The three types of agents that NetWare 5 SLP uses are
User agents, which acquire service handles for user applications
Service agents, which advertise service handles
Directory agents, which collect service handles in internetworked enterprises
Applications running on a computer are represented by a User agent that understands the service and resource needs of the application. Each network service is represented by a Service agent, which makes it available to user agents. SLP dynamically maintains service attributes, so that a User agent can obtain current information.
Of the agents, the Directory Agents have the largest role in nds slp.