Adding UUI in NCC-SIP

Owned by Nathaniel Halbrooks
Dec 21, 2023
1 min read

Introduction

This article describes how to add User to User Information, i.e., UUI, to outgoing SIP INVITE and REFER messages when using Dialogic NaturalAccess™ SIP for NaturalCallControl™ API ("NCC-SIP"), as per specification draft-ietf-cuss-sip-uui.

Procedure

When issuing an INVITE, the following code needs to be added before the nccPlaceCall (immediately after SIP_IE_FROM_FULL_ADDRESS, before adding the SDP):

NCC_SIP_INFO_ADD_STR ( b, &ie, SIP_IE_OTHER_HEADER, "User-to-User:56a390f3d2b7310023a2;encoding=hex;purpose=foo;content=bar");

 

With this change, the following header will be sent in the outgoing INVITE:

User-to-User: 56a390f3d2b7310023a2;encoding=hex;purpose=foo;content=bar

 

Please note that a space after the colon gets added by the stack, so your code must NOT contain a space after "User-to-User:" when calling SIP_IE_OTHER_HEADER command, to get the proper one space in the outgoing INVITE message.

For the REFER message, draft-ietf-cuss-sip-uui-10 specifies that the User-to-User info should be encoded in the URI. This example uses the UUI from the example URI from the draft-ietf-cuss-sip-uui-10. This code is added directly before calling nccAutomaticTransfer:

NCC_SIP_INFO_ADD_STR ( b, &ie, SIP_IE_CONTACT_ADDRESS, "sip:+12125551212@gateway.example.com?User-to-User=56a390f3d2b7310023a2%3Bencoding%3Dhex%3Bpurpose%3Dfoo%3Bcontent%3Dbar");

 

With this change, the following is aded to the header line in the outgoing REFER:

 

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