
Without control, the result is non-guaranteed video conferencing quality and
user experience. Broken images and garbled audio quality adversely affect
meeting productivity making it sometimes impossible to communicate.
Figure 2. Recreational Traffic Disrupts Video Frame Quality
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5. Video Ready Networks
IT organizations are trying to understand how they can take migrate to
lower cost converged networks for data and real-time voice and video traffic
without sacrificing the performance and reliability of critical applications.
This paper focuses on answering this challenge and explaining how
enterprises can move to a converged network while improving application
performance and ensuring the high quality and availability of video
conferencing. Regardless of the existing vendor video conferencing system
deployed, there are certain common technologies that are required to enable
a video ready network across the distributed enterprise.
Preparing the Network to be Ready for Video Conferencing
The traditional network infrastructure of switches and routers lacks the
required intelligence and control to fully improve the video conferencing
experience. To be ready for video, a network must first have the visibility to
discover and see all application traffic, as well as the ability to:
-> measure the quality of video and audio in real-time
-> prioritize and shape all traffic to reduce the data sent over the WAN link to fully
mitigate WAN congestion
-> isolate problems when they occur and quickly recover performance
Together these features enable the network to become more intelligent;
a key requirement to supporting high quality video conferencing over IP
networks. Acceleration reduces the data on the WAN link for web, bulk data
and video streaming application resulting in an improved user experience.
Real-time monitoring, centralized reporting and proactive management help
the IT manager track and control video conference performance across the
distributed enterprise.
At same time, real-time monitoring, centralized reporting and proactive
management help the IT manager track and control video conference
performance effectively.
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Enabling Video Ready Networks
Figure 3. Technology Pillars That Enable Video Ready Networks
Traditional packet layer connectivity integrated with native application
intelligence and performance control is the technology underpinning of an
Application Delivery Network.
Intelligence and performance control in enterprise networks are the key
factors to successfully deploying high quality and low cost video conferencing
systems. Unfortunately, these attributes are not included in most video
conferencing facilities today. Blue Coat’s Application Delivery Network
infrastructure provides a simple, powerful and comprehensive set of
functionality that ensures an enterprise maximizes their investment in video
conferencing and guarantee high quality and performance without adding
additional expensive bandwidth.
Ensuring High Quality Video Conferencing Throughout the Whole
Deployment Cycle
Taking an end-to-end approach to managing video conferencing is critical
to ensuring high quality. It’s not enough to simply be able to see the traffic,
the IT manager needs to be able to monitor application performance pro-
actively, optimize the WAN efficiently, and resolve problems quickly to ensure
a tight SLA and a quality user experience. With UDP applications, any lost
packets or jitter/delay can be detrimental to the user experience.
End-to-end management of video conferencing applications enables the
enterprise total control over the applications running on the network and
video conferencing performance in particular. End-to-end management and
maintaining a strict enterprise-wide SLA requires successful:
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7. Video Ready Networks
-> Planning
-> Deployment
-> SLA monitoring
-> Acceleration & WAN Optimization
-> Operations
-> Trouble-shooting
Figure 4. Ready All Deployment Phases
WAN Bandwidth Requirements - Video Conferencing and Data
Video conferencing quality and data application performance are not typically
an issue within a corporate LAN, as bandwidth tends to be plentiful. The
most significant point of congestion and potential compromise to video
quality is at the LAN/WAN boundary. Here video and data traffic must be
carefully controlled as it leaves the LAN and transitions to a WAN link that is
far more bandwidth constrained.
Determining how much WAN bandwidth is needed requires first clarifying
the number of concurrent video conferences expected to be supported. The
codec selected will also influence bandwidth requirements.
Application visibility tracks and advises on how much bandwidth is being
used by a video conferencing and data application, and enabling the
enterprise to segregate essential real-time traffic from non-essential
application traffic such as email or certain types of file transfers. With
detailed information on current bandwidth usage and projected video
traffic, the enterprise is better prepared to conduct accurate WAN
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8. Video Ready Networks
Bandwidth Scaling is Not Always the Answer
At times, it may be required to increase the size of the WAN link to
support video conferencing traffic; however, it is not advisable to increase
bandwidth without first adopting a video conferencing application delivery
strategy. Why? Because IP allows users to consume all available bandwidth
regardless of the link speed; much like traffic tends to rapidly fill new lanes
on a freeway. Simply adding more bandwidth without proper bandwidth
management and control may only result in adding more traffic and
congestion rather than improving the quality of the video conferencing
experience. Before buying more expensive bandwidth, leased lines or
MPLS links, it’s recommended to first undergo an network assessment to
determine what applications are running on the WAN and whether more
bandwidth will actually help or hurt the video conferencing experience.
