Network Designs

Introduction

Logical Network Design and Physical Network Design are different but depend on each other when implementing. The logical network design pertains more to a high-level view as opposed to the physical network design which is more of a low-level view.

Logical Network Design

A logical network design is the way the devices appear connected to the user. The logical network design is the way the data will be accessing the medium which is considered to be the logical topology, helping to provide the network backbone requirements and the overall systems and performance criteria. The logical design of the network is created first and is used to create the physical design. In the logical network design an example of IP addresses and how they are structured in their range is good to use. Machines are on the same network wire, but on separate networks which is what coins the term logical network. If there are IP address ranges such as 231.41.xx.x for approximately 20 machines, and IP address ranges such as 232.42.xx.x for 20 different machines, they are connected to the same network backbone but are on separate logical networks or in other words, have separate IP networks. The workstations on the two separate IP networks will be unable to talk to each other.

When planning, the logical design process will look at the amount of traffic and patterns which will be present on the network. There will be a need to locate potential bottlenecks and alleviate these by providing multiple paths to the various resources which will exist on the network. The organization will find a benefit in looking ahead to plan for any potential future growth so a system is not implemented which will not serve the purpose of the business a few years down the road. This logical network example looks at things in the upper layer and addresses the IP protocols of the network as aforementioned, and shows how things logically get to their intended locations:

(Cited from more.net, 2006)

Physical Network Design

The physical network design is the actual layout of the network and its media also referred to as the physical topology, highlighting the way the network is interconnected with wires and cables. This physical network design showcases exactly how the network will be implemented and how everything is interconnected. Some aspects of the physical network design are such things as the hubs, switches, routers, servers, and workstations which connect everything. We physically have machines which can see each other on this network setup.

The machines on a physical network can be connected via several methods and it is all dependent on what the network structure is. Some examples of physical network structures are token ring, Ethernet, and ATM. The token ring network is quite old and rarely used anymore. I remember when I first started working at my current job; we were on a token ring network. Over the past several years, it has been slowly phased out and replaced with switched fast Ethernet which is the technology on the wire on a switched environment, 100 Mbps to the desktops. Our network consists