The Service Advertising Protocol(SAP) is a NetWare protocol from Novell and is used to control the application. SAP allows file servers, routers and application servers to advertise their services and addresses.
Under SAP, services can be dynamically added and removed from the network. When servers are started, they advertise the services offered through SAP broadcasts. When a server is shut down, it uses SAP to indicate that the services will soon be unavailable. SAP information is loaded into a table that is made available to all nodes that request a particular service.