Deploying a Video Ready Network
Before deploy video conferencing, adequate visibility and control are required
to ensure maximum performance and value from existing WAN links. The
preferred starting point is to understand exactly how WAN bandwidth is
being consumed. Most network managers do not have full visibility into
their WAN traffic and are surprised to learn that over 50% of bandwidth
is often consumed by recreational applications such as P2P, web surfing,
social networking, IM or video downloads. Indeed, a lack of application-
layer visibility is often a first impediment that makes it difficult to prepare a
network to be video ready.
Deep Visibility & WAN Application Traffic
All routers and switches have basic layer 3 visibility. E.g. 10Mbps on
your WAN link. Some routers and layer 4 devices have NetFlow or layer 4
visibility that can recognize port-based applications. E.g. TCP80 – HTTP,
TCP25/110-Email.
Lots of applications use dynamic ports, such as P2P and video conferencing
that layer 4 or NetFlow visibility cannot identify. What’s more, more
applications are using TCP 80. Without the ability to distinguish between
SAP on TCP 80, web surfing on TCP 80 and recreational online video on TCP
80, existing network solutions cannot separate mission critical traffic from
non-critical traffic.
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Indeed, 80% of visibility solutions on the market today stop at layer 4.
Enterprise IT managers need deeper visibility to find out all the sub-
applications and applications using dynamic ports.
The Blue Coat PacketShaper, the central enabling platform for video ready
network, provides Layer 7+ visibility. It discovers all application traffic on
the network automatically (over 650 applications), as well as localized and
customized applications. The user-defined application feature helps IT
extend visibility to include and recognize self-developed applications that are
unique to each enterprise.
Layer 7 Plus visibility discovers all application level traffic running across
WAN links, clearly distinguishing between critical business applications,
email, FTP file transfers, Web surfing, recreational applications, malicious
traffic, and more. The PacketShaper goes beyond layer 7 visibility to identify
sub-applications and even applications that are using the same or dynamic
TCP/UDP ports. Further, it supports granular application classifications and
detailed metrics on the user experience.
Application control is only as good as the visibility into the applications
running on the network. Blue Coat Layer 7+ visibility provides the most
powerful capability to control all traffic on the network including video
conferencing. Blue Coat gives you the ability to immediately control or
block this traffic, individually or as a class, as it meets the particular
network use policies of the enterprise; an essential step toward effective
control for video conferencing.
Blue Coat
Figure 5. Layer 7 Plus for Deep Application Visibility
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Meeting the Performance Challenge
There are three critical performance issues that need to be considered prior
to video conferencing deployment:
1 Latency – the end-to-end delay in delivering the video/voice stream from the
presenter to the audience
2 Jitter – the unpredictable, variable delays in the delivery of each video
conferencing packet
3 Packet loss – the dropping of individual packets caused by network congestion
Each of these three issues can cause significant degradation in conferencing
quality and overall system reliability.
Latency
Video conferencing includes 2 typical modes: one-way presentation and
two-way interactive communication. Two-way interactive communication
is sensitive to delays in the network. Although conferencing quality is still
“acceptable” when delay reaches 300ms, users will feel obvious lag, and
they have to use video conferencing as a walkie-talkie to avoid confliction. In
addition to the voice stream itself, latency must also be addressed with other
video conferencing protocols (SIP, H.323, etc.) that handle the call control
functions between two systems. In fact, these signaling protocols are often
even more sensitive to delays in the network than video or voice packets.
Jitter
Jitter causes irregularities in the flow and delivery of data. This can be
disruptive to a real-time application like video conferencing. Some video
conferencing vendors have tried to solve this problem by introducing their
own jitter buffers or queues to temporarily store and “smooth out” the
delivery of voice packets. Likewise, routers also offer queuing mechanisms
for the same purpose. Both options, however, can exacerbate the problem
by actually contributing to delays. Even with jitter buffering technology, the
tolerance for video conferencing is 100ms. If jitter causes delays to exceed
this range, especially on a consistent basis, conferencing quality will suffer.
