Cabletron Systems bridges, switches manual Abstracting the Design Process

Fast Ethernet

Abstracting the Design Process

As the Fast Ethernet switch selection field, shown in Table 7-2,contains only one device, the amount of decision-making remaining in the design process after the decision to use the Fast Ethernet technology is minimal. Due to the fact that the FN100-TX series is available with either eight or 16 switch interfaces and front panel ports that use either UTP or multimode fiber optic media, there are a few design issues left where decisions have to be made.

Media

To date, there are two media options available for Fast Ethernet networks: UTP and multimode fiber optics. The selection of a particular media for a Fast Ethernet network implementation must be accomplished before any hardware selection has been done. This is so the network radius and segment length calculations may be made and checked against the allowable maximums of the Fast Ethernet technology.

Port Count

As Fast Ethernet switches are not as easily expanded to accommodate new connections as stackable hubs are, it may be wise when designing a Fast Ethernet workgroup to provide extra connections. This kind of forethought can save the cost of purchasing another standalone device to provide network access to just one more station in the future.

Design Example

As an example of a high-end department implementing a Fast Ethernet network solution, let us examine a university mathematics lab consisting of 14 high-performance workstations which handle complex calculations and perform a variety of networked applications, including imaging, estimation, and series sorting. All of these stations are to be configured to connect to the Fast Ethernet network using Category 5 UTP cabling.

All of the stations in the laboratory have been determined to lie well within the maximum network radius of a Fast Ethernet network. The Network Designer plans to use switched Fast Ethernet as a networking technology, and intends to connect this workgroup to the campus network through a fiber optic Fast Ethernet connection to the facility hub, which handles all connections to the campus backbone network.

Fast Ethernet Workgroup Design 7-7