From: Chris Larson (clarson52@comcast.net)
Date: Tue Apr 12 2005 - 09:37:39 GMT-3
You have to take windows tcp window sizing into account. As well as ack'ing
and such. You have to rely or assume the boxes you are using have no config
issues etc. On our oc12 we have to adjust window sizes to get good
increases in throughput. Using tcp based file transfer is a poor way to
measure performance.
...... Original Message .......
On Tue, 12 Apr 2005 12:11:30 +0100 Wayne Bellward <wbellward@gmail.com>
wrote:
>Hi All,
>
>I have two 3550EMI's connected via a 10Mb Full duplex crossover, the
>link is a 802.1q trunk and I only have about four VLANS running. When
>I do an FTP of a 10Mb binary file between two hosts one on each switch
>in different VLANS I get file transfer speeds of about 50KBs. If I
>put the hosts on the same 3550 I get transfer speeds of about 85KBs,
>CEF is enabled but either way I would expect to get transfer speeds
>much greater than those I am getting.
>
>The 3550 has a 8.8Gbps switch fabric and a throughput of 4.4Gbps can
>anyone explain to me why this is happening? I don't think there is a
>problem with the switches or the hosts but get the impression I am
>missing a fundamental aspect of switching.
>
>Many Thanks,
>
>Wayne
>
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Sent from the cell phone of:
Chris Larson CCIE #12380, PMP
Principal Consultant
Superior Technology Networks Inc.
703 577 3303 / 800 746 3556
www.supertechnetworks.com
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