Getting your VOIP tuned up for multiple devices that need a priority boost can be tricky. My understanding is imperfect, but it all works reliably for months now, and the above diagram helps lay out the configuration I'm using.
How do I make sure my own upstream activities, such as uploading this large YouTube video (100 minute 720p how-to), don't degrade the gamer's crucial upstream bandwidth? How can I also be sure that my VOIP call quality is maintained on my 2 Ooma Telo (VOIP telephone) devices? Well, to start, it helps that I have a fat pipe, courtesy of Cox.
I don't want my whole household to rely upon the reliability and QoS of my VOIP device (as I used to do with a Vonage V-Portal, with unreliable results). I would rather have one less point of failure, and have the router connected straight to my cablemodem anyway. Since I have 2 Oomas, it's really the only choice that makes sense for me, seen pictured above.
But really the important step is to enable a powerful router's QoS, and manually tune it. This is partially explained by Ooma here, which has great diagrams, and this key sentence:
For the most optimum results, it is best to configure your "Upstream Internet Speed" to be 15-20% less than your measured upstream bandwidth.
And this key sentence, from this stream tuning article:
When determining your bitrate, a good rule of thumb is to leave about 25% of your upstream unused. If you have a 2mbps upload speed, set your stream bitrate to 1500kbps. This leaves enough room for the occasional burst of data from the codec as well as for background applications such as any VoIP software and of course SC2 itself.
What you'll see me demonstrate in the video is that when you turn on QoS and leave upstream bandwidth at auto, it throttles the upstream bandwidth far too much, a common trait, affecting numerous router brands, apparently. I settled at manually setting it to 7Mbps, which resulted in actual max overall upload speeds of around 5Mbps, leaving me 2Mbps of lee-way to not notice bad days where congestion may drag me down to 5Mbps upstream, period. This gives me a consistent experience, no matter how bad the internet congestion gets.
It might not be the right way to do it, but it works for me, with my stable hardware combination. Consistency and stability trump raw speed, and really matters for gamers and sysadmins alike, makes for a happier household.