Logical Vs. Physical Network Design

Logical vs. Physical Network Design

The typical Top-Down approach to network design uses a systematic method to plan, design, and implement a new network. Generally, the Top-Down methodology involves analysis of the business requirements and goals, development of the logical design based on such goals, development of the physical design, and a phase for testing, optimizing, and documenting the network design. This paper focuses on the activities performed to create a logical design of a network and then goes on to explain how the physical design is created.

Logical Network Design

It is difficult to discuss the principles of the logical design without first discussing the importance of planning and analysis. After all, the goal of initial network planning is to ascertain enough information to create the logical network design proposal. Logical design begins by determining the need of the users. How does the business use a network to share information? What services does the network need to provide? What resources are needed? What are the requirements for network protocols, applications, performance, and security? These are the most important questions to consider in the beginning stages of design.

A network engineer must gather information such as projected traffic patterns and determine if there is a potential for bottlenecks. If this is the case, the design might require multiple communication paths to resources or the implementation of clustered servers with replicated data for load balancing. Also, the job functions of the clients must be studied. What are their jobs and work patterns and how does this affect the placement of servers, high-bandwidth links, and other physical components? Furthermore, a networ...

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...ing physical design of the same network (Figure 3).

Figure 2. Example of a logical network design diagram

Figure 3. Example physical network design diagram

References

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