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расширенные общие приложения (CAKE) (Common Applications Kept Enhanced (CAKE))

ROUND TRIP TIME PARAMETERS

Active Queue Management (AQM) consists of embedding congestion signals in the packet flow, which receivers use to instruct senders to slow down when the queue is persistently occupied. CAKE uses ECN signalling when available, and packet drops otherwise, according to a combination of the Codel and BLUE AQM algorithms called COBALT.

Very short latencies require a very rapid AQM response to adequately control latency. However, such a rapid response tends to impair throughput when the actual RTT is relatively long. CAKE allows specifying the RTT it assumes for tuning various parameters. Actual RTTs within an order of magnitude of this will generally work well for both throughput and latency management.

At the 'lan' setting and below, the time constants are similar in magnitude to the jitter in the Linux kernel itself, so congestion might be signalled prematurely. The flows will then become sparse and total throughput reduced, leaving little or no back-pressure for the fairness logic to work against. Use the "metro" setting for local lans unless you have a custom kernel.

rtt TIME Manually specify an RTT.

datacentre For extremely high-performance 10GigE+ networks only. Equivalent to rtt 100us.

lan For pure Ethernet (not Wi-Fi) networks, at home or in the office. Don't use this when shaping for an Internet access link. Equivalent to rtt 1ms.

metro For traffic mostly within a single city. Equivalent to rtt 10ms.

regional For traffic mostly within a European-sized country. Equivalent to rtt 30ms.

internet (default) This is suitable for most Internet traffic. Equivalent to rtt 100ms.

oceanic For Internet traffic with generally above-average latency, such as that suffered by Australasian residents. Equivalent to rtt 300ms.

satellite For traffic via geostationary satellites. Equivalent to rtt 1000ms.

interplanetary So named because Jupiter is about 1 light-hour from Earth. Use this to (almost) completely disable AQM actions. Equivalent to rtt 3600s.