VMWare ESX Server - Using Analog Modem Through Serial Port
Posted on 2008-10-16
We are using a banking package called Barclays Businessmaster on a virtual machine, which needs to use an analog modem for connections. Before now we used VMWare Server: the virtual machine used the serial port on the host server to see the modem, and after a little config this worked fine. We are now using ESX Server 3, and again have connected the physical serial port on the host to the relevant virtual machine. However, whilst the application can see the modem, and indeed can dialout, the line soon drops out (perhaps because of noise or some other comms failure). So for now we've returned this virtual machine to a VMWare Server running on a different physical host server (but with -exactly- the same hardware as the ESX Server). It works fine. So we know it's something to do with ESX Server rather than the host server hardware or the service we are trying to reach. I have tried lowering the port speed within the virtual machine itself, and have also called the support desk for Barclays BusinessMaster to ensure we have all the correct settings. Neither helped.
As a point of interest: for USB devices (not serial modems) we use DIGI AnywhereUSB, which works fine with things like smartcards and the like. However when I tried an analog USB modem (US Robotics) through this method it failed miserably - mostly it couldn't finish handshaking with the modem, and when it did the line would soon drop with comms failures. I have also tried using the Connexant serial modem over the network using a Keyspan Serial Port over Ethernet device, which was also stop-starty and didn't really work with the modem.
Host Server: Dell PE 2900 III + 2 x Quad Core Xeon E5410 (2.33GHz, 2x6MB, 1333MHz FSB) running ESX Server 3
Host Access: VI3 on Windows Server 2003 Standard
Modem: Connexant 56k Fax Modem (Serial)
Are there any known issues (+workarounds / configs) with regard to ESX Server and the serial port and/or dialup analog modems?
Are there any setups of serial or USB modems that are known to work with ESX Server virtual machines? Either using the serial port on the host server directly, or using serial / USB over ethernet solutions? (what is the exact modem and/or devices I would need to buy?).
Just one other point: The Barclays BusinessMaster application talks directly with the modem using (e.g.) ATDT commands, rather than Windows TAPI etc.
This is my first question, so apologies if it's badly formed or has been answered previously.