When the IMG receives messaging on the inbound side the ISDN Parameter Filter object can be configured to either Pass or Don't Pass the UUI parameter information. If the UUI parameter is configured as Don't Pass the UUI parameters will be dropped and not interworked to the egress or outbound leg. See below for more information.
IMG EMS > Routing Configuration > Channel Groups > Channel Groups > ISDN Group > ISDN Parameter Filter
One ISDN Parameter Filter object can be created per ISDN ISUP Group object.
Don't Pass (Default) - Don't Pass user specific information not pertaining to the call from one user to another.
Pass - Pass specific User information not pertaining to the call from one user to another.