7.7.124 UP Function Selection Indication Flags

29.0603GPPGeneral Packet Radio Service (GPRS)GPRS Tunnelling Protocol (GTP) across the Gn and Gp interfaceRelease 17TS

UP Function Selection Indication Flags is coded as depicted in Figure 7.7.124-1.

		Bits
	Octets	8	7	6	5	4	3		2	1
	1	Type = 224 (decimal)
	2 to 3	Length = n
	4	Spare	Spare	Spare	Spare	Spare	Spare	Spare		DCNR
	5 to (n+3)	These octet(s) is/are present only if explicitly specified

Figure 7.7.124-1: UP Function Selection Indication Flags

For each message, the applicable flags of the UP Function Selection Indication Flags IE shall be clearly specified in the individual message clause. The remaining flags of the UP Function Selection Indication Flags IE not so indicated shall be discarded by the receiver.

The receiver shall consider the value of the applicable flags as "0", if the UP Function Selection Indication Flags IE is applicable for the message but not included in the message by the sender.

The following bits within Octet 5 shall indicate:

– Bit 8 to 2 – Spare, for future use and set to zero.

– Bit 1 – DCNR (DCNR): if this bit is set to 1, it indicates to the PGW-C that it is desired to select a PGW-U optimized for Dual Connectivity with NR, e.g. for UEs indicating support of dual connectivity with NR in NAS signalling to the SGSN and without subscription restriction to use NR as secondary RAT.