Looking for help from the official team — phone support has not been able to resolve this and I believe my modem is being misprovisioned for the tier I'm paying for.
The setup
- Plan: Gigabit x2 (2 Gbps down)
- Modem: Hitron CODA56, customer-owned, on Comcast's approved device list, DOCSIS 3.1 capable
- Firmware: 7.3.5.3.2b1
- Location: Lafayette, CA
- CM MAC: (available via DM)
The problem My CODA56 is provisioning with DOCSIS 3.0 channels only — 32 SC-QAM downstream and 4 ATDMA upstream. Zero OFDM downstream channels and zero OFDMA upstream channels.
Direct-to-modem speed test at the demarc tops out around 800 Mbps, which is exactly the 32 × SC-QAM ceiling. There is no physical way to deliver 2 Gbps over SC-QAM-only provisioning — the channel math doesn't work. OFDM downstream is required to reach the tier I'm paying for. Diagnostic data from the modem (192.168.100.1)
- Downstream: 32 channels × SC-QAM 256-QAM (Signal: +9.4 to +11.1 dBmV, SNR: 40–43 dB on every channel, Errors: 0 correctables, 0 uncorrectables across all 32 channels)
- Upstream: 4 channels × ATDMA 64-QAM, +44–45 dBmV
- DOCSIS init: all steps Success, BPI authorized, traffic enabled
- Cable plant is clean — this is not a signal or wiring problem
What I've already done
- Multiple modem reboots
- Verified CODA56 is on the Comcast/Xfinity approved devices list
- Direct-to-modem speed test at the demarc to rule out home wiring
- Tier 1 phone support, who reset the modem and confirmed "speeds look fine on our end" — but ~800 Mbps on a 2 Gbps tier is not fine
What I'm asking
- Please verify OFDM/OFDMA availability on my CMTS node.
- If OFDM/OFDMA is available on the node, please re-provision my CODA56 with the DOCSIS 3.1 channels required to deliver the Gigabit x2 tier I'm paying for.
- If OFDM/OFDMA is NOT available on my node, please confirm that in writing — I'd like a clear answer on whether my address can physically support the tier I'm being billed for.
Happy to provide account number, full name, service address, and CM MAC via DM. Thanks for any help.
Also, your online payment https://payments.xfinity.com is not working:
- can't add card
- can't make one time payment