I like the idea of asking the vendor for dongle free, but if that doesn't work, here is a tidbit on using USBoverIP.
We have a fax server VM that must have access to all it's modems at all times. When we first created it, Windows will NOT install the USB drivers properly, so to circumvent the problem, we created the VM in Workstation 5.5 at the time.
Since then, we have also used Server 1.x.
Set the VM config to have USB hardware, then load the OS. Don't worry about patches unless you need them for the OS to even support USB.
Then copy/upgrade the VM from Ws or Server to ESX 2.5 or 3.0. Be aware that there are incompatibilities on the vmdk (virtual disks) between versions. Check postings on upgrading virtual disks. It is a must or this won't work at all.
Since we used WS 5.5 to make VM for ESX 2.5, things worked ok, but we also had to recreate a development machine when the ESX array crashed.
The second time we used Server 1.x. VMware doesn't support this method, but I has worked for us.
1) Make the VM on WS 5.5, or Server 1.x with USB hardware, install Guest OS.
2) Make the VM on ESX 3.x and make sure you use the EXACT size for the virtual Disk (4 GB is NOT the same as 4,000 MB) Check the size of the vmdk file on the console or using the VMFS volume browser.
3) Copy the <vmnamed-flat.vmdk> (where vmname is the name you used for the VM, the -flat.vmdk is the actual content of the virtual drive) from the vmfs volume in WS 5.5 or Server 1.x to the location on the ESX 3.x were the VM will reside.
4) when you power up the VM you should see the machine boot as if you were on the WS 5.5 or Server 1.x. At this time the OS will have the USB support drivers and you can install any USBoverIP drivers you need.
We use DIGI USB-Anywhere to connect 12 FAX-Modem ports via USB and outside of the USB concentrator needing a dedicated IP address, it all works fine. We have been using this for over 1 year with out any problems.
To give you some comfort on this methods, we recently needed to test our FaxServer VM at a printer vendor's lab. We reversed the process of copying the -flat.vmdk back to Server 1.0.2 on WinXP Laptop after the VM had been created. It worked and the demo was productive.
The only thing that we have a small issue is that the USB Concentrator does NOT support USB 2.0 Speeds. It supports USB 2.0 devices, but because the connection to the net is 100 Mbps, the max speed supported is restricted by bandwidth of the net. We have tested a USB Flash drive but performance was slow, close to USB 1.1, even though the hw is 2.0.
Hope this helps. Expect to pay about $250 for the USBanywhere new. It does work in multiple other USB applications. We use several for CLI management of our network gear.
Good luck.
