There are a lot of terms floating around to describe how to set up metrics for evaluating service performance over the network. The best established is Quality of Service, or QoS, which has generally taken on a fairly technical, bandwidth-centric definition where it remains valuable as a metric, but is far from summing up what really counts in the eyes of the end user.

There are other terms like RUM or "real user monitoring" that are technical, but which do at least focus on a series of monitoring technologies truly targeted at the "real user" or "end user."

And then there's QoE, or Quality of Experience, which is my personal favourite because it is not centred in technology, but in the flesh-and-blood experience of the user consuming your services.

This focus is a lot like the original Mean Opinion Score (MOS), as it applied to telecommunications services. Like it or not, how your customers "feel" about your services is going to be how they're going to vote with their budget approvals.

This isn't to say that technical metrics don't count. You absolutely need them. Building towards QoE with a good combination of technical metrics and a healthy dose of customer dialogue is a fine art.

In this column we're going to look briefly at some of the metrics and technologies that most often apply. But before we do, I suppose I should answer the obvious question for many network managers: "Why me? Why should I care about QoE? Isn't that the job of the applications manager or the helpdesk?"

The answer is that you're partly right. QoE isn't your job alone. But the network is the delivery system for almost all application services, like it or not - including VoIP and unified communications, but most predominantly focusing on web-based applications. Many of these depend heavily on network-centric monitoring tools to ensure their performance.

Data from EMA shows that web-based applications for internal use dominate in terms of what's actually being deployed over the network. They are followed by client-server applications, then web-based applications for external use and web services, and all those are well ahead of VoIP.