Recently I published a video blog post about RAVE (Remote Audio & Video Extensions), the technology behind SpeedScreen Multimedia Acceleration. RAVE supports high quality playback of media streams that can be decoded by a media player that uses DirectShow or DirectX Media Objects (DMO). A question came in from the field asking how a customer can determine whether SpeedScreen Multimedia Acceleration is functioning. So here are some handy tips for verifying whether RAVE is working or not. In addition, you'll find a helpful troubleshooting article in our Knowledge Center.

The quick answer is that you can probably tell by the quality of the video playback since RAVE delivers a user experience on par with running the media player locally. But here are some other telltales. When RAVE is working, a black rectangle will quickly flash by as the video begins to play. Server CPU usage will be much lower than if the video were being rendered on the server (for comparison, you can disable SpeedScreen Multimedia Acceleration on the console and try playing the same video). Searching for "FilterInt" in ProcessExplorer will show that DLL loaded by the media player's process.

Are there any enhancements that you would like to see to make it easier to discover that an additional codec needs to be installed on the client (or even on the server to support server-side rendering as a fallback)? For example, one possible enhancement would be for SpeedScreen Multimedia Acceleration to record RAVE events in the Windows Event Log.

Derek Thorslund
Product Strategist, Multimedia Virtualization

Scott Guthrie, a VP at Microsoft, recently blogged about a new release of Silverlight that will soon be ready for beta trial. Silverlight 1 introduced a new browser-based video player supporting a JavaScript/AJAX programming model. Silverlight 2 focuses on enabling the development of Rich Internet Applications (RIAs). An important point about RIAs is that they aren't just for the Internet. Silverlight 2 will enable "rich desktop Windows applications" for the enterprise, so it is of great interest to all of us involved with the Citrix Multimedia Virtualization Initiative. Although not offering the full 3D graphics capabilities of WPF (Windows Presentation Foundation), Silverlight is a strong subset of WPF that supports "2.5D" graphics effects including transparency. The UI framework provides support for animation, layout management, controls, data binding, and more.

Visual Studio 2008 will support Silverlight 2, as it does WPF, making it very easy for ISVs and other application developers -- even non-professionals -- to create rich client applications in their choice of programming language (C#, Visual Basic, JavaScript, etc.).

The beta release is just 4.3MB and installs in less than 10 seconds. Unlike WPF, Silverlight 2 does not require the .NET framework to be installed on the client. Silverlight applications run within a browser (Internet Explorer, Firefox or Safari) but can be migrated to standalone desktop applications using WPF and the .NET framework.

No doubt Silverlight 2 will be a big topic at Microsoft's upcoming sold-out MIX08 conference in Las Vegas!

Derek Thorslund
Product Strategist, Multimedia Virtualization

You may have already seen the Tolly Group's report on how SpeedScreen Progressive Display enables delivery of PACS images to healthcare workers over a variety of network types. But for me it is even more exciting to hear from customers actually experiencing this technology in the field. Recently I learned of a hospital network using XenApp 4.5 (formerly known as Presentation Server) to deliver radiography images from their Agfa IMPAX 6.2 image and information management system. I haven't asked permission to publish the name of the customer but I can share their observations with you. Interestingly, IMPAX 6 is billed by Agfa as a web-deployable PACS system since it offers a Java plug-in for Internet Explorer, yet the hospital found that performance over their WAN is significantly better using XenApp to publish the IMPAX application (Win32). On Windows XP PCs with at least a Pentium III processor and 256 MB of RAM (the oldest production PCs still in service across the 7,000 PCs on their network), performance is "exceptional". In fact, XenApp has successfully delivered "cine loops" where a series of up to 300 splices of a CT scan is displayed at 27 frames per second -- a very challenging use case! These observations were made with the users situated 5 miles down the road from the hospital's data center, connected over a gigabit network and through a 10 Mbps switch.

Have you started using SpeedScreen Progressive Display in your business? If so, please post a comment or send me an email.

