Messages in this thread | | | From | Mike Kilburn <> | Subject | Re: Slow PPP? | Date | Fri, 29 Mar 1996 18:54:48 +0200 |
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> I just tried an experiment to check the throughput (using ftp) between my > host and my ISP. Firstly in Windoze 3.1, and then in Linux (1.3.77). My > modem is a USR Sportster 28.8K internal ISA-bus, connecting to my ISP at > 28.8k (serial port set spd_vhi, 115,200 baud, h/w handshake) > > 100Kb test file Winsock ppp-2.2.0e > ----------------------------------------------------------------- > /pub/test/emptyfile (compressible) 6.24 Kb/s 3.80 Kb/s (-40%) > /pub/test/fullfile (non-compressible) 3.11 Kb/s 2.80 Kb/s (-10%) > > I use the same box booted into Dos or Linux, so there are no hardware > changes, and the transfers were done <10 minutes apart to avoid changes at > the ISP's end where possible. >
How did you do the timing? You should time from the first byte to the last byte received *on the receive side*. Buffering differences can lead to vastly different results when viewed from the transmit side, and unless your using the *exact* same program (not possible if its with 2 OS ) you can get different results. The fact that you got exactly 3.80 Kb/s on a highly compress able file with a link of 28.8 tells me there could be a port fixed at 38.4 somewhere in the stream. Here are some other things to consider:
1. Can you be sure that you ISP has *all* their TS ports at 115200? Maybe you got a 38.4 port when you dialed with linux.
2. Can you be sure the Linux box is at 115200?
3. Can you verify the asyncmap used when dialing with Linux is the same as Windows. This can make a big difference when comparing thruput.
4. Can you check if options like V.J header compression are the same.
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