Messages in this thread | | | From | Terry Dawson <> | Subject | Slip/PPP slow, lsz/lrz and minicom slow too. | Date | Wed, 10 Apr 1996 09:58:23 +1000 (EST) |
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I've been simultaneously following the various PPP/Slip slow problems and assisting a friend of mine diagnose just this problem. I don't experience the problem at all.
My friend uses a twin port serial card that purports to be based on 16550AFN uarts and a V.34 modem with a DTE speed of 38k4bps. The modem reliably connects at 28k8bps to his ISP. Using Win95 he routinely achieves ftp put and get transfer rates that are close to expected values. While using Linux kernels 1.2.13, 1.3.77 and now 1.3.85 he achieves something that very nearly approximates 19k2bps. The 19k2bps is consistently repeatable. I've double checked that he is indeed achieving a DTE speed of 38k4bps.
Interestingly, on a punt, we tried a simple terminal connection and used lsz/lrz to test transfers in either direction. These too peg out at just below 19k2bps. Again, a similar test under Win95 gives results much closer to what would be expected for the hardware configuration.
It seems likely to me that the problem my friend is experiencing has little or nothing to do with the tcp/ip networking code, but rather something more closely akin to the serial driver code.
We are still working on further isolating the problem but are rapidly running out of ideas. Is it possible that there is some problem with support of some breeds of 16550 uarts ? We haven't yet tried swappping the serial card, that will be my next suggestion for him.
Terry
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