Derek Thorslund
Product Strategist, Multimedia Virtualization

Remember the great demo video of OpenGL graphics acceleration that Lee Laborczfalvi did for us at the iForum App Delivery Expo? Project Pictor has come a long way since. The Pictor technology has been incorporated into a new Citrix product called Virtual Design Studio. And the beta program for Virtual Design Studio has now been announced. Citrix is now inviting customers in the Manufacturing sector who use Dassault CATIA v5 to participate in our White Glove Beta Program, scheduled to run from April 15 through June 30, 2008. For details, check out the beta invitation on our corporate web site.

Derek Thorslund
Product Strategist, Multimedia Virtualization

In recent years, we've seen widespread adoption of video streaming in the enterprise. Typical uses include employee training and corporate communications. In this 10-minute video, Citrix engineer Aureliano Lopez-Martin demonstrates SpeedScreen Multimedia Acceleration and explains how Citrix's RAVE (Remote Audio & Video Extensions) technology delivers video streaming with excellent quality -- including High Definition -- and very high server scalability.

To set the stage, consider the two basic alternative approaches to delivering streaming media from a centralized application or desktop delivery system. You can either render the video centrally and send it in a standardized compressed format to the client, or you can decode the native compressed media stream on the client device using the appropriate codec. Each approach has advantages and disadvantages.

Recently, I posted a video of Vista Aero Remoting, a technology currently being developed under project Apollo. The Apollo Vista Aero Remoting technology takes a generic approach to delivering whatever appears on the user's virtual desktop. The beauty of that approach is that it delivers a "full fidelity" user experience for whatever the user needs to view on the screen, whether it is a Flash or Windows Media video, a next-generation Windows application written in WPF or Silverlight, or any other application technology.

The RAVE technology behind SpeedScreen Multimedia Acceleration is an optimization specifically for streaming video and audio. It leverages client-side resources to increase server scalability (the number of concurrent users) and thereby reduce the cost per user. Take a look at this video and you'll learn about the advantages and requirements of the RAVE approach and get a glimpse into the future of this innovative technology. 

Derek Thorslund
Product Strategist, Multimedia Virtualization

(Click to hear Aureliano Lopez-Martin explain the RAVE technology behind SpeedScreen Multimedia Acceleration)

Our project Apollo technology for remoting Vista Aero and any multimedia application that can run on Vista just keeps getting better. This video gives you a sneak peek at the latest version of Apollo, demonstrated by Juan Rivera (Citrix Development Manager) in the Tech Lab at Citrix Summit 2008 in Orlando.

Recently, I blogged about three ways of delivering telephony functions to Citrix Presentation Server users. A reader commented: "I currently use the Avaya Softphone via Citrix for Remote Call Center agents, allowing complete in-the-office phone features that allow us to not rent office space." You can learn more about publishing the Avaya IP Softphone in the following document on Avaya's web site: http://support.avaya.com/elmodocs2/ip_agent/R7.0/125772.pdf

Derek Thorslund
Product Strategist, Multimedia Virtualization

One of the half dozen SpeedScreen technologies from Citrix is SpeedScreen Image Acceleration. Since I've been reviewing these technologies as part of my multimedia virtualization strategy work, I thought I'd briefly share some highlights of this valuable feature.

SpeedScreen Image Acceleration was introduced in Presentation Server 3.0 back in 2004 and is included in all product editions. It is one of the new features in last month's Mac client release (along with SpeedScreen Progressive Display and various other enhancements), and it is an important capability of XenDesktop, too.

Image Acceleration improves the delivery of photographic bitmaps and high detail synthetic images. If a bitmap looks as if it is probably photographic or highly detailed, SpeedScreen Image Acceleration can add an extra level of lossy JPEG compression to speed up the transmission of the image to the client device. Lossy JPEG compression is quite CPU intensive, but since it is applied only when there is enough image detail that the probability of payoff is high, server CPU is not consumed needlessly.

