VQM (voice/video quality monitoring) is an advanced monitoring methodology used to mitigate and resolve performance-affecting issues before they become catastrophic. VQM works by leveraging both active (synthetic) and passive (live call/session) testing and analysis. With typical premise-based Unified Communications (UC) implementations, voice and video conferencing application traffic travels over the organizations existing LAN/WAN infrastructure.
As with any other application data, network congestion can delay voice packets or even cause some to be lost along the way. While this is just a minor inconvenience for most data applications – e.g., an email taking slightly longer to process - even a few lost RTP (media) packets can introduce unacceptable echo or disruption in a conversation. End-users have become accustomed to the nearly flawless voice quality and will not settle for lower quality, in spite of the massive cost savings on the back-end provided by UC services.
VQM solves these problems by analyzing live/in-service sessions, taking detailed notes of session state, start & end times, called party and configuration information as well as a robust suite of underlying service-affecting fault details. In addition, synthetic voice traffic generation efforts ensure that service-affecting issues are identified during both on and off-hours, constantly monitoring infrastructure state and reporting on quality. This approach ensures that any underlying issues are caught by the VQM tool, before end-users even notice service degradation.
To break it down into layman’s terms, there are effectively two schools of thought:
Clearly, both approaches are complimentary and provide value, ensuring that any issues that arise are identified immediately. It’s through a combination of these two approaches that Telchemy’s technology tests and analyzes every session, allowing network and application administrators to know if a problem is occurring and its source.
Disruptions in session quality vary in severity and may present themselves as distorted audio and video, cutting in and out, and more. Have you ever had a phone call with a coworker or customer where the quality was so bad that you spent the entire call asking them to repeat themselves? Or a phone call where you don’t hear anything? Or worse, you can hear them, but they can’t hear you?
Problems like these can seriously impact your ability to deliver great customer service. While internal calls are one thing, if end-users or customers have problems calling you, they may just quit calling.
There are three basic categories of performance-related problems that can occur in enterprise IP Telephony:
Network architects and managers need to address call quality and performance management problems during the planning and deployment phases, but should be aware that these problems also occur regularly during normal day-to-day network operation post-deployment.
Many quality-related UC problems are short-lived, temporary in nature, and can occur anywhere along the network path. For example, a user accessing a file from a server or a home-based worker looking at a YouTube video may cause a temporary and brief bottleneck.
This can cause short-term degradation in call quality for other users on the network. Thus, it’s important that network managers use performance management tools, such as those provided by VQM, that are able to detect and measure these types of network impairments.
In addition, the temporary nature of IP delivery issues also means that these problems are not easily detected or easy to reproduce. Problems are not necessarily associated with specific cables or line cards – they can occur randomly due to “collisions” or combinations of several different factors.
Network managers could attempt to use packet loss and jitter metrics to estimate call quality, but this approach is reactive, doesn’t actually correlate to the end-user experience and even more importantly doesn't provide enough diagnostic information alone to actually determine the cause of the problem.
Paessler AG has partnered with Telchemy, the premiere manufacturer of unified communications management solutions, to bring VQM into PRTG Network Monitor. The integration of Telchemy’s SQmediator application-level data makes PRTG even more unique in the industry by not only providing insight into UC application performance, but also into the underlying network infrastructure that is responsible for delivering application traffic in a timely and reliable manner.
Assuming the signaling plane is operational and sessions are established properly, the resulting UC metrics can best be segregated into three classes:
Proper troubleshooting typically follows the following order of operation:
Are you experiencing unified communications quality issues with your current system? Paessler and Telchemy can help. Contact us today to learn more.
iAbout the author: Anthony Caiozzo is a self-starting, perpetually motivated professional with almost three decades of broad experience installing, troubleshooting, building, promoting and selling technical products and services.
Experienced in all stages of the product life cycle, Anthony is familiar with a broad range of telecom and Internet technologies, and in defining win/win partner relationships. Anthony specialized in translating technical jargon and complexity into easy-to-understand content, helping people worldwide learn about the ins and outs of their communications systems and managed services.
When Anthony isn't working hard to promote his team’s achievements at Telchemy, he spends the remainder of his time with his wife, four children, dog, and seven chickens, and restoring his historic New England farmhouse.