Service Primitives
Service is defined by a set of primitives available to the user (or entities). Remember entities?
Primitives tell the service to perform some action or report an action taken by a peer entity.
Parameters: e.g., Connect.request(target-machine,type of service, max message size) or Connect.indication(callers-id, type of service, proposed max message size) more on this on the next page
Network software/Service primitives
An entity wants the service to do some work
An entity is to be informed about an event
An entity wants to respond to an event
The response to an earlier request has come back