This has been a couple of interesting couple of weeks. I am paying for Gigabit internet. Well, I had an Arris SB6183 cable Modem. It is a DOCSIS 3.0 16x4, with a 400 Mbps max internet speed. So I decided to upgrade my modem.
My SB6183 was consistently giving me between 450 and 600 Mb/s. So I went out and bought another Arris modem. The first was a used CM8200A DOCSIS 3.1 32X8 modem. Found out later that the modem was returned by the previous owner because it "didn't work." Well, I got it hooked up and provisioned, and it was giving me speeds all over the map. Speedtests were from 200 - 900 Mb/s (mostly the lower end of that), generally far lower than the DOCSYS 3.0 modem.
So I called Comcast back, and reprovisioned the SB6183, and sent it back and got an actual SB8200v3 modem. Provisioned this one, ahd have, over the past 36 hours, had speeds between 180 and 700 Mb/s, with much of it in the 200-400 range, 20-40% of the speed I am supposed to be getting. Everything except the cable modem is the same. from my FreeBSD desktop, through the cabling, two switches, to the firewall and then to the cable modem. I even swapped the cable between the WAN interface on my pfsense box and the cablemodem, just for funsies. Made no difference. And when I put the SB6183 in the circuit, the speeds go back to consistency, and at a higher speed than it should be capable of.
So after about 4 - 5 hours on the phone with comcast in the last 8 days, and a trip into the comcast store, I am getting far less than I am paying for. They have set up a dispatch for this coming week, so we shall see what he finds.