VoIP Test

The VoIP test assesses jitter and packet loss for a connection and also provides details on SIP responses, SIP ALG detection, and MOS scores.

Fig 1. VoIP test interface before test start

The MyVoIP test performs jitter and packet loss tests for the connection. The screenshot below also shows the SIP ALG metrics towards the bottom of the results area.

SIP ALG (Application Layer Gateway) is common in many commercial routers. It inspects VoIP traffic and modifies packets if necessary to prevent problems caused by router firewalls. This test detects the presence of SIP ALG. Both upstream and downstream criteria are plotted separately.

Fig 2. Completed VoIP test

The graph tab plots upstream and downstream jitter and packet loss. Use the arrows to the left and right of the graph to switch between the two views.

Fig 3. Graph tab

The RTT (Round Trip Time) tab plots the response times in a bar chart for each packet sent during the test.

Fig 4. RTT tab

The summary tab gives an overview of the VoIP results. Colored circular indicators provide a quick understanding of how the test went.

What is a MOS Score?

The MOS (Mean Opinion Score) is a numeric measure used for VoIP indicating the sound quality at the receiving end of a communication circuit. Although the score is subjective, it provides a widely used method to rate voice quality in a way that is meaningful to end users. The score ranges from 1 to 5, with 5 being the best.

Fig 5. Summary tab