It seems if both clients are having bidirectional traffic, dual-
{dst,src}host has the same effect as triple-isolate (on both lan and
wan interfaces) on their bandwidth.
This shouldn't happen though, or am I wrong?On Wed, 2019-01-02 at 22:57 -0500, Georgios Amanakis wrote: > I can reproduce this one to my surprise, too. > I tested on my Comcast connection, with a WRT1900ACS, running openwrt > (r8082-95b3f8ec8d, 4.14.70), with two interfaces br-lan and > eth0(wan). > > IP1=1 up / 8 down IP2=4 up / 4 down > src/dst, bidir: IP1=0.88 / 8.44, IP2=0.66 / 7.75 (ok) > dualsrc/dualdst, bidir: IP1=0.27 / 10.56, IP2=1.41 / 6.42 (unfair) > > No VLANs, no other schedulers on eth0 and br-lan apart from cake. > > > > On Wed, 2019-01-02 at 00:04 +0100, Pete Heist wrote: > > In my one-armed router setup I’m seeing host fairness work > > perfectly > > with srchost or dsthost, but with dual-srchost or dual-dsthost, > > host > > fairness deviates from the ideal, _only_ when there's bi- > > directional > > traffic. The deviation is then dependent on the number of flows. Is > > this expected? > > > > I had thought that dual-src/dsthost worked the same as src/dsthost > > (fairness between hosts) with the exception that there is also > > fairness of flows within each host. > > > > Here are some results (all rates aggregate throughput in Mbit): > > > > IP1=8 up / 1 down IP2=1 up / 8 down (post-test tc stats > > attached): > > srchost/dsthost, upload only: IP1=48.1, IP2=47.9 (OK) > > srchost/dsthost, download only: IP1=47.8, IP2=47.8 (OK) > > srchost/dsthost, bi-directional: IP1=47.5 up / 43.9 down, > > IP2=44.7 up / 46.7 down (OK) > > > > dual-srchost/dual-dsthost, upload only: IP1=48.1, > > IP2=48.0 (OK) > > dual-srchost/dual-dsthost, download only: IP1=47.9, > > IP2=47.9 (OK) > > dual-srchost/dual-dsthost, bi-directional: IP1=83.0 up / 10.7 > > down, IP2=10.6 up / 83.0 down (*** asymmetric ***) > > > > Dual-srchost/dual-dsthost, bi-directional tests with different flow > > counts: > > > > IP1=4 up / 1 down IP2=1 up / 4 down: > > IP1=74.8 up / 18.8 down, IP2=18.8 up / 74.8 down > > > > IP1=2 up / 1 down IP2=1 up / 2 down: > > IP1=62.4 up / 31.3 down, IP2=31.3 up / 62.4 down > > > > IP1=4 up / 1 down IP2=1 up / 8 down: > > IP1=81.8 up / 11.5 down, IP2=17.4 up / 76.3 down > > > > IP1=2 up / 1 down IP2=1 up / 8 down: > > IP1=79.9 up / 13.5 down, IP2=25.7 up / 68.1 down > > > > The setup: > > > > apu2a (kernel 4.9) <— default VLAN —> apu1a (kernel > > 3.16.7) <— VLAN 3300 —> apu2b (kernel 4.9) > > > > - apu1a is the router, and has cake only on egress of both eth0 and > > eth0.3300, rate limited to 100mbit for both > > - it has no trouble shaping at 100mbit up and down simultaneously, > > so > > that should not be a problem > > - the same problem occurs at 25mbit or 50mbit) > > - since apu2a is the client [dual-]dsthost is used on eth0 and > > [dual- > > ]srchost is used on eth0.3300 > > - the fairness test setup seems correct, based on the results of > > most > > of the tests, at least. > > - note in the qdisc stats attached there is a prio qdisc on eth0 > > for > > filtering out VLAN traffic so it isn’t shaped twice > > - I also get the exact same results with an htb or hfsc hierarchy > > on > > eth0 instead of adding a qdisc to eth0.3300 > > - printk’s in sch_cake.c shows values of flow_mode, srchost_hash > > and > > dsthost_hash as expected > > - I also see it going into allocate_src and allocate_dst as > > expected, > > and later ending up in found_src and found_dst > > > > I’m stumped. I know I’ve tested fairness of dual-src/dsthost > > before, > > but that was from the egress of client and server, and it was on a > > recent kernel. Time to sleep on it... > > > > _______________________________________________ > > Cake mailing list > > [email protected] > > https://lists.bufferbloat.net/listinfo/cake _______________________________________________ Cake mailing list [email protected] https://lists.bufferbloat.net/listinfo/cake
