The Gdd interface may be used to support a Diameter based signalling between a SGSN supporting EPS interfaces and the SMS GMSC or SMS IWMSC, as described in
clause 16.1.
An Interworking Function may be used for interworking between a SGSN supporting the Gdd interface (Diameter based), and a SMS-GMSC or SMS-IWMSC only supporting the Gd interface (MAP Based).