Connecting a serial modem to a virtual machine running on ESXi

Recently during a vmware migration project I had a requirement to present a fax modem to a quite elderly installation of Tobit Faxware running on Windows 2003. I had planned to investigate replacing the serial modem with a usb model and testing a USB Anywhere product from Digi. Then I remembered some work I had done for a client who required direct connection of  serial devices to PCs through ethernet. Although this was a slightly different configuration with a pair of devices called Netports (nothing to do with Intel Netport printers) connected to the device being monitored and then linked via ethernet back to the PC monitoring it – I remembered that the product could be used in another way.

Digging out my test pair of Netports – and downloading the latest drivers and documentation from Alpha Micros I was able to configure the unit for connection to the lan and installation of the drivers into the phyical server prior to virtualisation to connect the physical serial modem to Tobit. The provided locater program is the best way to search for connected devices and to allow you to get access to reset the ip address of the unit.

 More detail about the unit

NetPort is a ‘plug-and-play’ Serial-to-Ethernet cable adaptor that enables any device or machine with a serial port, to become network and Internet-enabled in an instant.

The external NetPort adaptor features an integrated web server, allowing any device to which it is attached to be ‘contacted’ and monitored via a standard Internet browser. TCP/IP protocol stacks are embedded into the NetPort, enabling it to operate within non-PC environments and the adaptor features a Modem Emulation Mode, allowing it to behave like a modem but communicate over TCP/IP.  NetPort is a product which can be integrated into a system with minimal set-up, a configuration utility is provided which allows quick and easy customisation to suit any network or serial device.

Virtual Comm Port drivers are provided to allow a NetPort-connected device to communicate with existing software over TCP/IP (for Windows operating systems). Alternatively, ‘direct socket’ connection can be used.

The device configuration can be further extended using tools provided by the vendor to present your own web pages for configuration and information from the devices.

You can acquire these device from Openxtra at and tell Denis that Sentinel sent you !! I’ll let you know how the device performs in this configuration. I’m also anticipating using the same approach for UPS connection to a VM running on ESXi.