The products that are used and the complexity of the design that is implemented to secure any network perimeter will likely differ from one network to another because each design can be influenced to varying degrees by numerous different factors. Just a few of the factors that can influence a design are
Budget
Security required
Services offered
Remote access
User numbers
Cost-effectiveness
Management
Connectivity required
Regardless of which products are used within a particular perimeter security design, they should always provide the required functionality specified by the customer.Chapters 14, "Implementing Small SAFE Networks," and 16, "Implementing Medium-Size SAFE Networks."