IWF Ringback Support
When interworking SIP and H.323 to a gateway, PSTN gateway, or other endpoint, the Oracle® Enterprise Session Border Controller uses the mappings shown in the table below. The absence or presence of SDP in the SIP provisional message determines whether the tones are generated in-band or locally.
For each of the mappings listed in the following table, this section provides a sample call flow.
| SIP Message | H.323 Message |
|---|---|
| No Message | CallProceeding |
| No Message | Progress without PI |
| 183 with SDP | Progress with PI |
| 180 w/o SDP | Alert without PI |
| 180 with SDP | Alert with PI |
In the following diagram, a call that requires the IWF passes through the Oracle® Enterprise Session Border Controller twice, creating two call legs. The call originates from H.323 GW1 and terminates in Phone 1 or Phone 2.
