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shimko

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Modem Connection Speed

I have a 28.8 modem and a P5 100 Mhz computer.  When I try to configure my modem to connect a speeds grater than 38400, I experience connection problems, often times loosing my connection.  It's like the connection degrades with time.  What could cause this to happen? Thanks in advance.
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rwenzla

Check your MB specs to see if your comports can handle that high of a speed.  
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ASKER

Thanks, I'll do that.  I've talked to a friend of mine who administers a large network over here in Honolulu and says it's the quality of my phone line connection.
Check ....this

setserial -a /dev/ttySX

where X is your serial port...
sometimes .. Linux gives you a free irq but
not the best ... if you have a dual boot ... check .. if the windows irq and the linux irq is the same!!
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ASKER

actually, I use /dev/cua1 for my dial out device. If the irqs are different, then what?
.. then put a line like 'setserial /dev/cua1 irq x' in Your local boot script which initializes the serial ports, usually /sbin.init.d/serial on SuSE, /etc/rc.d/init.d/serial (?) on RedHat. btw, with Kernel 2.2.x, using /dev/cua? is obsolete, You should use /dev/ttyS1 instead...
oops I meant /sbin/init.d not /sbin.init.d
/etc/rc.d/rc.local
is the right one!!
You've got a problem with the speed set to your modem port. You need to add in the end of your /etc/rc.d/rc.serial file a line like:

/sbin/setserial /dev/modem spd_vhi

 Just make sure your /dev/modem link is working, ok?

 Good luck!
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setserial spd_vhi should not be necessary if You have a kernel > 2.0,m since the serial driver now supports higher speeds. at my server, 3 serial ports work fine with spd_normal but 115k2 bps... But if You have a really odl kernel / software which doesn't support speeds > 38400 you'll want to set spd_vhi
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ASKER

Thanks everyone.  I used EatEmAndSmile's comment. I had to create the file /etc/rc.d/rc.serial with the command "setserial /dev/ttyS1 spd_vhi".  I changed my modem device to /dev/ttyS1 (from /dev/cua1).  Connection works great at 115200 bps. IRQ's were not an issue. EatEmAndSmile--respond with an answer so that I can give you the points.
Ok. If you'd also like to treat your modem by /dev/modem instead of /dev/ttyS1, you could create a symlink from /dev/ttyS1 to /dev/modem with:

 cd /dev
 ln -s ttyS1 modem

and modify the line in your /etc/rc.d/rc.serial file to

 /sbin/setserial /dev/modem spd_vhi

 Later!
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ASKER

please answer this for the 50 points, the answer was provided in EatEmAndSmile's comment! I want to close this question, thanks everyone!
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EatEmAndSmile

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