I haven't looked at the Carrara content disk in much detail, but in the old Ray Dream Studio content disk, there was a nicely modeled chain link fence segment. If you're just wanting the fence and not looking to model it yourself, that is. Otherwise, and if it needs to stand up to close scrutiny, I'd do it in the spline modeler, creating each long wire strand using the pipeline extrusion, bending it appropriately. Having good reference photos (or even a real section of chain link) would be very helpful.