The Inter Operator Identifier (IOI) is shared between sending and receiving networks, service providers, or content providers. The orig-IOI
parameter is used by the originating network in the requests whereas the term-IOI
parameter is used by the terminating network in the responses.
As a P-CSCF, the SBC has the following abilities:
orig-IOI
in the REGISTER requests only. orig-IOI
in all the SIP requests and responses. While generating responses for any UE terminated requests, the SBC as a P-CSCF copies the orig-IOI
parameter received in the P-Charging-Vector header of the request to the P-Charging-Vector header of the response, and also includes a term-IOI
parameter. Both the orig-IOI
and term-IOI
parameters contain configured "Inter Operator ID" for the network.
The "Inter Operator ID" value associated with the Trunk Group towards the IMS core is used for the configuration.