4.2 UUIE Response PDU: Use Case Scenario
This section describes a use case for the Alerting-UUIE Response PDU (section 2.2.9.3) in the NetMeeting protocol.
This use case involves two endpoints:
Endpoint 1 (the caller) makes a call to endpoint 2.
Endpoint 2 receives the call.
Endpoint 2 sends a request using the Alerting-UUIE Response PDU.
Endpoint 2 includes the following values in the request:
ProtocolIdentifier: This field contains the protocol version currently in use. NetMeeting sets this field to the string "0.0.8.225.0.2", for the H.225 protocol version 2.
DestinationInfo: This field contains the endpoint connection type. It can be a Terminal connection type or a Gateway connection type. The Terminal connection type is used in most cases.
CallIdentifier: This field is unique for each endpoint. In this use case, this field contains the unique endpoint GUID for Endpoint 2.
All other fields in the Alerting-UUIE Response PDU, although supported, are set to zero by Endpoint 2 and ignored by Endpoint 1.
The Alerting-UUIE Response PDU is encoded by Endpoint 2 and sent to Endpoint 1.
Endpoint 1 decodes the Alerting-UUIE Response PDU.
Endpoint 1 (the caller) performs the following actions:
Endpoint 1 indicates to the user that call establishment is in progress (rings).
Endpoint 1 sends a notification message to Endpoint 2.
This message indicates that Endpoint 1 is ready to proceed and currently awaits call acceptance from Endpoint 2.
Endpoint 1 identifies Endpoint 2 for this callback by setting the CallIdentifier field to the GUID for Endpoint 2.