With modern applications, even a background image can have considerable detail. For example, there may be subtle color changes from left to right or top-down. Even icons these days are often high detail images with gentle graduation in color. JPEG is very good at handling pictures with many different shades of color.

Under most circumstances, the compression scheme is able to remove redundant data with minimal loss of information, and the image still looks good to the user. So SpeedScreen Image Acceleration is enabled by default. But sometimes, applying a high level of lossy compression to a high detail, synthetic (non-photographic) image will produce noticeable artifacts or smudging. So there's a trade-off between image quality and throughput. Since lossy compression isn't always desired, the settings for Image Acceleration are fully controllable by policies. The system administrator can choose the preferred compression level (high, medium or low) and may restrict the use of lossy compression to network connections below a specified bandwidth threshold. Lossy compression is not appropriate for certain applications where image fidelity is critical, such as Picture Archival & Communications Systems (PACS) used in Healthcare to view X-rays and other scans, except to improve responsiveness while an image is being scrolled on the screen; but that's a topic we can cover another time when we take a look at SpeedScreen Progressive Display.

Derek Thorslund
Product Strategist, Multimedia Virtualization

One of the most viewed Citrix blog posts of all time is Orestes Melgarejo's post, "To VoIP or not to VoIP". A lot of customers have expressed interest in delivering telephony functions to their users via Presentation Server. The purpose of this blog post is to highlight that there are at least three ways you can already deliver telephony functions with Presentation Server 4.5 today. I'll get into more detail on each of these currently available solutions in subsequent posts, but let's start with a brief summary:

1. Published softphone in "control mode".

There are softphones available today from vendors such as Avaya and Cisco that are Microsoft Terminal Services compatible and can be published on Presentation Server to control a physical telephone set. Likewise, Microsoft's Office Communicator client, a Unified Communications tool, can be used in this way. In control mode, you use the softphone application to make calls, redirect calls to any telephone, establish audio conferences, control telephony features, and so on.

2. Softphone application streamed to the user's Windows PC.

The application streaming feature of Presentation Server 4.5 Enterprise Edition and Platinum Edition can be used to stream compatible softphone applications to client devices. The softphone application then runs within a protected isolation environment. The softphone is never actually installed on the user's PC. This approach to softphone delivery centralizes management and reduces the risk of operating system instability from application conflicts.

At iForum in Las Vegas last year, Citrix, HP and Cisco jointly demonstrated softphone streaming to a Windows XPe thin client. Enabling telephony is one of the common functions of an embedded operating system. We're still accepting requests from customers who would like to field test this solution. Amazingly, it was all done with generally available product releases.

3. EasyCall.

EasyCall, powered by the Citrix Communications Gateway, is a feature of Presentation Server Platinum Edition. EasyCall provides a remote telecommunications capability without the need to purchase and support softphones. With its click-to-call function, users can click on any telephone number that appears on their screen, whether in a directory or any other application, and EasyCall will initiate a call to that number. EasyCall does this by calling the user first and then completing the call to the number on the user's screen. The user can specify whether they are using their office phone, home phone, mobile phone, softphone or whatever. Since all calls placed through EasyCall actually originate from the company's telephone system, long distance charges are reduced.

In addition to the three solutions summarized above, the Citrix Access Gateway deserves a mention in this context. The Access Gateway is capable of tunneling VoIP traffic (which is typically UDP) over SSL. There's a white paper in the Citrix Knowledge Center that explains how to enable the Cisco IP Communicator softphone through Access Gateway.

So, stay tuned for future blog posts where I will elaborate on each of these currently available methods for delivering telephony functions to your users via Presentation Server. And then I'll update you on where all of this might go in the future. Meanwhile, I'd be very interested in your comments on any of these solutions, the 'use cases' you believe are most important to address, and your own strategic thinking around delivering telephony functions to the enterprise.

