Re: Odd TCP snd_cwnd behaviour, resulting in pathetic throughput?

[mlelstv%serpens.de@localhost (Michael van Elst)]

stix%stix.id.au@localhost (Paul Ripke) writes:

>I've recently been trying to get duplicity running for backups of my
>main home server, out to the magical cloud (aws s3 to wasabi.com).

>I have discovered that bandwidth oscillates in a sawtooth fashion,
>ramping up from near nothing, to saturate my uplink (somewhere around
>20-30Mbit/s), then I get a dropped packet, and it drops to near nothing
>and repeats, each cycle taking around a minute.


That could be someone doing bandwidth shaping on the connection.

If ALTQ is working (means: you need to bump HZ for modern network speeds),
you could try to throttle outgoing data with CBQ to see if the pattern
goes away.