Upstream OFDMA Causing T3/T4 Timeouts – Need CMTS Provisioning Fix (Netgear CM3000, 2 Gbps Plan)

After countless hours today with several virtual chats, live on the phone support, and “Tier 2” transfers i’m trying this as a last hopeful resort.

Hi Xfinity Support,

I'm having persistent internet drops that appear directly tied to upstream OFDMA instability. I’ve already had a technician visit, and phone support has stated OFDMA was disabled — but my modem logs and status page show otherwise.

---

📦 Setup:

• Modem: Netgear CM3000 (DOCSIS 3.1, Xfinity-approved)

• Plan: 2 Gbps

• Connection: Wired and wireless drops

• Symptoms:

  • Frequent disconnections

  • Event logs full of T3 timeouts, T4 timeouts, and no unicast ranging opportunities

  • Drops correlate with OFDMA Channel locking or flapping

---

Key Log Indicators:

• Started Unicast Maintenance Ranging - No Response received - T3 time-out

• 16 consecutive T3 timeouts

• Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out

• OFDMA Channel 1 = Locked

• OFDMA Channel 2 = Not Locked

• Profile IDs: 12, 13

• Power levels around 37.3 dBmV

---

What I've Tried:

• Power-cycled modem

• Factory reset modem

• Tech visit (confirmed signals look clean)

• Xfinity phone support says they "disabled OFDMA", but modem is still receiving OFDMA provisioning from CMTS

---

Request:

I’m requesting that upstream OFDMA be fully disabled at the CMTS level:

• A new provisioning config file pushed to my modem that excludes OFDMA upstream channels

• Verification that Profiles 12/13 are no longer being assigned

• Confirmation from engineering that the CMTS override is in place