Messages in this thread | | | Date | Wed, 17 Apr 1996 09:44:58 -0400 | From | Robert L Krawitz <> | Subject | Re: Linux-1.3.89 |
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cc: linux-kernel@vger.rutgers.edu Date: Tue, 16 Apr 1996 22:46:21 -0400 From: "Eric Schenk" <schenk@cs.toronto.edu>
Robert L Krawitz <rlk@tiac.net> writes: >FTP performance to a solaris host over PPP (28.8 connection) is still >slow -- 2.6 KB/sec for uncompressible, 10+ for perfectly >compressible. Grabbing something from tsx-11 (which is much further >away), I got 3.1 for a .gz file.
The problem here is on the Solaris end of things. It's just a bit to anxious to retransmit things. The main problems seem to be in the algorithm for estimating round trip times, and in the algorithm to do slow startup on a TCP link. You can help your performance a bit by picking a smaller value for MRU on your PPP link. I find performance on a 14.4k link gets acceptable with an MRU of 552. I'd be interested to hear what happens with a 28.8 connection. Note that you still need to transfer at least 60k or so of data before the cost of the unneeded retransmits starts to be swamped by the amount of data you are sending.
My PPP connection is actually to a Cisco 2509 router on the same ethernet as the Solaris host. I can't change the MRU due to a bug in the Cisco firmware.
-- Robert Krawitz <rlk@tiac.net> http://www.tiac.net/users/rlk/
Member of the League for Programming Freedom -- mail lpf@uunet.uu.net Tall Clubs International -- tci-request@aptinc.com or 1-800-521-2512
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