Hi, i used to extend for 20 metres using a usb to cat 5 converter, (20 metres of cat 5 ethernet cable), the results were patchy at best, gave it up in the end and moved over to usb repeater extension cables, you can pick up a 20 metre one for £20, 30 metres seems to be double that price, anyway, works great, and my'n are outdoors effectively. IMO icam is a great prog, but if you start adding in any coverter the reliability factor can lessen greatly.
Sean