Derek Thorslund
Product Strategist, Multimedia Virtualization

Whereas Citrix NetScaler is all about delivering web applications with outstanding performance, availability and security, the SpeedScreen Browser Acceleration feature of Citrix Presentation Server is focused on optimizing the performance of the web browser used to access those applications. Many Citrix customers deliver Internet Explorer and/or Mozilla Firefox to their users through Presentation Server for reasons well articulated by Brian Mirrotto and Rob Patterson in their iForum 2005 presentation Take Control of Your Users' Web Browser; in particular, easier management, better performance and improved security (see also Resolve Web browser security and compatibility issues). SpeedScreen Browser Acceleration ("SpeedBrowse" for short) improves the usability of Internet Explorer when accessing web pages that contain JPEG and non-transparent GIF images, two very common digital image file formats. (SpeedScreen Image Acceleration takes over for photographs and other high detail images.) It also optimizes the performance of Outlook and Outlook Express when viewing HTML-based email.

SpeedBrowse actually consists of several sub-features that work in tandem to improve browser responsiveness and reduce bandwidth consumption. Here's a high-level summary of the most important pieces that make up the SpeedBrowse feature:

• Optional automatic disabling of GIF animations. By default, SpeedBrowse disables Internet Explorer's "Play animations in web pages" option. This setting reduces bandwidth consumption and enables the resulting static GIF images to be delivered over the SpeedBrowse virtual channel.
• High-level browser hooking. SpeedBrowse uses high level hooks into Internet Explorer to intercept JPEG and GIF images before they are decompressed. Images can be sent to the client in their native compressed form, minimizing bandwidth consumption.
• Dynamic JPEG image recompression. JPEG offers multiple levels of compression. By recompressing a JPEG image at a higher, more "lossy" level of compression, bandwidth consumption can be further reduced, at the expense of image quality. Presentation Server Enterprise Edition and Platinum Edition offer a "Determine when to compress" option that dynamically evaluates image size and available network bandwidth to automatically decide how much compression to apply.
• Background image delivery. SpeedBrowse sends compressed images in chunks over a separate SpeedBrowse virtual channel so as not to block the Thinwire command protocol. The user can scroll and use the Back and Stop buttons of the browser with excellent responsiveness as images are downloaded at lower priority in the background.
• Client-side image caching. SpeedBrowse caches compressed image chunks on the client. If the server detects that a chunk is already in the client's image store, it will not resend that chunk. It only needs to send an identifier. By caching image chunks on the client, web pages that are revisited display much faster and bandwidth consumption is reduced because the server does not need to retransmit previously sent images. Furthermore, decompressed images are added to the client's cache as bitmaps so that these images don't need to be decompressed each time they are drawn. This provides a significant performance boost when a web page is scrolled because scrolling generates multiple drawing operations for each image on the page.

Of course, there are some limitations, too. SpeedBrowse is not compatible with web pages that include Adobe Flash content. And it would be nice to see an enhancement to handle PNG images, which offer more vibrant color than GIFs.

When you look at the multiple facets of SpeedScreen Browser Acceleration, you can see why it adds up to a tremendous feature for accelerating web browser performance. A study by Doculabs (click for summary press release or full report) published shortly after SpeedBrowse was introduced concluded that Presentation Server provides "200% to 250% more efficient network bandwidth utilization than locally installed browsers (depending on the configuration and tuning options selected)" and "may provide users with a two-fold or greater increase in page loading performance" on low bandwidth connections. This testing was done against a set of 99 web pages including commercial sites such as Google, Yahoo and Microsoft.com. 50% of the pages were graphically intense (over 95% of the total page download coming from image loading). Using a browser delivered via Citrix Presentation Server resulted in a transfer of 55% less data than when browsing with a locally installed browser, resulting in noticeably faster response times. The SpeedBrowse feature is a big contributor to this outstanding performance.

In the time since the Doculabs report was written, we've witnessed the emergence of numerous Javascript-enabled web sites (Gmail, for example). These days, there's a lot more data getting sent down to the browser, which now is becoming a pseudo operating system executing all these applications. It's often a lot less network intensive to send the image representation of the web page through ICA rather than downloading the entire page to the client. This is especially important if the client is at the end of a limited bandwidth pipe.

