WHAT IS BUFFERBLOAT?
A connection can keep moving lots of data while response time rises sharply under load.
QUEUES CAN ADD DELAY
Network equipment uses queues to hold traffic temporarily. When a link becomes saturated, an oversized or poorly managed queue can keep packets waiting for much longer than they do while the connection is idle. Throughput may still look healthy while interactive traffic feels delayed.
IDLE VS LOADED LATENCY
An idle latency sample describes response time when the test path is not deliberately saturated. Loaded latency samples are taken while download or upload traffic is active. The increase between those conditions is useful evidence of how responsiveness changes under load.
A browser can observe response-time changes during traffic, but it cannot directly inspect every queue inside your router, modem or ISP. A large increase is evidence of load-related latency, not proof of the exact device or queue that caused it.
WHAT USERS NOTICE
Common symptoms include a call becoming delayed when someone starts an upload, game response worsening during a large download, or web interactions feeling sluggish while cloud backup is active. The symptoms can have other causes, so compare repeated idle and loaded measurements before drawing a conclusion.
WAYS TO NARROW THE CAUSE
Repeat the test over Ethernet, pause other heavy traffic, compare download load with upload load and test again after router configuration changes. Some routers provide modern queue-management features; whether they help depends on the actual bottleneck and configuration.
RUN BUFFERBLOAT TEST→Reviewed for technical wording, measurement boundaries and links to the current 0bps toolset.
External references are provided for standards, definitions and deeper technical context. 0bps explanations remain independently written.