The next step is beginning to match Littelfuse solutions to the previously discussed design challenges. The first step to obtaining a solution is answering the three questions shown here.  Armed with the answers to these questions, designers can consult a selection chart and come away with short list of specific part number options and detailed schematics for the application being considered. The first question is “What is the exposure level?” In other words, the kinds of threats to which the product will be exposed should be evaluated. Is this likely to be a “2 meter” application, or is the anticipation that there will be communication with equipment on another floor or in a remote part of the building? Is there a chance the application will be running outdoors or to the roof? Will this equipment be subjected to GR-1089? Inter-building or Intra-building? The second question is “Is Power over Ethernet involved?” If not, is there any chance that a PoE system might someday be attached to you equipment? PoE is a feature when designed-in, but it is a threat when it is not. When people see an RJ45 connector, they tend to plug in cables first and ask questions later. If not sure whether PoE will ever be involved with this system, it is best to default to a PoE solution. The last question is pretty easy and straightforward - “What is the data rate?” Is this a 100Base-TX system? Gig-E? Littelfuse can protect any of them. Knowing the data rate is required in order to select the proper solution.