A month ago Comcast upgraded my head-end for DOCSIS 3.0. I had some backwards compatibility problems so Comcast gave me a new DOCSIS 3.0 cable modem. My problems went away and my bandwidth increased dramatically.
I must say that I am getting quite use to the extra bandwidth. Windows 7 download in only a few minutes, and I enjoy the quicker upload speeds for posting pictures and blog posts. The 3 Mbit/s upload is pretty consistent in my neighborhood. The only time I wish I had more upstream bandwidth is when I am moving large PowerPoint files or synchronizing to the cloud.
Having this much bandwidth exposes two deficiencies. The first deficiency is that my home network can now be a bottleneck. I have one 10 Mbit/s device, 2-100 Mbit/s device, a 1 GigE device with a 802.11g/n network. My machine-to-machine transfer rate tops out at 20 Mbit/s. The second deficiency is latency. It takes 27 ms to go round-trip to local Comcast servers. The latency to some of the SBC approaches 100 ms which introduces echo into my VoIP calls.
I can fix the first problem by buying a new Ethernet swtich and more GigE devices. After all it is only money. The second problem is not something that I can fix because after all this is a best-effort service.
I am delighted that all of the computers and game consoles in the house has enough bandwidth to do what they want, but our phone calls still suffer from echo. I would really like to see Comcast offer different classes of service for their High Speed Internet.