Measuring UC/Video Quality with Network Observer
If you’re implementing videoconferencing, it’s important to know what metrics to monitor to ensure high quality videoconference calls. First, let’s look at the key metrics for managing unified communications apps.
Mean Opinion Score (MOS): Starting with a theoretical perfect score of 5 (excellent), impairment factors such as codec, delay, jitter, and packet loss are used to calculate how a typical user would rate voice quality.
QoS: helps verify that precedence settings are the same for all components of the call or videoconference
Packet loss: the percentage of packets that did not reach their destination. Consult the vendor to understand maximum packet loss the solution can sustain before quality is impacted.
Jitter: measures the variability of delay in packet arrival times
Delay: The amount of time it takes a packet to reach its destination. Whenever packets travel a network, some delay is inevitable. Consult the vendor for maximum delay allowed before call quality is impacted.
Next, let’s explore where you’d find these metrics in Observer.
From the main Observer screen, open the capture containing the relevant conversation, and click the Expert Analysis tab at the bottom of the screen. Select the VoIP Events icon on the left side of the screen. VoIP Events provides multiple ways to analyze conversations in aggregate or on a per-call basis. Let’s explore the tabs within VoIP Events.
VoIP Summary: provides key metric averages for all conversations contained in the capture
Calls Tab: shows each video or VoIP conversation for more granular investigation. Right-click in the column of any metric you do not understand and select Expert Explanation for a definition.
RTP/PTCP Graph: graphs jitter and lost packets over the time of a call
Expert VoIP Settings: configures metrics, graphs, and alarms within VoIP Events
With a basic understanding of key metrics and the technical specifications from your videoconferencing solution, you can set thresholds and alarms for supported codecs in Observer to notify you of potential issues before they impact the user.