The Flow Types of Service dialog (SETTINGS menu > Network Traffic Analysis > NTA Types of Service) lists the Flow Types of Service and their associated service IDs. Types of Service (ToS) is a part of an IP specification suite that allows routers to help prioritize traffic (according to the type of service requested). The ToS field is assigned by the routers on your network.
You can assign service type display names to make the Top Types of Service dashboard report more meaningful to you. By default Network Traffic Analysis is configured with the standard types of service.