Packet Loss
Because IP is a “best effort” protocol, if left unattended it will always be
subject to unpredictable performance including packet loss. Like jitter
and latency, packet loss can be very disruptive to video conferencing
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performance. Packet loss can become a serious problem at the LAN/WAN
boundary where the smaller pipe results in much greater contention for
bandwidth. Although a packet loss of 1 percent or less is within the bounds of
toll quality video, once packet loss reaches 3 percent or more, the audience
will notice the conversation breaking up. Unless this problem is controlled,
packet loss can ultimately lead to dropped calls and the possibility of video
conferencing system failure.
Intelligent Policy Control - Simply Better
Intelligent policy control is the core of Blue Coat’s Application Delivery
Network infrastructure. Compared to legacy QoS solutions, intelligent policy
control is:
-> Smart – automatically discovers & distinguishes between applications
-> Granular – control per application, per call & per flow
-> Powerful – controls inbound traffic to avoid congestion
-> Simple – facilitates ease-of-use with on box policy manager& centralized
management
Per-flow dynamic control
Although typical routers have some basic QoS features, these static
QoS features are not adequate to meet the demands of dynamic video
conferencing traffic. The most common way routers protect critical
applications is through bandwidth reservation. Dedicated bandwidth is
assigned to particular applications to ensure performance. While this works
for some static applications, video conferencing is highly dynamic and the
number of concurrent media flows is uncertain. How then to ensure enough
bandwidth is reserved?
An Application Delivery Network offers guaranteed video conferencing
application performance over WAN links by employing per-flow control
technologies capable of minimizing IP congestion and avoiding packet loss.
Intelligent policy control provides per-flow dynamic control. Bandwidth is
assigned to video conferencing according to the number of media flows.
Each flow obtains guaranteed bandwidth to ensure video quality without any
bandwidth being wasted. Intelligent policy control converts IP network from
“best effort” to predictable.
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TCP Rate Control
TCP rate control is Blue Coat’s patented technology that shapes application
bandwidth. Most routers use queuing and bucket technologies for bandwidth
shaping. Routers only control the outbound speed to enforce bandwidth
policy. Any additional data will be dropped if the bucket (buffer) is full.
Packet dropping causes the sender to reduce the transmitting speed and re-
transmit to adapt to the bandwidth policy. This only creates more congestion,
packet drops and retransmits in the networks, and the efficiency and quality
of networks actually gets worse. Although routers support traffic shaping,
the router can actually hurt the quality of video conference.
TCP rate control, Blue Coat’s patented technology, shapes application
bandwidth enabling a better video conference quality and improved overall
application experience. By using TCP window technology to control the
sender’s transmit speed directly, all in-coming traffic is controlled, reducing
WAN congestion. This results in no congestion, no packet drop, and not
needing to retransmit. All applications run smoothly reducing delay, jitter
and packet loss by up to 60%
Inbound Rate Control
Maintaining quality for mobile video conferencing is a challenge for most
QoS solutions. All web surfing, remote access and mobile video conferencing
traffic crowds the Internet link on the inbound connection. Traditional QoS
(such as Router QoS) only enforces the point behind Internet link causing
congestion to occurs before the router can shape the traffic. In contrast,
Intelligent Policy Control using TCP rate control alleviates the root cause of
the congestion; the speed of incoming traffic. With an Application Delivery
Network, Blue Coat extends high quality video conferencing to the network
edge (teleworkers) and goes beyond existing QoS solutions.
Adaptive Policy
Intelligent Policy Control has the ability to adjust policy dynamically
according to the underlying traffic conditions.
Example: video conference, SAP and non-critical traffic run on a
16Mbps WAN links. The administrator predefines multiple policies
for different conditions:
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-> When no video conferencing traffic is detected, assign 10Mbps bandwidth to SAP.
-> When video conferencing is running and bandwidth is less than 5Mbps, bandwidth for
SAP is reduced from 10Mbps to 5Mbps automatically.
-> Once video conferencing traffic is greater than 10Mbps, all non-critical applications
are blocked automatically to reserve bandwidth for SAP.
All policy adjustments are dynamic and automatic. Once policy is set, the
network adapts to all traffic conditions in a pre-defined manner, removing
the need for manual intervention.
Figure 6. Video Conferencing Without Policy Control
Figure 7. Video Conferencing With Policy Control
Router QoS & Video Conferencing Performance
As described earlier, router QoS lacks Layer 7 visibility, intelligent control,
inbound rate control and video conferencing metrics.
