The tide is turning on how enterprises deliver applications, and the change is making it hard for some IT shops to adapt. The problem is that applications aren’t just about transactions anymore: They have far-reaching consequences of delivering content across a wide swath of Internet and local network infrastructure. Monitoring that infrastructure with tools of the past isn’t easy, as these tools tend to focus on a single area or layer in the protocol stack.

Complicating things is the fact that keeping your applications infrastructure running smoothly and delivering the best possible overall performance for your users can require installing multiple products, such as WAN application accelerators, reverse proxy servers, bandwidth monitors and load balancers. Having staff with the skills necessary to maintain these products—and to understand when they have intermittent failures or experience congestion—is a challenge.

“As more services—particularly real-time communications applications—are delivered across the network infrastructure, it’s critically important to monitor and manage the overall performance of the network,” says Sherrie Littlejohn, executive vice president of Network Services & Operations at Wells Fargo in San Francisco. This may mean more work in terms of what to monitor. “In addition to network latency, we measure jitter, packet drop and other performance characteristics,” she says.

As firms deliver complex applications that involve Web servers, distributed databases and other Web 2.0 devices, the situation is going to get even more complex because parts of this infrastructure lie outside the traditional IT sphere of control.

“Although we do trend analysis on our network’s utilization, we like to check on our network during shift changes or on Mondays because that’s when our call volumes are highest,” says Bart Waress, the IT director at Home Buyers Warranty in Denver. He uses monitoring tools from Cisco and Qwest to keep track of end-to-end performance.

“We haven’t had to upgrade our bandwidth since the move to MPLS [Multiprotocol Label Switching] two years ago,” he says, “even with the increasing use of cloud-based applications such as Salesforce.com and the move to online customer care. Given the state of the economy, I would rather spend $40,000 to upgrade our applications than buy a load balancer right now.”