Why Quality of Experience matters to network managers
Many metrics for VoIP monitoring and maintenance.
By Dennis Drogseth, Network World | Network World US | Published: 01:00, 07 July 2008
Probably the biggest debate regarding QoE in terms of response time is between the value/role of synthetic versus observed transactions. The truth is that both are valuable. Synthetic tests are proactive, can give you more consistent data suitable for SLA requirements, and can let you know if availability is lost, which observed transactions typically cannot.
Many synthetic tests also offer diagnostic value, especially when the scripts are optimised to look at certain types of transactional behaviours that occur at on an ad hoc basis in the real world. On the other hand, synthetic tests occur at specified intervals and therefore may fail to capture any number of real problems that occur in finite timeframes.
Moreover, many observed capabilities have become increasingly rich in function and are beginning to offer much of the granularity of insight once available only in synthetic tests. So, the truth is that both synthetic and observed should be in place - if you really care about QoE.
Placement is also important. Data-centric transactional monitoring can provide back-office detail that is quite useful in diagnostics, but it can also provide rich insights into issues surrounding QoE - in some cases playing back actual transactions in cinematic manner.
But capturing data at the end station is really at the heart of QoE, through either synthetic and/or observed transaction capabilities. Many of the more network-centric solutions for QoE benchmarking sit at the edge of the data centre and calculate end-user experience, in some cases in conjunction with insights into the back-office transaction as well.
Most of these are not "heavy hitting" in the true QoE sense. Still, their insights can allow you to diagnosing the cause of the problem far more quickly, as well as helping you anticipate performance degradations in remote locations.
Dennis Drogseth is research VP at analyst firm Enterprise Management Associates (EMA).