application delivery networks - enabling video ready networks

Application Delivery Networks - Enabling Video Ready Networks >

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Video Ready Networks

Application Delivery Networks - Enabling Video Ready NetworksIn 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 ImplementationDespite 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 OptionsMany 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 ProblemVideo 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.

ERPERP

EnterpriseApps

Email File/Backup

UnmanagedVideo

Users

VideoConf

MCUBorder

Controller

MobileVideoConf

RemoteAccess

Business Web & SaaS

P2P & Recreational

Data Center

Headquarters

Users

Branch

Video Conf

Users

Branch

WAN

Internet

Video Conf

CONGESTIONCC

CONGESTIONCC

CONGESTIONCC

CONGESTIONCC

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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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 ConferencingThe 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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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 CycleTaking 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:

Enabling Video Ready Networks

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-> 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

capacity planning.

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Bandwidth Scaling is Not Always the AnswerAt 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 NetworkBefore 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 TrafficAll 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.

Figure 5. Layer 7 Plus for Deep Application Visibility

Blue

Coa

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Meeting the Performance ChallengeThere 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 BetterIntelligent 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 PerformanceAs 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 PerformanceMost 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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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 ApplicationsVideo 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 ConferencingPerformance 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 EconomicsAn 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?

Copyright © 2009 Blue Coat Systems, Inc. All rights reserved worldwide. No part of this document may be reproduced by any means nor translated to any electronic medium without the written consent of Blue Coat Systems, Inc. Specifications are subject to change without notice. Information contained in this document is believed to be accurate and reliable, however, Blue Coat Systems, Inc. assumes no responsibility for its use. Blue Coat, ProxySG, PacketShaper and IntelligenceCenter are registered trademarks of Blue Coat Systems, Inc. in the U.S. and worldwide. All other trademarks mentioned in this document are the property of their respective owners.

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