Derek Thorslund
Product Strategist, Multimedia Virtualization

We recently conducted some tests to confirm that Office Communications Server 2007 can be delivered via Citrix Presentation Server 4.5. While these are not "official" test results, I thought many of you might appreciate an early look at what we found in case you're considering rolling out OCS 2007.

Office Communications Server, the successor to Microsoft Live Communications Server 2005, is Microsoft's entry in the Unified Communications space. It brings together Voice-over-IP (VoIP), Instant Messaging (IM), audio and video conferencing, and integration with Microsoft Office. OCS includes presence information so you can see at a glance whether someone is available to receive your phone call or instant message.

We didn't test video conferencing. That would require USB webcam support on Presentation Server. Our focus was on the Instant Messaging and Microsoft Office integration features of OCS 2007.

We published the Office Communicator client on Presentation Server and successfully used its Instant Messaging and presence functions. OCS integrates presence information from multiple sources including the Outlook calendar and Out-of-Office Assistant. From an e-mail message in Outlook, you can view the presence information for each addressee and then initiate real-time communications from within the message without switching applications.

Office Communicator can also be used to control a physical telephone set. For example, you can instruct Office Communicator to place a call in your behalf and, leveraging your telephone system, it will ring your phone (office, home, or mobile) and then call the other party and bridge the connections. You can't yet use Office Communicator on Presentation Server as a pure softphone with voice-over-ICA; one of the reasons is that softphones need to open the audio driver more than once (ringtone/busytone, voice) and the current audio driver in PS 4.5 FP1 doesn't support that. (We previewed an enhanced audio driver for softphone support and voice-over-ICA in the Tech Lab at iForum in October and I'll blog on various aspects of voice-over-IP in the new year.)

If you have any experiences running Office Communicator on Presentation Server that you'd like to share, please write a comment on this blog post. And I'll keep you informed as we learn more about delivering Unified Communications via Presentation Server and XenDesktop.

Derek Thorslund
Product Strategist, Multimedia Virtualization

I'm back from my 7-day Eastern Caribbean cruise and of course the first thing on my mind is my Multimedia Virtualization blog! We've just migrated the Citrix blog site to an updated system so I had a few transitional issues to work through, but now I'm ready to share with you Part 2 of my series on optimizing Adobe Flash performance on Citrix Presentation Server. (Click here to read Part 1.)

There's definitely more to optimizing Adobe Flash than configuring SpeedScreen Flash Acceleration ("SpeedFlash") and making sure you have any required hotfixes to handle newer versions of Flash. One of the features of Presentation Server that can have a very substantial positive impact on Flash performance (animations and video) is Queuing & Tossing. This feature shows up in the management console as "Discard queued images which are replaced by other images" or "Discard redundant graphics operations", depending on which version of Presentation Server you're running.

The Queuing & Tossing feature of Thinwire briefly queues GDI draw commands and, before sending them over ICA, inspects the stack in reverse order (LIFO) to allow tossing of obsolete commands (those which have been overwritten by subsequent commands). The queuing period is short enough (30ms) that it doesn't degrade the responsiveness of the application; in fact, performance is significantly improved because draw commands that are logically redundant are discarded.

The tossing algorithm was enhanced in Presentation Server 4.5 (Ohio) to look for more graphics constructs. The tossing algorithm now uses a 1-bit-per-pixel map of the session screen. And it can detect complete self-contained 'frames'. As a result, Thinwire will either send the entire frame to the client as a self-contained entity or toss it completely. These improvements to the tossing algorithm further reduce the amount of data that needs to be sent over the wire. Along with reduced network bandwidth consumption, network efficiency (data bytes per frame) is increased. And the user experience is better because the entire frame gets updated at once rather than in pieces.

So, just how big a difference does all of this make? I recently spoke with one of our engineers who has been taking performance measurements with Flash videos. In his testing, he found that enabling Queuing & Tossing reduced bandwidth consumption by more than 3 times!

