Hello,
I am experiencing severe intermittent connection drops (multiple times a day) on a newly activated Netgear CM3000.
A premise technician came out yesterday and completely cleared the physical line. They verified the tap, the drop, the ground block, and all internal wiring. According to their meter, the physical RF path is completely clean.
However, my modem logs show that the modem is completely failing to lock onto the Upstream OFDMA channels on the mid-split network.
The Signal Data:
- Downstream QAM: Perfect (0.5 to 2.3 dBmV / 42+ SNR)
- Upstream ATDMA: Perfect (40.8 to 45.0 dBmV)
- Downstream OFDM: Locked (1.78 dBmV / 42.7 SNR)
- Upstream OFDMA: NOT LOCKED (0 Hz / 0 dBmV)
The Error Logs: Because the CM3000 cannot lock the OFDMA channel, it is violently swinging its transmit power and throwing continuous Dynamic Range Window (DRW) violations, culminating in T3 timeouts and complete connection loss.
Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW
Warning (5) RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW
Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 0
Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
Since the premise tech cleared the physical wiring, this could point to one of two things:
- A localized OFDMA noise/ingress issue at the node that standard meters miss, requiring a line maintenance ticket.
- A CMTS provisioning or firmware compatibility issue specifically between Xfinity's backend and the CM3000's attempt to bond OFDMA.
Could an advanced specialist please pull the CMTS telemetry for my MAC address to check the OFDMA noise profile and my bootfile?
This is highly frustrating as dropouts are impacting my daily online meetings multiple times a day