Home networking: How to avoid traffic jams

Now let's dive into the rest of your router's quality-of-service settings.

WMM should be enabled by default. To double-check on the DIR-655, click Advanced in the horizontal menu bar, Advanced Wireless in the vertical menu, and place a checkmark next to WMM Enable. Click Save Settings to preserve any changes.

While still in the Advanced tab in the horizontal menu bar, click QOS Engine in the vertical menu bar. In the box labeled WAN Traffic Shaping, place checkmarks next to the Enable Traffic Shaping and Automatic Uplink Speed settings. The router will automatically measure the maximum speed that your ISP will allow you to upload data to the Internet and restrict outbound traffic so that it doesn't try to exceed that limit and create unnecessary contention.

Note that if your ISP is a cable company, such as Comcast, there's a chance Automatic Uplink Speed will report an inflated uplink speed because these services throttle down their uplink speeds after an initial burst. If you experience poor VoIP performance, you might need to disable Automatic Uplink Speed and enter a speed manually.

(Typical DSL uplink speeds range from 128 to 768Kbit/sec., depending on the level of service you're paying for and your distance from the phone company's central office. Cable Internet uplink speeds average about 2Mbit/sec., while fiber services such as Verizon's FiOS can top out at speeds as high as 20Mbits/sec. You can measure your download and uplink speeds using a free online bandwidth meter such as Speakeasy's Speed Test.)

In the box labeled QOS Engine Setup, place checkmarks next to Enable QoS Engine, Automatic Classification and Dynamic Fragmentation. If you have a slow uplink speed (e.g., less than 512Kbit/sec.), enabling Dynamic Fragmentation configures the router to break up large packets into smaller ones for smoother performance.