Poor call quality – preliminary tests

Today, 80% of calls travel via VoIP and on data lines.

If disturbed calls are detected in your VOIspeed switchboard, it is necessary to understand if the cause is to be found in your LAN network, in the hardware devices or in the connectivity.

To understand the origin of the malfunction, it is possible to carry out a test by making a call between 2 extensions while, through an ADSL test, the network is overloaded.

Test procedure

  1. Change the switchboard settings:
    • From the VOIspeed configurator choose “Configuration> Company;
    • In “Company management” move to the “Settings” tab
    • Click on the icon and change the settings as follows:
      • P2P enabled: NO
      • Band / quality ratio: higher audio quality (higher bandwidth usage)
  2.  Start a call between two switchboard extensions (possibly not present in the same room);
  3. Start a speedtest (eg speedtest.net) on a PC that uses the same connectivity used for telephony.

During the speedtest, the audio quality must not suffer drops, it must not decay appreciably, you must not hear holes and the latency must not change.

If, on the other hand, the ADSL test significantly worsens the latency of the voice traffic, the priority for UDP traffic towards the UCloud PBX (traffic shaping, QoS…) must necessarily be set on your firewalls.

It is important to note in which phase of the speed test (upload, download, both) any decay is warned, to set queue management in the respective interfaces of the router / firewall.