Current-Users archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: disabling mediaopts for if_wm(4)

On Tue, 9 May 2017, David Young wrote:

On Wed, May 10, 2017 at 09:35:44AM +0800, Paul Goyette wrote:
Well, I got a little bit of a problem...

My new fiber-to-the-home router only has one RJ45 port available, so
I had to get a switch to connect all of the hard-wired network
devices. It all seems to work, except for one problem...

In the uplink direction, I can only push about 3.5Mb/sec, compared
to the expected 50Mb/sec in the download direction.  And, if I
directly connect to the router's RJ45 port I can also get 50Mb/sec
upload speed.

So, the upload problem happens only with the switch.

ISTR that wm(4) has one or more bugs concerning flow control.  It's
possible that when flow control is negotiated, the MAC is not set up to
respect flow control signals, so it keeps sends frames to the peer after
it is asked to pause.  With all buffers full, the peer drops the frames
on the floor.  This would be an important bug to fix.

Does your switch tell how many frames are dropped?

The switch doesn't tell anything! :) It's a real el-cheapo - US$15, purchased locally here in the Philppines. (And I've seen adverts for even less, US$12!)

FWIW, this is a D-Link DEC-1008A 8-port 10/100 with auto-MDI/MDIX.

| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:          |
| (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee dot com   |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd dot org |

Home | Main Index | Thread Index | Old Index