Call Hold and Transfer Basic Call

The following diagram show the signaling and media flows between the IP PBX and a softswitch. Note how the Oracle® Enterprise Session Border Controller is position to mediate flows between the two devices.

In the Call Proceeding messages forwarded to the IP PBX, the Oracle® Enterprise Session Border Controller uses a non-zero value to ensure that the IP PBX initiates an H.245 session. A progress indicator does not need to be included if the H.245 address is present in any of the following message types: Alerting, Progress, or Connect.

After the Oracle® Enterprise Session Border Controller receives a Call Proceeding message from the softswitch that contains the H.245 address, the Oracle® Enterprise Session Border Controller sends another Call Proceeding with its own H.245 address.

In the following call flow, the softswitch generates message to the gateway. These messages are:

• Initial Address Message (IAM)
• Address Complete Message (ACM)
• Answer Message (ANM)