I don't know much about wiring but commonsense tells me that cables and wires on the outside of the house will wear out faster exposed to the elements. Did you know there is a new product that helps protect cable tv, phone lines and other low grade wires on the outside of homes?
The product is called TrimmerGuard. It uses a very high bond, exterior grade adhesive tape to ensure a strong and long lasting adhesion to the house or structure.
It also comes pre-drilled with screw holes to make it easier to adhere to wood siding and other types of exterior wall coverings. TrimmerGuard comes in black but can be easily painted to match the color of your house or exterior wall. This cable protector is easy to install and will last for years. It's now at US$9.95 for a limited time only.