— The use of design patterns usually changes the approach of software design and makes software development relatively easy. This paper extends work on a forensic model for Logical Traffic Isolation (LTI) based on Differentiated Services (DiffServ) and designs the LTI model using different design patterns. Since design patterns add reliability, flexibility and reusability characteristics to a software system, this paper focuses on three design patterns in modeling the LTI architecture to achieve reusability and flexibility of the LTI model. This model is viewed as a three-tier architecture, which for experimental purposes is composed of the following components: traffic generator, DiffServ network and the sink server. The Mediator pattern is used to coordinate the traffic generator, sink server and, or preservation components, that is DiffServ domain is considered as the mediator. This study uses different design patterns to show how various patterns can be used to design the system....