Re: ISDN with BitSurfr

Charles Scott (cscott@freeway.net)
Tue, 22 Oct 1996 23:16:26 -0400 (EDT)

Thoth:
You need to be carefull how you test throughput at those speeds. The
turnaround time can start to eat a significant amount of your time
depending on how you're doing the test. You might try to run up a couple
FTP sessions to see what they do in total. I can run up to nearly
15K/sec that way with a Hayes ESP board. The problem is that something
craps out and it comes to a screaming halt after a bit of pushing it that
way. I do need to add memory to our PM2E with the 5BRI card in it but
I've alread updated the BS to j. The other thing I have yet to try is
the Kernel32 patch for Win95, which is what I'm running here at home.
Now, if only I had the time to do all that.

Chuck

On Tue, 22 Oct 1996 thoth@purplefrog.com wrote:

>
> Well, I bought one of those TC-200-S6-1 cards (16650 UART, 460Kb max DTE) to
> use under Linux with my BitSurfr Pro. After a little fiddling I got my
> scripts to work again (the fact that the BitSurfr can't autobaud into or out
> of 230Kb makes it a hassle. Also, you have to "trick" the Linux kernel into
> doing 230Kb because it doesn't yet know about that speed. That bit is easy).
>
> All-in-all, I was able to increase my NetPipes (a raw TCP stream connection)
> throughput from 9.1KB/sec to 10KB/sec by moving to the higher DTE. This still
> isn't the 14KB/sec FTP times my friend with a pair of Ciscos reports over his
> ISDN line.
>
> Maybe the Cisco is doing compression.
> Maybe I have some stupid arguments to pppd.
> Maybe the BitSurfr isn't terribly good at saturating either link.
> Maybe the PortMaster isn't terribly good at saturating either link.
> Maybe that's near the theoretical limit of an ISDN connection after you
> factor in the TCP overhead.
> Maybe I have exposed inefficiencies in Linux's software.
> Maybe BellSouth's switch isn't really giving me 128Kb.
> Maybe "dd" isn't efficient at spewing/slurping data (but it's good for
> counting out bytes from /dev/zeros).
> Maybe my cat is chewing on grass right now.
>
> I don't know. I'm disappointed, but it was only $33 after shipping, so I'm
> not jumping off any bridges (not that there's anything high enough in Florida
> to jump off and kill yourself).
>
> My BitSurfr is still rock-solid with ROM J. I think it's been up for ~4 days
> straight now. The only reason it disconnects at all is I'm either running
> diald, or I reboot the machine to play Warcraft II.
>