In some scenarios, the SBC may receive a term-ioi value in 200 OK (initial-INVITE) that is different from the previously received 18X values. If the term-ioi received in 200 OK is different from the 18x messages, the SBC relays the carrier code mapped from the new term-ioi information received in 200 OK towards the SIP-T side.

Note

The TTC Standards Organization in Japan has released the JJ90.30 specification for interconnection between IMS Operators. The SBC supports the JJ90.30 specification and interworks it with SIP variations. This feature is only applicable when the egress side of the call is using the JJ90.30 profile.


When a 200 OK is received with P-Charging-Vector header with new term-ioi different than previously received in 18x messages in SIP-T- SIP call, CPG (183) is generated at ingress leg to carry TLEC and "Event indicator" along with ANM (200OK).

The TLEC is fetched from new term-ioi value, then interworks the term-ioi into the Carrier Identification Code in SIP-T. 200 Ok maps to ANM (200OK) in SIP-T side. Since the ANM cannot carry the TLEC parameter, the SBC creates CPG (183) to carry TLEC and "Event indicator", and then sends ANM (200OK). The new term-ioi received in 200 Ok is written in the CAM and used for the rest of the signaling.

Backwards Call Indicators (BCI) are not included in the call progress (CPG) that the SBC generates.