23.0873GPPRelease 17Stage 2TSUser-to-User Signalling (UUS) supplementary service
7.1 Customised Applications for Mobile network Enhanced Logic (CAMEL)
7.2 Support for Optimal Routeing(SOR)
The invocation of Optimal Routeing in case of late call forwarding shall have no impact on the interactions of UUS with the call forwarding supplementary services as defined in clause 6.
The UUS request, UUI and UUS CF interaction indicator, if any, shall be added to the Resume Call Handling message in remote MSC when SOR late call forwarding is applied. For details refer to the procedure UUS_ICH_Handle_LCF in SDLs and the procedure Handle_ORLCF_VMSC (see GSM 03.79).
The UUS request and UUI, if any, shall be copied from the Resume Call Handling message to the IAM in GMSC when SOR late call forwarding is applied. For details refer to the procedure UUS_GMSC_Check_Forwarding in SDLs and the procedure OR_Handle_RCH (see GSM 03.79).
If UUS CF interaction indicator was present in Resume Call Handling message, the presence of UUS1 Service acceptance and UUI, if any, shall be modified during call setup time. For further details refer to the procedure MT_CF_MSC (see GSM 03.18) and UUS_MSC_Clear_UUS.