Designing an enterprise network to be built from scratch, or planning major changes to an existing infrastructure, is a combination of art and science that separates expert network engineers from the pack. Often, it's an arduous process that's only visible to those outside the administrator group when it goes wrong. This month I'll focus on products that make the daunting task of network design almost simple.
The market for network design tools that stand out from the crowd is far from mature. For many network engineers, designing a network is a necessary evil that's made only slightly more tolerable by a layout design tool such as Visio. In fact, the design process can be aided significantly by software that discovers your existing network infrastructure, provides an intuitive interface for planning growth and allows you to estimate the impact your proposed changes will have on your network. At least, that's the idea. In reality we're not quite there yet, but a number of products are getting close.
Compuware Predictor (formerly EcoPredictor)
Although there probably aren't any products available that truly combine all of the functions mentioned above, there are still several that have enough to offer to begin to shine. As a product for enterprise networks with tens of thousands of nodes, Compuware's Predictor gets high marks for accurately calculating the effects of proposed changes to a network and does a moderately good job of offering a straightforward interface with which to design those changes. The software's reporting tools offer a range of functions including recommendations based on proposed changes and charting of various network statistics.
On the other hand, Predictor doesn't offer network discovery capabilities, which could be a major drawback if you need to make significant changes to a large-scale network. To mitigate this hole in its feature set, Compuware has designed Predictor to import data from a wide variety of network discovery tools including a number of third-party applications, as well as Compuware's own EcoScope, but this requires the added cost and complexity of a separate piece of software.
Microsoft Visio 2002 with Enterprise Network Tools option
While Predictor lacks network discovery functionality and a truly standout interface, Visio sets itself apart with these aspects of network design, but lacks the ability to simulate the impact of proposed changes on the network. In fact, Visio could be more accurately be called network diagramming software than network design software, since that's where it really excels.
Visio's familiar interface and wizard-based setup makes it by far the most intuitive, in terms of layout, of the three pieces of software discussed here. Yet Visio's most powerful feature is probably its network discovery ability. The built-in Simple Network Management Protocol (SNMP) discovery engine will map just about anything on your network, pull information from Active Directory, Novell eDirectory and other user databases, and store it all in an Structured Query Language (SQL) server database for future use. The downside is that this process is reportedly fairly sluggish and once you've collected the data and made your proposed changes, calculating performance and spotting potential bottlenecks will be reduced to educated guesswork.
Competing with Visio 2002 in the network discovery category is NetFormx DesignXpert. Which software you will prefer in the network discovery category probably depends a great deal on the devices in your network. If you run Active Directory and are Microsoft and 3Com heavy, you'll probably prefer Visio, while DesignXpert should fare better with Cisco-centric networks. Either way, DesignXpert, like Visio, uses SNMP to build a map of the network and list detailed information about network devices. Where Visio shines in the interface category, however, DesignXpert offers additional features via its configurator tool.
DesignXpert's configurator dialog opens when devices are added to the network. It tracks such items as what switch modules are needed when connecting specific devices, or how many blades a given router will require based on the number of devices connected to it. The software can then generate a bill of materials with details on the components, memory, firmware etc. for each product and even calculate estimated costs based on the latest product pricing information. While this might not be the tool for adding one or two switches to a closet, it could make selling the CEO on a "new" network a breeze.
In the end, there isn't yet a single tool that will quickly and easily allow engineers to design networks, plan upgrades, anticipate performance problems and present a well-organized report to executives all in one package. Then again, if there were, what would you do with all that extra time?
This was first published in July 2002