From: Sven Eckelmann <sven@narfation.org>
To: b.a.t.m.a.n@lists.open-mesh.org
Cc: Marek Lindner <mareklindner@neomailbox.ch>
Subject: Re: [B.A.T.M.A.N.] [PATCH v5 0/7] B.A.T.M.A.N. V - fallback to tp meter estimation if throughput otherwise not available
Date: Mon, 25 Nov 2019 09:41:52 +0100 [thread overview]
Message-ID: <1733664.4DtWKhy3NH@sven-edge> (raw)
In-Reply-To: <8046301.0ldSNLAhfO@sven-edge>
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On Saturday, 8 September 2018 19:38:01 CET Sven Eckelmann wrote:
[... explanation why this test could create problems for other wifi connections...]
> Is there anything which I missed that could ease my mind?
Beside this potential problem, there is also the problem of the interaction
with the ethtool throughput gathering (brought up by Matthias Schiffer [1]
and Matthias Fritzsche [2]). The ethtool code basically prevents the correct
measurement in many situations. I will try to summarize it now:
* ethtool's link_ksettings is not about speed towards a neighbor behind the
interface but about either
- PHY layer speed class from local ethernet port to next peer (for direct
connections)
- connection towards next (internal) switch
- propagated value from a lower layer device (e.g for vxlan)
- "random" value (e.g. tun/tap)
- ...
* often connections indirect (switches, VPN, WiFi bridges, L2 firewalls, ...)
* B.A.T.M.A.N. V requires a measurement for the throughput towards a neighbor
and not the maximum(?) PHY layer speed of the first hop over the current
medium
The proposed solution is to drop the ethtool link_ksettings usage when the
tpmeter (or similar) approach for neighbor speed measurements is integrated.
Kind regards,
Sven
[1] https://github.com/freifunk-gluon/gluon/pull/1872#issuecomment-55767698
[2] https://patchwork.open-mesh.org/patch/17371/#31059
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prev parent reply other threads:[~2019-11-25 8:41 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-07 9:59 [B.A.T.M.A.N.] [PATCH v5 0/7] B.A.T.M.A.N. V - fallback to tp meter estimation if throughput otherwise not available Marek Lindner
2018-09-07 9:59 ` [B.A.T.M.A.N.] [PATCH v5 1/7] batman-adv: tp_meter - prevent concurrent tp_meter sessions by using workqueue Marek Lindner
2018-09-07 9:59 ` [B.A.T.M.A.N.] [PATCH v5 2/7] batman-adv: tp_meter - don't check for existing session Marek Lindner
2018-09-07 9:59 ` [B.A.T.M.A.N.] [PATCH v5 3/7] batman-adv: tp_meter - allow up to 10 queued sessions Marek Lindner
2018-09-07 9:59 ` [B.A.T.M.A.N.] [PATCH v5 4/7] batman-adv: tp_meter - add caller distinction Marek Lindner
2018-09-07 9:59 ` [B.A.T.M.A.N.] [PATCH v5 5/7] batman-adv: tp_meter - add option to perform one-hop test Marek Lindner
2018-09-07 9:59 ` [B.A.T.M.A.N.] [PATCH v5 6/7] batman-adv: ELP - use tp meter to estimate the throughput if otherwise not available Marek Lindner
2018-09-08 17:11 ` Sven Eckelmann
2018-09-07 9:59 ` [B.A.T.M.A.N.] [PATCH v5 7/7] batman-adv: ELP - add throughput meter test duration attribute Marek Lindner
2018-09-08 17:38 ` [B.A.T.M.A.N.] [PATCH v5 0/7] B.A.T.M.A.N. V - fallback to tp meter estimation if throughput otherwise not available Sven Eckelmann
2019-11-25 8:41 ` Sven Eckelmann [this message]
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