[VoiceOps] Passing TRUNK GROUP IDENTITY through the Acme

SIP endpoint is using a "Trunk Group Identity" and needs to pass the information to Broadworks. How can the Acme be configured to pass it through? Example: Cisco IAD sends SIP registration towards Acme access realm and includes a Trunk Group Identity in its Contact header. Acme passes the SIP registration through to Broadworks but is not including the TGI in the Contact header of the Core realm. Ticket open with Acme for a few days but no updates. Tried to escalate. Thanks, Mark