When multiple ISPs called us the same week about unexplained upstream congestion, we expected a peering issue. Instead, NetSense Flow revealed thousands of compromised subscriber devices launching coordinated outbound UDP floods toward Chinese ASNs. This is the story of how we diagnosed it — and why most ISP playbooks fail when the DDoS is coming from inside the network.
When a subscriber loses internet, the root cause is often an ONU going offline—but diagnosing why can take time if operators rely only on OLT CLI and scattered tools. In this guide, we walk through practical techniques for troubleshooting ONU outages in GPON networks, including how to identify power loss, optical faults, partial PON failures, and signal degradation using historical telemetry and network observability. Learn how ISPs can reduce troubleshooting time and quickly pinpoint whether the issue is a single customer, failing fiber, or a larger access network problem.
Frequent fiber outages can cost thousands per minute. Discover seven proven tactics-from AI-driven predictive maintenance to PON-level redundancy and automated TR-069 remediation-that keep FTTH networks online and customers happy.
