Who this is for: Offices whose calls get laggy or choppy when the connection is busy, even with a fast plan.

What goes wrong

Delay on calls, so people talk over each other.
Audio breaks up whenever someone uploads a large file, joins a video call, or a backup runs.
The internet feels slow to respond even though speed tests look fine.

Why it happens

Routers hold extra packets in a waiting area (a buffer) when the connection is full. Big buffers mean voice packets sit in line for a long time.

That waiting time is called bufferbloat. It doesn't show on a normal speed test, but it adds delay and choppiness to calls.

Test for it. Run a speed test that reports "latency under load" or a bufferbloat grade. If the delay jumps by more than about 30 milliseconds during the test, you have bufferbloat.
Sign in to your router and look for SQM, Smart Queue Management, Smart Queue, Adaptive QoS, or a setting named after a queue type such as fq_codel or CAKE.
Turn it on.
Set the upload and download speeds to about 85 to 90 percent of your real tested speeds. This is the most important step. Too high and it does nothing; a little low is fine.
Save and run the test again.

On many newer home and small office routers, this is called Smart Queue, Adaptive QoS or Traffic Optimization, under Advanced or QoS.
On most business firewalls, look in Traffic Shaping or QoS for a queue type option and choose a smart or fair queue. Some firewalls call this "fq_codel".
If your router has no option for this, a router that supports SQM fixes it for good. It's one of the biggest call quality improvements for a busy office.

The latency under load result stays within about 30 milliseconds of the idle result.
Calls stay clear while a large upload or download runs.
Run the free Net Checker during a busy time.

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