To illustrate the architecture of the components at a high level, this
section describes two data flows. Figure 3 illustrates the two scenarios. These two scenarios
are described below.
Figure 3. Flow of a web services message

Request processing illustrates the sequence of events that
occurs when a collaboration makes a service call request to the connector to
invoke a web service. In this scenario, the collaboration plays the
role of a client, sending a request to a server.
- A
- The collaboration sends a service call request to the connector, which
calls the SOAP data handler to convert the business object to a SOAP request
message.
- B
- The connector invokes the web service WS2 by sending the SOAP
message. If the destination is an external web service, the connector
sends the SOAP message to a gateway. The gateway sends the SOAP message
to the endpoint corresponding to the destination web service. This
invokes the web service.
- C
- The invoked web service receives the SOAP request message and performs the
requested processing.
- D
- The invoked web service sends a SOAP response (or fault) message.
If the web service is external to the enterprise, a gateway receives and
routes the SOAP response message.
- E
- The SOAP response (or fault) message is routed back to the connector,
which calls the data handler to convert it to a response or fault business
object.
- F
- The connector returns the SOAP response or fault business object to the
collaboration.
Event processing illustrates the sequence of events that occurs
when a collaboration is called as a web service. In this scenario, the
collaboration, which is exposed as a web service, plays the role of the
server, accepting a request from a client, external or internal, and
responding as required.
- 1
- The client web service (WS1) sends a SOAP request message to the
destination specified in the WSDL document generated for the
collaboration.
- 2
- If the client web service is external, the gateway receives and routes the
message to the connector.
- 3
- The connector sends the SOAP message to the SOAP data handler to convert
the SOAP message to a business object. The connector invokes the
collaboration exposed as a web service.
- 4
- The collaboration returns a SOAP Response (or Fault) business
object.
- 5
- The connector calls the SOAP data handler to convert the SOAP Response (or
Fault) business object to a SOAP response message. The connector
returns the response to the gateway.
- 6
- If the client web service is external, the gateway routes the SOAP
response message to the client web service (WS1).
