Section: 6.6.1 Exchange of protocol configuration options 6.6.1.1 General
Content: The UE and the PDN GW can exchange protocol configuration options via the dedicated ESM information request procedure or via other ESM procedures. If supported by the network and UE end-to-end for a PDN connection, protocol configuration options shall be exchanged via the Extended protocol configuration options IE. Otherwise the Protocol configuration options IE is used. NOTE 1: In this version of the protocol inter-system mobility to and from NB-S1 mode is supported. During inter-system-mobility from NB-S1 mode to WB-S1 mode the end-to-end support of the Extended protocol configuration options IE can be lost, e.g. if the new MME does not support the Extended protocol configuration options IE. For the UE, the extended protocol configuration options is supported by the network and the UE end-to-end for a PDN connection if - the UE is in NB-S1 mode; - the APN requested for the PDN connection is for UAS services; - the PDN Type requested for the PDN connection is non-IP or Ethernet; - the network has indicated support of the Extended protocol configuration options IE in the last ATTACH ACCEPT or TRACKING AREA UPDATING ACCEPT message and the network has included the Extended protocol configuration options IE in at least one EPS session management message received by the UE for this PDN connection; or - a corresponding PDU session was transferred after inter-system change from N1 mode to S1 mode. For the MME, the extended protocol configuration options is supported by the network and the UE end-to-end for a PDN connection if - the UE is in NB-S1 mode; - the APN requested for the PDN connection is for UAS services; - the PDN Type requested for the PDN connection is non-IP or Ethernet; - the UE has indicated support of the Extended protocol configuration options IE in the last ATTACH REQUEST or TRACKING AREA UPDATING REQUEST message, and the MME has received the Extended protocol configuration options IE in at least one message sent by the PDN GW towards the UE for this PDN connection (for details see 3GPP TS 29.274[ 3GPP Evolved Packet System (EPS); Evolved General Packet Radio Service (GPRS) Tunnelling Protocol for Control plane (GTPv2-C); Stage 3 ]  [16D]); or - a corresponding PDU session was transferred after inter-system change from N1 mode to S1 mode. NOTE 2: For the PDN GW, the extended protocol configuration options is supported by the network and the UE end-to-end for a PDN connection if the last support indication received from the MME or S-GW indicates that extended protocol configuration options is supported for this PDN connection (for details see 3GPP TS 29.274[ 3GPP Evolved Packet System (EPS); Evolved General Packet Radio Service (GPRS) Tunnelling Protocol for Control plane (GTPv2-C); Stage 3 ]  [16D]).