Jitter Issues with VOIP

[DavidCameron]

Hi everyone,

Has anyone dealt with significant jitter problems? I have a couple of users experiencing such bad VOIP performance that we've had to switch them to Ethernet for now. Their speed tests always show a jitter of 50-60 ms. 

We're all using the same WiFi adapter with the same driver version, running the same version of Windows, and connected to the same network and access point. Network traffic isn't particularly high at the moment. We have two 1Gbps internet lines connected to two MX devices. Since my connection isn’t affected, I doubt it’s a network-wide issue.   compassmobiletree

The high jitter persists regardless of their location within the building, so I don't think it's related to their local access point (I rebooted it just to be sure).

Any suggestions will be appreciated

Thanks in advance

[DarrenOC]

Hi @DavidCameron , what’s your telephony solution?  Is it on-prem or cloud based?  How are you prioritising voice traffic?

[PhilipDAth]

Are these softphone users on a notebook?
Is it more pronounced when the notebook is using battery, or the battery is below a certain % level?

If had had issues with WiFi drivers going into PSP mode to save power.  In PSP mode the AP is required to hold or buffer the packets and the client polls the AP to get the packets when it wants them.  This allows the client to save power, by powering down its WiFi NIC in between polls.

The below commands configure the driver to operate in CAM mode (constantly awake), and the AP is allowed to send a packet as soon as it is has one.

powercfg /SETDCVALUEINDEX SCHEME_CURRENT 19cbb8fa-5279-450e-9fac-8a3d5fedd0c1 12bbebe6-58d6-4636-95bb-3217ef867c1a 0
powercfg /SETACVALUEINDEX SCHEME_CURRENT 19cbb8fa-5279-450e-9fac-8a3d5fedd0c1 12bbebe6-58d6-4636-95bb-3217ef867c1a 0