7.2.225 Terminating-IOI AVP

32.2993GPPCharging managementDiameter charging applicationsRelease 17Telecommunication managementTS

The Terminating-IOI AVP (AVP code 840) is of type UTF8String (alphanumeric string) and holds the Inter Operator Identifier (IOI) for the terminating network as generated by the IMS Network Element which takes responsibility for populating this parameter in a SIP response as described in RFC 7315 [404] and TS 24.229 [202].

The Terminating IOI contains the following values:

Type 1 IOI

– IOI of the home network where the S-CSCF is located for SIP responses directed to

the P-CSCF in the visited network when request was initiated by the served user

– IOI of the visited network where the TRF is located for SIP responses directed to

the S-CSCF in the home network when request was initiated by the served user and "VPLMN routing" is applied in a Roaming Architecture for Voice over IMS with Local breakout.

– IOI of the visited network where the P-CSCF is located for SIP responses directed to
the S-CSCF in the home network when request was terminated at the served user.

Type 2 IOI

– IOI of the home network of the terminating end user where the S-CSCF is located in case a
session is initiated toward the IMS. In case of redirection by the S-CSCF, Terminating-IOI AVP indicates the terminating party’s network operator to which the session is redirected.

– IOI of the terminating network where the MGCF is located in case a session is initiated from the IMS toward the PSTN.

Type 3 IOI

– IOI of the service provider network (originating side or terminating side) where the AS (proxy, terminating UA or redirect server or B2BUA) is located when receiving a SIP request as described in TS 24.229 [202].

– IOI of the home network operator contacted by an AS when an AS (originating UA or B2BUA) initiates a SIP request as described in TS 24.229 [202].

For further details on the Type 1, Type 2 and Type 3 IOIs, please refer to TS 32.240 [1].