Network World
When CEOs request expansion of streaming media at their companies but don’t increase its IT budget, an inexpensive option is Vividon Inc.’s Streaming Delivery Accelerator. The SDA is a very low-cost, yet high-density cache dedicated to streaming media delivery and Vividon Service Manager is a secure and intelligent management layer interface for SDA.
We awarded SDA and VSM our World Class Award for its high performance, and – by virtue of a Web-based management system – high manageability and functionality. Considering its size and resources, the company exhibits outstanding pre- and post-sales services in customer facilities.
Caches aren’t new in the network. Vendors, such as Network Appliance Inc., CacheFlow Inc. and Inktomi Corp., that build caches for static text and images recognize that differences in file size, sequence and latency sensitivity, as well as bandwidth requirements for streaming media, require special attention. While many cache vendors support streaming media, Vividon says a different architecture is needed to achieve the lowest price/performance point. According to Vividon, traditional cache makers can’t reach Vividon’s price. It’s unusual to find a new product that costs less and offers more than existing alternatives (at least in streaming), but this one does.
A challenge for Vividon in positioning its systems is that the combination of SDA and VSM create more than “just a cache.” SDA can be considered a server and a cache, depending on where it is placed and how it is used. It stores content and also delivers it in response to client requests. It supports on-demand services and live-streaming services. It stages content, but also offers user support for videocassette recorder-like controls. Through an intuitive Web-based interface, VSM can configure, monitor and manage as many remotely deployed SDA systems as your network requires. However, given the storage capacity and the throughput of each unit, you many not need many SDAs.
Some heavy lifting
An SDA2000-series system packs 50 pounds of interfaces, hard disks and power supplies into a mere 16.75 inch by 28.75 inch by 3.3 inch space. Because of the high density of these systems, Vividon leads the customer through a simple process to ensure that SDA is shipped with appropriate rack-mounting brackets (and screws) and is installed as close to the ground as possible. Every step is carefully diagrammed in the installation guide.
Vividon is equally diligent about ensuring that network interfaces are properly ordered and pre-configured. Options include two 10/100 Ethernet interfaces for the 1U (1.75 inches) systems, one Gigabit Ethernet (copper or fibre) for the 2U systems and dual Gigabit Ethernet (copper or fibre) for the 5U systems. All the interfaces are engineered by the company to provide maximum streaming throughput and currently must be installed by Vividon technicians prior to the units shipping. By accidentally inserting our network cable into a jack and failing to get connectivity, we learned that the native platform on which SDA is installed also has a (Dell Computer Corp.) built-in network interface that is disabled.
Running the “sda_field_install” utility causes SDA to contact VSM. Once that is completed, it should be the last time you need to interface directly with an operational SDA in a network via a keyboard. From this point, all media and SDA management and SDA report viewing is performed via VSM’s graphical user interface console.
Packing a performance punch
By virtue of their significant throughput (160M bit/sec for the 1U, 400M bit/sec for the 2U and 650M bit/sec for the 5U), Vividon’s SDA-2000 requires at least a Gigabit Ethernet environment to achieve performance potential. Anything less will impede the streaming media traffic, reduce the number of streams delivered by the (SDA-2000) system and defeat the purpose of the original purchases. Testing performance is fundamental to establishing Vividon’s price/performance value claims.
In our tests, we saw that SDA can sustain throughputs that one might expect in a production network environment. In one test, SDA-2000 delivered 4,500 concurrent streams of 56K bit/sec each without dropping a packet. Because SDA was programmed to report any peaks in activity to VSM, we saw an alarm in the system’s monitoring page. In another test of 1,200 connections with an aggregate throughput of 380M bit/sec (approaching the system’s maximum of 400M bit/sec) we also triggered an alarm. When the system reached its threshold limits, the next stream request was denied, instead of granting the request and causing an overall reduction in performance to existing clients.
In another performance test with Vividon’s Swamper load generator, we sent 396 simultaneous requests for the same file, mimicking a case in which one file is very popular. In this situation, SDA-2000 delivered all the files successfully and consistently. During this request by Swamper, we watched the same video file play back on a Windows 2000 Server in Windows Media Player 7.1. The media player’s statistics window indicated that no packets were lost or recovered during the session.
Tests with and reports generated by Windows Media Load Simulator (WMLS) similarly indicated that all requests were met. When the test was finished, we reviewed and printed usage information about user (in this case Vividon’s Swamper and WMLS) interactions with files on SDA via VSM reports viewer. Information about the network, based on the SDA logs, and information about users and content can be viewed in separate interfaces, but data and reports cannot be exported. Vividon recommends that customers explore products from partners such as Lariat (www.lariat.com) to implement custom billing and reporting systems as needed.
Functionality and interoperability
An issue that has long limited the functionality of products designed to deliver streams is the lack of standards (or the high number of standards) in the field. SDA interoperates with networks and standards via support for multiple protocols, such as HTTP, Microsoft Media Server, RealTime Streaming Protocol, multiple content types, including streaming audio/video (in QuickTime, Real Media or Windows Media), Flash animations, and any static files such as Web pages and images. SDA is also Windows Media certified, meaning that Microsoft put it through a battery of more than 500 tests created for verifying compatibility of caches with Microsoft file management and delivery protocols.
