FASTline II Problems

Wolfgang Walter wolfgang.walter@stusta.mhn.de
Thu Feb 3 19:18:11 2000


On Thu, Feb 03, 2000 at 08:08:01AM +0100, Guenther Fischer wrote:
> Hi,
> we use some FASTline-II-PCI-UP (10/100MBit,fullduplex) mostly conected to
> Cisco switches.
> Now I see some magic values in throuput. In one direction 10 MB and in the
> other only 200-400 KB. The switch says fullduplex and the card too. We
> tried to set the parameters on switch and card directly but I deon't see
> better values. I got the values with netio and also ind the same dimension

Do you transfer from a 10Mbit-port to a 100Mbit-port? Then I asume that
transfering from 10mbit to 100mbit is fast, the other way slow?

The reason is that if the sender sends packets faster then the receiver can
handle them they fill the switch's buffers. Then it will start dropping them.

Now TCP should handle this. For some reasons it behaves rather bad in this
situation.

If both machines are connected to the same switch you can use ethernet flow
control ieee 802.3x in duplex mode (if the card and the switch supports it - I
think tulip-chips do not) or half-duplex back pressure in half-duplex mode.

Which Cisco switch do you use? The workgroup switches most often do not
support symmetric flow control (they do not send pause frames). And
half-duplex back pressure is usually deactivated.

So you may try to use 100Mbit half-duplex and active it for your 100MBit port.

At least with 3com switches, this is a workaround.

> with ftp.
> Is there a newer driver - the last I see was 91g from 7/99. 
> 
> I use redhat 6.0 with tulip 91g. 
> -- 
> 	~Guenther Fischer
> 
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Wolfgang Walter

-- 
Veni, Vidi, VISA:
	I came, I saw, I did a little shopping.

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