Application Delivery Networks - Enabling Video Ready Networks


Published on

  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Application Delivery Networks - Enabling Video Ready Networks

  1. 1. White Paper Application Delivery Networks - Enabling Video Ready Networks >
  2. 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? 1 < >
  3. 3. Video Ready Networks 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 2 < >
  4. 4. Video Ready Networks 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 3 < >
  5. 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. 4 < >
  6. 6. Video Ready Networks 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: 5 < >
  7. 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 capacity planning. 6 < >
  8. 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. 7 < >
  9. 9. Video Ready Networks 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 8 < >
  10. 10. Video Ready Networks 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 9 < >
  11. 11. Video Ready Networks 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. 10 < >
  12. 12. Video Ready Networks 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: 11 < >
  13. 13. Video Ready Networks -> 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. 12 < >
  14. 14. Video Ready Networks 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 13 < >
  15. 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 14 < >
  16. 16. Video Ready Networks 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? 15 < >
  17. 17. 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.