Who this is for: Staff using the Cannon VoIP desktop or mobile app on a computer or phone with a VPN, antivirus, or company security software.

What goes wrong

Calls in the app are choppy, delayed, or have no audio, but desk phones are fine.
Calls work when the VPN is off and fail when it's on.
The app can't connect or keeps reconnecting.

Why it happens

A VPN sends all traffic through a tunnel to another location before it goes to Cannon VoIP. That adds distance and delay, and some VPNs block or slow the kind of traffic calls use.

Antivirus and security software can inspect or block call traffic, or keep the app from using the microphone.

How to fix it

Test with the VPN off. If calls are fine, the VPN is the cause.
Ask whoever manages the VPN to set up split tunneling for Cannon VoIP, so call traffic goes straight to us instead of through the tunnel. Exclude *.cannonvoip.com and the ports on the firewall page.
In antivirus or security software, add the Cannon VoIP app to the trusted or allowed list.
If the software has a firewall, allow the Cannon VoIP app to connect out on the network.
Make sure the app is allowed to use the microphone, and on phones, allowed to run in the background and show notifications.
Restart the app.

Notes for common router types

On most VPN apps, split tunneling is under Settings or Advanced, sometimes called app exclusions or bypass.
On most company VPNs, an administrator sets split tunneling in the VPN server's settings.
On most security software, look for Exclusions, Allowed Apps, or Firewall Rules.

How to tell it worked

Calls in the app sound the same with the VPN on and off.
The app stays connected all day.
Run the free Net Checker with the VPN on.

Still having trouble? Contact Cannon VoIP support at 888-973-0515 or support@cannonvoip.com.

More router settings that affect call quality

See all router settings · What makes call quality good or bad