Actor: User Application

Goal: Invoke Network Service

Description: Invokes a service that was previously located using a find service call.

Preconditions:

1. A service has been located.

1. The service is invoked on a remote peer.

Related Use Cases:

UC23.0 - Invoke Network Service (Async)
UC24.0 - Cancel Service Invocation
UC26.0 - Build Service Invocation Message
UC31.0 - Find Network Service

Notes and Issues:

1. The invocation is not guaranteed unless specified by the peer-to-peer library.

Event Flow:

1. The application locates the service (see UC31.0 - Find Network Service).
2. The application constructs the invocation message (see UC26.0 - Build Service Invocation Message).
3. The application asks the engine to perform the invocation.
4. The engine connects to the peer and sends the invocation message.
5. The engine waits for the response.
6. The engine, upon receiving a response (success or error), returns the response to the application.

UC22.1 Engine is not started

1. The application locates the service (see UC31.0 - Find Network Service).
2. The application constructs the invocation message (see UC26.0 - Build Service Invocation Message).
3. The application asks the engine to perform the invocation.
4. The engine returns an error that the it has not been started.

UC22.2 The peer is not available

1. The application locates the service (see UC31.0 - Find Network Service).
2. The application constructs the invocation message (see UC26.0 - Build Service Invocation Message).
3. The application asks the engine to perform the invocation.
4. The engine attempts to connect to the peer but determines that the peer is not currently available.
5. The engine returns an error that the peer is not available.

UC22.3 Timeout

1. The application locates the service (see UC31.0 - Find Network Service).
2. The application constructs the invocation message (see UC26.0 - Build Service Invocation Message).
3. The application asks the engine to perform the invocation.
4. The engine connects to the peer and sends the invocation message.
5. The engine waits for the response.
6. The engine, upon receiving a timeout, returns a timeout notice to the application.

Sequence Diagrams:

Revision History

Name	Date	Reason for Change	Version