SDA and VSM also produce standard log files that can easily integrate with billing, quality-of-service management and service-level agreement systems.
Although populating content into the directories on VSM was laborious and surprisingly “manual,” once that was done, many of the processes around streaming media management were automated.
The manual and user guide are well written, so customers should run into few problems once they leave the command-line interface. But if some of the commands or prompts in VSM aren’t clear, there is robust context-sensitive help preloaded on the VSM server during the software installation.
Affordability
This product is not designed for occasional or lightweight streaming applications. But for a corporation or content provider with an appetite for streaming that consumes thousands of simultaneous streams, the economics of Vividon’s products are compelling.
For example, assuming collocation costs of US$150 per 1U, electricity at 5 cents per kilowatt-hour, an initial capital outlay of $30,000 for Vividon’s hardware and the server on which VSM operates, and that the equipment will be in use for 36 months, SDA will cost the customer approximately 5.3 cents per 100 hours streamed compared with 22 cents to 24 cents per 100 hours streamed using a similarly provisioned and loaded set of caches from competing vendors or off-the-shelf servers.
The alternatives, based on published (not tested) cache vendor specifications, require between 5U and 10U of rack space for cache and storage capacity, and cost between $135,000 and $140,000.
In addition to dramatic differences in initial purchase prices, the recurring cost associated with alternatives (servers or caches) that use more rack space further tip the scales in favor of Vividon’s high-density solution.
Conclusion
If you’ve been banging your head looking for a streaming media investment, the Vividon solution is a steal. The product’s performance was great in every respect, and we believe the competitors will find it difficult to match Vividon’s SDAs, even in real-world environments.
Perey is president of Perey Research & Consulting in Placerville, Calif. She can be reached at cperey@perey.com.
How we did it
We installed Vividon’s SDA-2000 and VSM software Release 1.0 on a Dell PowerEdge Pentium III server running Red Hat Linux 7.1 and connected both to a Gigabit Ethernet network on which a Windows 2000 Professional client (running Microsoft’s Windows Media Load Simulator and Windows Media Player 7.1), and Vividon’s Swamper tool were previously installed. We used the Linux machine to provide DNS services to the networked units. An Extreme Networks Summit 7i with Gigabit copper interfaces provided ample bandwidth between SDA, VSM, clients and the various load-testing tools.
Due to the extremely data-intensive nature of a performance test of this type, Vividon developed a high-throughput testing platform called Swamper (and uses its own Quality Assurance lab). Via a command-line interface, Swamper places requests for different pre-populated media and measures the response of SDA.
We also tested performance, though far from maximum throughput, using the Microsoft Windows Media Load Simulator (WMLS) that we downloaded from the Microsoft Windows Media Web site (www.nwfusion.com, DocFinder: 7121) SOMETHING MISSING HERE menu Select Windows Media 7 Resource Kit Beta 3 from Windows Media Tools and Services. Choose Custom Installation and download “wmrk7_net.exe”).
We uploaded sample content (one 3-minute file encoded at 56K bit/sec, 100K bit/sec, and 1M bit/sec) on to SDA-2000 via VSM. We ran more than a dozen performance tests on the network by using some pre-programmed scripts in Swamper and using the WMLS interface. We varied the number of simultaneous sessions, the bandwidth of the files requested and the intervals at which the requests were made. We viewed test results and SDA reports in the VSM Web interface.
Installation details get a little hairy
Before SDA can be truly functional, the VSM application must be installed on a dedicated server running Red Hat Linux Version 7.1. Vividon provides a CD-ROM with Red Hat Linux to install on your server if it is not currently running 7.1 software. This took longer than expected because of some conflict between the image on the CD and the Compaq ML330e server ordered for the testing. After nearly six hours of troubleshooting using Vividon’s excellent online customer support system and telephone conferences, and guaranteeing that there was no hardware failure, we switched to a Dell server with Linux 7.1 preinstalled.
The VSM install utility installs VSM software on the Linux computer. Among other tasks, the installation automatically creates a staging directory where you can add content files to distribute to the SDAs in the network. VSM examines and converts all streaming media content into a format the SDAs can manipulate and deliver with maximum efficiency. Nearly all subsequent tasks on VSM are performed in a Web graphical user interface (GUI), making it not only easier for a non-Linux user, but also accessible from any secure IP-connected location.
Ultimately, the security of the SDA network depends on the security of this Linux server that acts as the service manager. Vividon has password-level support at several levels, and the VSM GUI is a secure Web interface that (via Secure Sockets Layer certificates) encrypts and deciphers all communications.
Once the VSM software has been installed, is ready and its operator runs the register_sda utility, the system integrator or installer installs a utility and configures the SDA for the enterprise network. Familiar to Unix users, the proprietary operating system’s command-line interface prompts the installer for 59 different specifics, ranging from the elementary SDA host name and logon information to dozens of streaming media-related parameters, such as ping interval, connection idle timeouts for each media format and what to do if the system reaches various benchmarks such as HTTP bandwidth maximums. Eighty percent of these have defaults suggested and the user would find it much easier to have them preloaded by Vividon in the register utility.
Prices listed are in US currency.
