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How to install 2nd modem with both serial ports already tied up?

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dannydanny

IS-IT--Management
Oct 9, 2002
109
DK
Hi,

I require another modem connected to our server so 2 people can dial in at once.
But the serial ports are tied up by a modem and a connection to the UPS.

I was thinking about installing an internal PCI modem, but I heard that it must share an IRQ with one of the existing COM ports, so performance is affected...

Are there any other ways of installing a second modem? Parallel port modem perhaps?

Thanks in advance,
Danny
 
USB modem, has the mainboard got USB? Replying helps further our knowledge, without comment leaves us wondering.
 
Hi,
If the mainboard hasn't got USB, as long as the operating system supports USB you can get an add-on card with USB ports.

Regards.
 
Surely they make add-on Serial Port PCI I/O boards also. Why buy USB when you need serial? If you do not like my post feel free to point out your opinion or my errors.
 
Perhaps, because he obviously hasn't bought a modem yet and USB is more versatile.

Regards.
 
They make the serial I/O cards, but what about the IRQs?
Wouldn't they still have to share?
 
A new IO card for serial ports will have to share IRQ's with existing devices on the PCI bus, most are set so that the IRQ is allocated by the BIOS on the board./
If you do get a USB modem make sure its a hardware based modem as some released are known to be HCF-software modems which require windows driver files to operate and you will definitely lose performance this route,, check the list on
If its compatible with Linux then its a hardware based modem and "should" work well??

If you have a free PCI slot on your computer then you should have a spare IRQ, usually when you get a board it will have a few unallocated IRQ's(9,10,11,12 etc), if One is taken up by the graphics card, one by the USB will that not leave at least 2(depending on you MB) for any PCI expansion cards...im not sure so maybe somebody can clarify this for me? Can he not allocate one of these to the PCI modem?i know they are low priority IRQ's but it shouldnt matter for modem data transfers across the Bus?

David
 
The UPS is the most likely safe candidate for sharing that I see...
 
hi all,

Thanks for all your suggestions. I guess I should have mentioned that the server does not have a USB port. So I guess a USB, or serial port PCI expansion is the way to go.... Is sharing a Com1 or Com2 port still required in this case?

Are they relatively easy and straight forward to install and configure? THis server is a critical mail server, so I don`t want to be messing around with it too much...if possible.

Thanks again, much appreciated,
Danny
 
Another option, get the USB add-in card and replace the Serial/UPS with one that uses USB connection. Relegate the old UPS to another computer that isn't as critical but could benefit, still cheaper than a new computer.
 
Aye, imho USB cards are generally easier to setup and have less to go wrong during the setup.
 
I have a modem pool of seven modems installed on a RAS server via a multiport serial controller card which adds an additional eight serial ports to the server. I believe they have something similar with USB. Here is the web site for the company from where you can purchase these.

 
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