In addition to the new framing behavior of Queuing & Tossing in PS 4.5, just-in-time output behavior has further improved Flash performance. Flash video playback with PS 4.5 is noticeably smoother. And CPU consumption is lower, which increases server scalability (number of simultaneous Flash users per server).

There's still quite a bit more to tell you about Adobe Flash performance optimization, so stay tuned for my next installment on this topic.

Derek Thorslund
Product Strategist, Multimedia Virtualization

In my conversations with customers at our iForum App Delivery Expo in Las Vegas a few weeks ago, the topic of Adobe Flash came up several times. It became apparent to me that many Citrix system administrators are looking for guidance on how best to configure Presentation Server to support access to web sites with Flash content, and they're wondering what future enhancements Citrix has on our technology roadmap. So here is the first in a series of blog posts about optimizing Flash performance.

Flash is indeed a key focus area for the Citrix Multimedia Virtualization Initiative. Over the past few years we introduced various enhancements and tweaks to Presentation Server to help customers optimize the user experience when viewing Flash animations and videos. We also offer NetScaler to dramatically accelerate the delivery of web applications, including apps with Flash content. And there's more to come...

The reason for this continued attention to Flash is the growing prevalence of Flash-based content. Based on input I received from two leading Content Delivery Network vendors, it looks like Adobe Flash has now captured at least 10% of the enterprise market and is enjoying rapid growth. And a Forrester survey ("Enterprise Browser and Desktop Trends") of over 2,000 large enterprises found the Adobe Flash player installed on 98% of desktops.

The obvious starting point in our discussion of Flash performance is the SpeedScreen Flash Acceleration feature ("SpeedFlash" for short) introduced in Presentation Server 3.0. You can enable SpeedFlash to be on at all times or just over low bandwidth connections (less than 150Kbps). SpeedFlash automatically adjusts the Flash player to use simpler graphics (for example, no smoothing or anti-aliasing). These simpler graphics can be more effectively compressed, thereby reducing bandwidth consumption. CPU usage is reduced, too, which translates into higher scalability (more concurrent users per server).

SpeedFlash looks for specific binary file names. Here's where things can go wrong. The SpeedFlash code in Presentation Server 4.0 looks for flash.ocx and won't do its trick unless it finds that file. You may be running a version of the Flash player with a different binary file name. Presentation Server 4.5 was updated to also accept flash8.ocx, flash8b.ocx or flash9.ocx. But what do you do if you're still running Presentation Server 4.0?

There's a hotfix for PS 4.0 [NOTE: this hotfix is for Windows Server 2003] that adds support for Adobe Flash versions 7a, 8, 8b, 9, 9c, and 9d. You'll find the details at http://support.citrix.com/article/CTX115426 (login required). [NOTE: If you have trouble with this link even after logging in, just do a search for CTX115426. I've noticed that the link can take a long time to resolve. An approved support contract is required to access limited release hotfixes and hotfix articles.] The hotfix number is PSE400R03W2K3091. And I expect there will be future hotfixes as new versions of Flash are introduced that have a different binary file name or require new SpeedFlash code to achieve the task of adjusting the Flash player to use simpler graphics.

[UPDATE: A hotfix for PS 4.0 with HRP04 on Windows Server 2000 was made available on March 10th. Customers with an approved support contract can find the article describing this hotfix at CTX115555. The hotfix number is PSE400R04W2K012. This hotfix adds support for Adobe Flash versions 7a, 8, 8b, 9, 9c, and 9d.]

So, does it work? Obviously the current SpeedScreen Flash Acceleration technology is not as advanced as SpeedScreen Multimedia Acceleration, which leverages client-side resources to greatly improve server scalability and provide a just-like-local user experience for a long list of media types that can be decoded with a DirectShow codec. Yet the measurements I've seen for SpeedFlash show an impressive 22% average reduction in bandwidth consumption (the actual figure will vary according to the content).

If your users will be accessing Flash videos, I recommend setting SpeedFlash to be always on, rather than limiting it to just low bandwidth (dial-up) connections.

