Concurrent Calls

we have a problem from a branch office, here it is the scenario:

  • Connectivity 2 Mbit/sec dedicated to voip
  • openvpn tunnel to freepbx, tried with and without cipher
  • Freepbx with one cpu xeon x5670 and 2 GB RAM, but TOP says that is used a bit part of them
  • Freepbx behind a vpn server (no-nat) with one hundred Mbit/sec of connectivity

When users try to make more then three calls the voice begins to be choppy.

The bandwidth usage never goes over 400 Kbit/sec
From freepbx shell if i monitor the phones the latency never goes up 50 ms.
From freepbx logs i see sometimes phone disconnected for excessive lag but mtr never shows average latency over 50 ms (even on thouands packets).

Someone can point me on which tool i’ve to use to better check the connectivity or point me somewhere to help me resolve this issue.

Many Thanks

You can install HOMER or VOIPMONITOR to analyse.

Thank you, I’m trying voipmonitor.
Do you have any tips about where to put my eyes on?

thanks again, cheers.

Hi again

You may wish to check out the inline graphs per call and see particularly the calls that were choppy. Lookout for packet loss or high jitter