Section: 6.5.1.4 UE requested PDN connectivity procedure not accepted by the network 6.5.1.4.1 General
Content: If connectivity with the requested PDN cannot be accepted by the network, the MME shall send a PDN CONNECTIVITY REJECT message to the UE. The message shall contain the PTI and an ESM cause value indicating the reason for rejecting the UE requested PDN connectivity. The ESM cause IE typically indicates one of the following ESM cause values: #8: operator determined barring; #26: insufficient resources; #27: missing or unknown APN; #28: unknown PDN type; #29: user authentication or authorization failed; #30: request rejected by Serving GW or PDN GW; #31: request rejected, unspecified; #32: service option not supported; #33: requested service option not subscribed; #34: service option temporarily out of order; #35: PTI already in use; #38: network failure; #50: PDN type IPv4 only allowed; #51: PDN type IPv6 only allowed; #53: ESM information not received; #54: PDN connection does not exist; #55: multiple PDN connections for a given APN not allowed; #57: PDN type IPv4v6 only allowed; #58: PDN type non IP only allowed; #61: PDN type Ethernet only allowed; #65: maximum number of EPS bearers reached; #66: requested APN not supported in current RAT and PLMN combination; #95 – 111: protocol errors; #112: APN restriction value incompatible with active EPS bearer context; #113: Multiple accesses to a PDN connection not allowed. The network may include a Back-off timer value IE in the PDN CONNECTIVITY REJECT message. If the ESM cause value is #26 "insufficient resources" and the PDN CONNECTIVITY REQUEST message was received via a NAS signalling connection established with RRC establishment cause "High priority access AC 11 – 15" or the request type in the PDN CONNECTIVITY REQUEST message was set to "emergency" or "handover of emergency bearer services", the network shall not include a Back-off timer value IE. If the ESM cause value is different from #26 "insufficient resources", #28 "unknown PDN type", #50 "PDN type IPv4 only allowed", #51 "PDN type IPv6 only allowed", #54 "PDN connection does not exist", #57 "PDN type IPv4v6 only allowed", #58 "PDN type non IP only allowed", #61 "PDN type Ethernet only allowed", #65 "maximum number of EPS bearers reached", and #66 "requested APN not supported in current RAT and PLMN combination", and the PDN CONNECTIVITY REQUEST message was received via a NAS signalling connection established with RRC establishment cause "High priority access AC 11 – 15", the network shall not include a Back-off timer value IE. If the Back-off timer value IE is included and the ESM cause value is different from #26 "insufficient resources", #50 "PDN type IPv4 only allowed", #51 "PDN type IPv6 only allowed", #57 "PDN type IPv4v6 only allowed", #58 "PDN type non IP only allowed", #61 "PDN type Ethernet only allowed", and #65 "maximum number of EPS bearers reached", the network may include the Re-attempt indicator IE to indicate: - whether the UE is allowed to attempt a PDP context activation procedure in the PLMN for the same in A/Gb or Iu mode or a PDU session establishment procedure in the PLMN for the same APN in N1 mode; and - whether another attempt in A/Gb and Iu mode, in S1 mode or in N1 mode is allowed in an equivalent PLMN. If the ESM cause value is #50 "PDN type IPv4 only allowed", #51 "PDN type IPv6 only allowed", #57 "PDN type IPv4v6 only allowed", #58 "PDN type non IP only allowed" or #61 "PDN type Ethernet only allowed", the network may include the Re-attempt indicator IE without Back-off timer value IE to indicate whether the UE is allowed to attempt a PDN connectivity procedure in an equivalent PLMN for the same APN in S1 mode using the same PDN type. If the ESM cause value is #66 "requested APN not supported in current RAT and PLMN combination", the network may include the Re-attempt indicator IE without Back-off timer value IE to indicate whether the UE is allowed to attempt a PDN connectivity procedure in an equivalent PLMN for the same APN in S1 mode. Upon receipt of the PDN CONNECTIVITY REJECT message, the UE shall stop timer T3482 and enter the state PROCEDURE TRANSACTION INACTIVE. If the PDN CONNECTIVITY REJECT message is due to an ESM failure notified by EMM layer (i.e., EMM cause #19 "ESM failure" included in an ATTACH REJECT message), the UE may include a different APN in the PDN CONNECTIVITY REQUEST message. NOTE 1: When receiving EMM cause #19 "ESM failure", coordination is required between the EMM and ESM sublayers in the UE to notify the ESM failure. If the PDN CONNECTIVITY REQUEST message was sent with request type set to "emergency" or "handover of emergency bearer services" in a stand-alone PDN connectivity procedure and the UE receives a PDN CONNECTIVITY REJECT message, then the UE may: a) inform the upper layers of the failure to establish the emergency bearer; or NOTE 2: This can result in the upper layers requesting establishment of a CS emergency call (if not already attempted in the CS domain) or other implementation specific mechanisms, e.g. procedures specified in 3GPP TS 24.229[ IP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3 ]  [13D] can result in the emergency call being attempted to another IP-CAN. b) detach locally, if not detached already, attempt EPS attach for emergency bearer services. If the PDN CONNECTIVITY REQUEST message was sent with PDN type set to "Ethernet" and the UE receives a PDN CONNECTIVITY REJECT message with ESM cause #58 "PDN type non IP only allowed", then the UE may attempt a PDN connectivity procedure with the non-IP PDN type. If the PDN CONNECTIVITY REJECT message contains the UAS services not allowed indication in the Extended protocol configuration options IE and the UE has not provided its CAA-level UAV ID to the network, the UE shall not send another PDN CONNECTIVITY REQUEST message for UAS services without providing its CAA-level UAV ID to the network. NOTE 3: If the PDN CONNECTIVITY REJECT message contains the UAS services not allowed indication in the Extended protocol configuration options IE, the ESM cause value #29 "user authentication or authorization failed" is included in the PDN CONNECTIVITY REJECT message. NOTE 4: The PDN CONNECTIVITY REJECT message contains the UAS services not allowed indication included in the Extended protocol configuration options IE, if the PDN connection is identified to be for UAS services based on the APN, and the CAA-level UAV ID is not provided by the UE in the request, or if the network is informed by the UAS NF that the UAS service is not allowed. NOTE 5: If the PDN CONNECTIVITY REQUEST message does not contain the SDNAEPC support indicator in the Protocol configuration options IE or the Extended protocol configuration options IE and the secondary DN authentication and authorization over EPC is mandatory due to local policies, the ESM cause value #29 "user authentication or authorization failed" can be included in the PDN CONNECTIVITY REJECT message".