Using router QoS, the enterprise can’t identify critical applications,
recreational traffic or video traffic. These routers provide limited means
to control different types of traffic and align them fully to the enterprise
business. Routers cannot assign bandwidth dynamically, causing
bandwidth to be wasted. Moreover, routers can’t prevent inbound traffic
congestion from impacting remote video conferencing, so enterprises
cannot extend video conferencing services to small branches and remote
teleworkers. Routers also lack the capability to track user experience and
help IT troubleshoot performance issues pro-actively. Finally, routers
don’t have acceleration features and require the enterprise to scale
additional bandwidth when deploying additional applications; increasing
connectivity costs.
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Acceleration &Compression
Gaining visibility into WAN application traffic and applying Intelligent Policy
Control are two critical steps to ensuring best-in-class application delivery.
A third essential step is to apply compression to specific traffic types. Video
conferencing is compressed by the codec (e.g. H.261, H.263, H.264, G.722,
G.728, G.729) used to deliver video/voice packets across the WAN. Although
additional compression of video/voice traffic is not advisable because it
will compromise conferencing quality, there are opportunities to apply
compression to various data applications such as email, ERP, and various
types of Web traffic that compete for limited bandwidth. This can save
bandwidth and reduce WAN congestion.
Acceleration reduces the data on the WAN link for web, bulk data (file
transfers, email, etc.) and video streaming application resulting in
an improved user experience. The PacketShaper provides real-time
compression to get 2x-4x capacity gain for data applications; thereby
optimizing data transmission. Application Delivery Networks also support a
direct-to-net architecture that removes web surfing and recreational traffic
from expensive WAN links and avoids WAN bandwidth scaling.
Traffic from Branch to HQ
Video Conf Traffic Protected
Enterprise Apps Compressed
Web Surfing Direct to Internet
Figure 8. Acceleration & Optimization Make WAN Traffic More Efficient
Video Conferencing Signaling and Control Protocols
Video conferencing technology relies on H.323 as the primary protocol suite
for media signaling and control. But video conferencing has also started to
use SIP as well. Each of these protocols behaves differently on the network,
but all can be effectively controlled using an Blue Coat Application Delivery
Network infrastructure due to the granularity of application control available.
The MCU & WAN Performance
Most video conferencing systems include an MCU. The location of the MCU
decides the routes of video traffic in the enterprise WAN. The PacketShaper
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15. Video Ready Networks
identifies all the traffic between MCU and video conferencing terminals, and
helps IT organizations design their WAN links connecting the headquarters
and branches according to the real bandwidth required for any particular
video conference.
Interactive Applications
Video conferencing is often used to increase collaboration among employees
and customers. Interactive applications, including whiteboard, collaboration
software and even file sharing, are all becoming key applications for video
conferencing. Bandwidth for interactive applications are more random and
various than video/voice traffic. The PacketShaper detects T.120 and file-
sharing automatically, and provides committed application performance by
assigning bandwidth dynamically, as well as enabling auto-discovery over
650 types of applications.
Monitoring SLAs for Video Conferencing
Performance issues can happen at the worst times (during a meeting
with a customer) and it’s often very difficult to predict. Even with someone
monitoring the health of the entire network 24/7, very often by the time a
problem has become critical, users have already been impacted. Blue Cost’s
real-time monitoring makes it easier to know any performance issues as
soon as they occur. Once the performance issue occurs, an email is sent to
administrators and syslog and SNMP trap is sent to the NMS.
Real-time monitoring works as a ‘meter’ to measure the quality of the
network and the video conference application. It helps the IT department
find potential performance issues proactively, contributing to reduced
helpdesk calls.
Trouble-shooting Performance
The PacketShaper provides the IT department with over 120 measurable
statistics per class along with many powerful diagnostics tools to isolate and
recover performance issues quickly; essential to maintaining an always-on
video ready network.
Video Conference Economics
An Application Delivery Network provides immediate ROI savings and
ensures the enterprise maximizes the investment in video conferencing. With
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the PacketShaper’s ability to control all types of applications, including real-
time UDP applications such as VoIP and video, the enterprise is guaranteed
the high performance and availability needed to ensure video conferencing is
a realistic alternative to in-person meetings.
Blue Coat is the global leader in application delivery networks that enable
enterprises worldwide to effectively align their video, voice and data
applications and network resources with their business priorities while
realizing tangible cost savings. Blue Coat’s value is delivered through a
family of intelligent appliances built with patented software technology
that provides unmatched visibility, acceleration, and security capabilities.
Specifically for video conferencing, Blue Coat addresses chronic congestion,
jitter, and packet loss that afflict video quality at the LAN/WAN boundary.
Blue Coat effectively manages all critical video conferencing protocols and
ensures the highest quality end-to-end communication.
Is your network video ready?
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