It's always nice to know how an enterprise application will perform before it goes live – before your phone lights up with calls from annoyed users. One way to cut down on angry calls is to use a WAN simulation package and test before deployment. There are a few ways this can be done using off-the-shelf hardware and open source programs, but you generally get what you pay for (or don't), and miss out on the test automation, ease of use, and comprehensive reporting that accompany commercial products.

The Bottom Line Shunra Virtual Enterprise 5.0 Shunra Software, shunra.com Very Good  8.6 criteria score weight Manageability 8 30% Performance 9 25% Scalability 9 25% Setup 8 10% Value 9 10% Cost: Basic unit: $50,000 Platforms: Any Ethernet network; 10/100/1000Mbps copper and fiber media support. Microsoft Visio and MySQL (both included in package). Bottom Line: Anyone who needs to test enterprise-wide applications over varying conditions should give the Shunra VE WAN emulation suite a good, hard look. It is expensive but provides the tools needed to construct realistic test scenarios and capture all relevant data about the traffic over the WAN. The bundled applications -- VE Modeler, VE Reporter, VE Transaction Manager, and VE Analyzer -- work together to help automate testing and determine how varying WAN conditions can affect network performance. About our Reviews and Scoring Methodology

[ ShunraVE 5.0 was selected for an InfoWorld Technology of the Year award. See the slideshow of all winners in the networking category. ]

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Shunra's VE (Virtual Enterprise) 5.0 allows IT to create a complete representation of the network, including routers, gateways, and redundant connections, in the space of a single workbench. With VE, IT can create just about any set of WAN conditions, complete with multiple routes and link speeds (up to OC12), latency, packet loss, and various link impairments. Shunra bundles a specialized copy of Microsoft Visio to define the network's properties and other characteristics with VE 5.0, and it includes the new VE Transaction Manager and VE Analyzer.

Good things just get better
My experience with Shunra goes back a few years, and over that time, I have seen the product mature to the point where it has to be considered an indispensable tool for anyone rolling out a new network-based product or needing to know how a data replication will perform across the WAN. Most recently, I used Shunra in a round of WAN acceleration and optimization tests and have come to rely on it completely because of its ease of use and consistency. I cannot tell you how much I appreciate loading up a WAN definition and knowing it will behave the same every time it runs.

Installing the hardware onto the test bench took only five minutes. Simply connect to the management port to the administrative network and the test hardware to the other 10/100Mbps copper or 2 Gigabit fiber interfaces, and you are almost ready to go. The brain of the operation is the VE Suite that installs on a client PC – in my case, a Windows XP Pro computer. The suite will install a copy of MySQL during the installation process to track test results. Unlike last time, I had no trouble installing the 5.0 package on the same hardware as the database.

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As with previous versions, VE Modeler is the starting point for all things simulated. Modeler uses Visio 2003 to draw out the network, including varying link speeds, gateways, and impairments. Modeler shapes include Packet Modifier, for dynamically changing a packet's contents as it passes through the appliance; Twister, for changing traffic paths during simulation; and both uni- and bidirectional links. The gateway shape has been enhanced to support fail-over routing rules, and the packet decoder can export to third-party reporting tools.

Analyze this
One of the most powerful tools included in this release is VE Analyzer, an application that greatly extends Shunra's reporting capabilities. Analyzer allows admins to drill down into individual transactions to help identify the cause of performance problems. It includes a very useful list of canned reports, such as a transaction breakdown summary, throughput and bandwidth utilization, VoIP analysis (including MDI and VQFactor reports), and a SIP conversation diagram (very helpful when troubleshooting VoIP call problems). The amount of data captured by Shunra and made available through VE Analyzer alone is nearly worth the cost of the system.

One report in particular, the infrastructure breakdown summary, provides a deep look into an application's conversation between client and server. This report highlights the time each transaction spends on each part of the conversation: the client setup, the time spent on the network, and the response time by the server. For software developers, this report goes a long way to help understand exactly what the application is doing on the network and, by varying the WAN parameters, how latency and link speed play a part in overall performance.

As with any good tool, experience is key to getting the most out of it. I would be lying if I said VE Analyzer was easy to use. But with some time knee-deep in the digital stream with pan in hand, it gets more intuitive and easier to dig out the data nuggets you're looking for.

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Another new application in the VE suite is the VE Transaction Manager. This component takes advantage of integration with VE Modeler and VE Analyzer to automate the QA test process. Transaction Manager also works with third-party test tools, such as Mercury's LoadRunner and Borland's SilkPerformer, to make scalability testing – with tools admins are already using – even easier. Transaction Manager stores all test results in VE Analyzer, consolidating the results and allowing for drill-down analysis.

For example, I created a test scenario to find out how varying WAN conditions affect WAN performance for a specific Web server. I used the combination of LoadRunner and Shunra to craft a test that scaled up to 1,000 concurrent users over five different WAN links. Once it was defined, I ran the test, then used VE Analyzer and Reporter to inspect the results. One thing to keep in mind is that the number of iterations is based on the number of WAN links and client stepping rate; my test took overnight to complete just because of the number of tests that had to run.

Overall, the Shunra VE is a fantastic platform from which to test applications and devices over nearly real-world WAN emulations. I love that the emulation is consistent and predictable and is the same each time it runs. VE Analyzer and Transaction Manager are great additions to the suite and make Shunra VE that much better.