Audio settings are also important to consider since if you're watching a Flash video it more than likely has an audio track, too. I recommend Presentation Server's Medium Quality setting as the best compromise between sound quality and bandwidth consumption. The Low Quality setting does not make for a very good user experience, and the High Quality setting uses up a lot of bandwidth (roughly 1 Mbps). Improvements to audio support are another part of the Citrix Multimedia Virtualization Initiative (see "Now playing - The Ulysses Audio Codec").

I'll have some more "secrets" for optimizing Flash performance in a subsequent blog post.

Derek Thorslund
Product Strategist, Multimedia Virtualization

It's great to see the major desktop appliance (thin client) vendors, including HP/Neoware and Wyse, rallying around the Citrix Multimedia Virtualization Initiative. A notable example of how our ecosystem partners add value is TCX Multimedia 2.0 from Wyse, a streaming media solution (think training videos and corporate broadcasts accessed in an ICA session). At iForum 07 - The App Delivery Expo - Wyse and Citrix announced that TCX Multimedia 2.0 has achieved Citrix Ready status (see the press release from Wyse).

TCX Multimedia provides an intriguing complement to SpeedScreen Multimedia Acceleration (one of several technologies explained in Brian Madden's video on SpeedScreen). As with SpeedScreen Multimedia Acceleration, the media player runs on Presentation Server but the multimedia (video and audio) data stream is decoded and played locally on the client with a virtual channel being used for start/pause/stop and other controls. And both technologies deliver a great user experience by leveraging the processing power of the client device while maintaining the advantages of a centralized application delivery model. The key difference with TCX Multimedia is that the multimedia stream can be delivered directly to the user desktop appliance from a local media server instead of going through the data center. TCX Multimedia attempts to establish a direct path from the source to the client. This isn't always possible and the solution will fall back to obtaining the media stream through ICA when necessary to traverse firewalls, but when it is possible it has the benefit of consuming less network bandwidth and reducing the load on Presentation Server, which is good for performance and scalability (number of concurrent users per server). The beauty of the TCX Multimedia software is that it can intelligently and dynamically decide when to redirect the multimedia stream.

Another noteworthy feature of TCX Multimedia is its multicast support (limited to MPEG-1). Multicast provides a very efficient way of delivering the same multimedia stream to many users at the same time. Suppose your CEO is addressing the troops for a quarterly state-of-the-business update. Potentially a large number of people want to watch the videocast simultaneously, in real time. With multicasting, each individual packet can be sent to many endpoints simultaneously, consuming much less network bandwidth than if the media stream had to be replicated for every user. And multicast uses UDP/RTP. UDP (User Datagram Protocol) is better suited to live videocasts than TCP/IP because it is a "best efforts" protocol that doesn't get stuck doing retransmissions if some packets are lost; timeliness is more important than completeness. RTP (Real-Time Protocol) adds timestamps and other controls to help keep the audio and video in sync.

TCX Multimedia supports a broad set of media formats: MPEG-1, MPEG-2, MPEG-4 part 2, WMV (Windows Media Video), WMA (Windows Media Audio), AC-3 (Dolby Digital) and MP3. The notable omission at this time is Adobe Flash.

What next? Wyse notes that support for Linux is "coming soon".

Derek Thorslund
Product Strategist, Multimedia Virtualization

In this 5-minute video, Citrix architect Lee Laborczfalvi demonstrates technology from project Pictor, a key component of the Citrix Multimedia Virtualization Initiative. Pictor leverages high performance GPU hardware to accelerate interactive 3D graphics applications built on OpenGL, a widely used graphics API that offers a broad set of rendering, texture mapping, special effects and other powerful visualization functions. OpenGL is commonly used by CAD/CAM/CAE, GIS (geographic information), medical imaging and data visualization applications. Click here for a video demonstration of Pictor from the Tech Lab at iForum 07 - The App Delivery Expo.

