Actor: User Application

Goal: Invoke a network service asynchronously

Description: Invokes a service asynchronously 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:

UC22.0 - Invoke Network Service
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 framework.

Event Flow:

1. The application registers to be informed when the invocation response has been received.
2. The application locates the service (see UC31.0 - Find Network Service).
3. The application constructs the invocation message (see UC26.0 - Build Service Invocation Message).
4. The application asks the engine to perform the invocation.
5. The engine connects to the peer and sends the invocation message.
6. The engine waits for the response.
7. The engine, upon receiving a response (success or error), informs the registered application of the response.
8. The application removes its registration to listen for the invocation response.

UC23.1 Engine is not started

1. The application registers to be informed when the invocation response has been received.
2. The application locates the service (see UC31.0 - Find Network Service).
3. The application constructs the invocation message (see UC26.0 - Build Service Invocation Message).
4. The application asks the engine to perform the invocation.
5. The engine returns an error that the it has not been started.
6. The application removes its registration to listen for the invocation response.

UC23.2 The peer is not available

1. The application registers to be informed when the invocation response has been received.
2. The application locates the service (see UC31.0 - Find Network Service).
3. The application constructs the invocation message (see UC26.0 - Build Service Invocation Message).
4. The application asks the engine to perform the invocation.
5. The engine attempts to connect to the peer but determines that the peer is not currently available.
6. The engine returns an error that the peer is not available.
7. The application removes its registration to listen for the invocation response.

UC23.3 Timeout

1. The application registers to be informed when the invocation response has been received.
2. The application locates the service (see UC31.0 - Find Network Service).
3. The application constructs the invocation message (see UC26.0 - Build Service Invocation Message).
4. The application asks the engine to perform the invocation.
5. The engine connects to the peer and sends the invocation message.
6. The engine waits for the response.
7. The engine, upon receiving a timeout, informs the registered application of the timeout.
8. The application removes its registration to listen for the invocation response.

Sequence Diagrams:

Revision History

Name	Date	Reason for Change	Version