DOCSIS 3.1 Modem not provisioned correctly (DOCSIS 3.0 QAM 256 Channels vs DOCSIS 3.1 / OFDM)
High level issue: Was having internet issues. Comcast support said my old SB6121 "is not supported" and was the issue. Didn't beleive them, but after 10 years of use, I've got my money's worth. Wasn't able to get my full 200Mbps Blast speed anyways. So, I order a new DOCSIS 3.1 modem and got talked into upgrading to the New Gigabit internet plan for a meesly extra $20/month. Too good to be true, right? Right. Consistently getting less than HALF that (high 300s, 400-500Mbps max) even though my signal stats are well within spec. Upstream is pretty rock solid 40+ Mbps, with no lag time. On site tech says everything checks out. Must be an issue with my (new) modem. I think it's an issue with provisioning, though I'm open to a well thought out explaination why I may be wrong.
Details you will ask me about:
Modem - Arris model SB8200 - Hardware version 6
Software version - AB01.01.009.32.01_122319_183.0A.NSH
Direct wired connection. All power levels look good.
32 downstream channels - Locked
Modulation - QAM256
POWER - between -1.7 and +.4 dBmV
SNR/MER - between 39.8 and 41.8 dB
corrected and uncorrectables seem to be all over the place
Had a Comcast tech out to the house. All internal lines look good. Said outside line tests good, except the mouse hanging out in the box and an older cable that's a little long (box to house). He said he "Will talk with someone about replacing it." Don't much trust his expertise, since he didn't know much about public IP provisioning (I have a secondary issue that needs resolved concerning my Comcast security system). Of note, he said my speeds would keep going up if I were to run a longer speed test, so it "looks fine" to him. He also thinks modems don't have IP addresses, and that's only handled by your router. I just said "OK", as I didn't feel like explaining it to him the differnece between Public and private IP's. It was obvious he wouldn't be much help. He said it was my modem and to pick up an XB6 from the comcast store. I'd rather just provision my DOCSIS 3.1 modem appropriately. Something that sticks out to me, I thought you could only get gig speed tier via the DOCSIS 3.1 / OFDM downstream channel, not the other 32 DOCSIS 3.0 QAM 256 channels. Though, my modem lights up blue on the downstream, indicating DOCSIS 3.1.