The SBC supports User-to-User Information (UUI) interworking between SIP for Telephones (SIP-T) and SIP JJ90.30. This includes support for the User-to-User Indicator (0x2A). The SBC decodes/encodes the User-to-User Indicator (0x2A) parameter in P-N-ISUP-R header for the ACM message and CPG message. If the terminating carrier does not use User-User Information, interworking between the UUI parameter and a User-to-User header is not performed.

The SBC supports interworking between the UUI and User-to-User header in two scenarios:

  • Interworking of User-to-User Information (UUI) of ISUP MIME (SIP-T) to/from "User-to-User" header of the SIP message
  • Interworking of User-to-User Indicators (UUIN) of ISUP MIME (SIP-T) to/from "P-N-ISUP-R" header of the SIP message

UUI interworking is controlled by the SIP Trunk Group userToUserHdrSupport flag. For interworking in Japan, set the userToUserHdrSupport control to "sendrecv" on the JJ90.30 SIP trunk group.


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