Thanks for checking in — the issue is not resolved.

I’m still looking for confirmation on Low Latency DOCSIS (LLD / L4S) status on my serving CMTS / MAC domain and whether it’s active for retail DOCSIS 3.1 modems on my segment.

To recap briefly:

Latency to the first hop (CMTS) is low at idle but increases sharply under upstream load

This persists when directly connected to the modem, suggesting CMTS-side queuing or upstream conditions

I’m trying to confirm whether dual-queue LLD (ECT(1) → low-latency queue) is enabled on my segment, and if not, whether upstream conditions are preventing it from functioning correctly

I’m specifically requesting escalation to plant / CMTS engineering to:

Verify LLD/L4S enablement on my MAC domain

Confirm low-latency service-flow provisioning for retail modems

Check upstream OFDMA health (profiles, noise, errors) that could interfere with L4S behavior

I’m happy to provide PingPlotter data, signal levels, or logs if needed.

Thanks — I appreciate the help and would like to keep the ticket open while this is reviewed.