Over the five-plus years that we've been writing this newsletter, there's one theme that we've never wavered on.  Enhanced DSU/CSU products that add traffic analysis and troubleshooting capabilities pay for themselves very quickly.  In fact, we've even argued that they are one of the very few areas where you can almost always justify ripping out existing equipment and doing a wholesale swap-out - even in tough economic times.

A couple of weeks ago, Visual Networks, one of the leading providers of such devices, upped the ante with the announcement of an architecture that makes deployment more flexible.  With its "Visual Uptime Select" strategy, the company is attempting to make it even easier for organizations to deploy its devices at an even more economical price point.

The first part of Visual's strategy is to offer its DSU/CSU device at essentially the same price as an unmanaged DSU/CSU.  With list pricing starting at $1,195 for a T-1 DSU/CSU, the pricing increases to $1,495 list, if you add in both dial backup and drop-and-insert capabilities.

Then you pay separately for the various software modules that you want to activate.  Rather than the prior extensive but expensive all-or-nothing approach, the software modules are now broken down into real-time monitoring, historical (dubbed back-in-time) capabilities, traffic capture, and class-of-service.  Each module may be purchased separately.

Perhaps the most intriguing capability in the new software pricing module, though, is what Visual refers to as a "by-the-drink" capability.  With this option, Visual is implementing a token-based model whereby users will be able to buy a per-use software capability for a timeframe of perhaps one week.  Under this module, the DSU/CSU will have been collecting stats (for back-in-time analysis) all along, but the software simply will not be enabled for viewing this information.  A problem occurs, you purchase the "token" from Visual, and you have the ability to use the enhanced capabilities only while you desperately need them.  In these cash-strapped times, this could definitely be a big winner.

Next time we'll continue this discussion by addressing integrating these capabilities into the router.

Steve Taylor is president of Distributed Networking Associates and publisher/editor-in-chief of Webtorials. Jim Metzler is vice president of Ashton, Metzler & Associates.