Up until December 14, 2007, Citrix is recruiting select customers and partners who use Dassault CATIA to participate in a 2-day Design Council for Pictor. Participants will preview and test early Pictor technology at the Citrix office in Santa Clara, California, interact directly with the Citrix Pictor team, provide feedback and influence the future direction of the solution. For further information, please contact Citrix Product Manager Debbie Fox (Deborah.Fox@Citrix.com) or Product Marketing Manager Michael Chang (Michael.Chang2@Citrix.com).

Derek Thorslund
Product Strategist, Multimedia Virtualization

(Click to watch Lee demonstrate the Pictor technology -- and stay tuned for a bonus feature at the end)

One of the most exciting demos at iForum 07 - The App Delivery Expo - was the project Apollo demo by Henry Gancedo to Mark Templeton and the audience at the closing keynote. Click here to view a 6-minute video of the Apollo demo in which Henry gives us a preview of technology for delivering a Vista Aero desktop - complete with translucent "glass" effects, Flip 3D animation and a highly graphical WPF application - to a non-Vista desktop appliance. (http://www.brightcove.tv/title.jsp?title=1279697348)

Derek Thorslund
Product Strategist, Multimedia Virtualization

Finding the optimal balance between audio quality and bandwidth consumption has never been easy. Most Citrix customers today choose our Medium Quality audio setting to obtain the best compromise for the majority of use cases. But in the Citrix R&D labs in Fort Lauderdale, our computer scientists are cooking up something much better. View my interview of Modesto Tabares, one of the lead engineers working on Citrix's Multimedia Virtualization Initiative, to learn about a new voice codec codenamed Ulysses that offers a win-win proposition.

Derek Thorslund
Product Strategist, Multimedia Virtualization

If you'll be at iForum 07 - The App Delivery Expo - in Las Vegas, October 22-25, and you're interested in the delivery of multimedia applications and desktops, here are a few sessions and focus groups that I recommend you attend to learn more about Citrix's Multimedia Virtualization Initiative. Focus group attendance is limited but I'll try to get you in; send me an email if you'd like to participate.

Session #213: Deliver Graphically Intensive Applications with Citrix Presentation Server
This session will be held twice; at 12:00 noon on Monday, and again at 4:00pm, in Mandalay J

Session #201: The Future of Citrix Presentation Server: Windows Server 2008 and Beyond
Wednesday at 4:30pm in Mandalay L

Session #906: The Impact of Next-Gen App Architectures on App Delivery
Wednesday at 10:00am in Mandalay A/B

Session #410: Combining Citrix and Thin Computing: It's a Whole New Game
Presented by Wyse
Tuesday at 3:30pm in Mandalay I

Session #405: New Application Delivery Developments for HP Thin Clients
Presented by HP
Wednesday at 2:30pm in Breakers K/L

Focus Group: Rich Multimedia (Graphics/Video)
An opportunity to provide your input on priorities and requirements!
Tuesday October 23rd, 4:30pm-6:00pm
Limited attendance

Focus Group: Voice-over-IP and Unified Communications
Wednesday, October 24^th, 2:30pm-4:00pm
Limited attendance

And don't forget to drop by the Tech Lab in the Exhibit Hall where you'll find more than half a dozen demos related to multimedia virtualization.

Derek Thorslund
Product Strategist, Multimedia Virtualization

The Citrix Multimedia Virtualization Initiative is an ongoing cross-product R&D effort focused on multimedia desktop and application delivery. Watch my video blog for a 6-minute introduction to the Multimedia Virtualization Initiative and learn how Citrix is continuing to enhance the ICA protocol to provide the best end-user experience as graphics and rich media technologies evolve.

My video blog references Microsoft Windows Presentation Foundation (WPF) technology and a fast-paced video that will give you a great appreciation for what WPF applications are all about. You can find Microsoft's WPF video at http://wpf.netfx3.com/blogs/news_and_announcements/archive/2007/05/10/wpf-momentum-video.aspx.

Derek Thorslund
Product Strategist, Multimedia Virtualization