Assessing LEDBAT´s Delay Impact

The major goal of the LEDBAT congestion control mechanism is to limit the amount of queuing delay that it causes. Using simulations, we show two aspects of the mechanism that may sometimes make LEDBAT\´s delay impact quite significant: first, it updates its "base delay" every 10 minutes, but may measure its own induced delay in doing so, even in the presence of significant transmission jitter. This may lead to a continuous growth of the fixed delay that a LEDBAT flow produces if it runs for long enough. Second, it requires competing traffic to be long-lived and greedy for it to reduce its rate accordingly, however, such traffic is in general not latency-critical.